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2013-02-24memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmapYasuaki Ishimatsu
For removing memmap region of sparse-vmemmap which is allocated bootmem, memmap region of sparse-vmemmap needs to be registered by get_page_bootmem(). So the patch searches pages of virtual mapping and registers the pages by get_page_bootmem(). NOTE: register_page_bootmem_memmap() is not implemented for ia64, ppc, s390, and sparc. So introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node() when platform doesn't support it. It's implemented by adding a new Kconfig option named CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected by memory-hotplug feature fully supported archs(currently only on x86_64). Since we have 2 config options called MEMORY_HOTPLUG and MEMORY_HOTREMOVE used for memory hot-add and hot-remove separately, and codes in function register_page_bootmem_info_node() are only used for collecting infomation for hot-remove, so reside it under MEMORY_HOTREMOVE. Besides page_isolation.c selected by MEMORY_ISOLATION under MEMORY_HOTPLUG is also such case, move it too. [mhocko@suse.cz: put register_page_bootmem_memmap inside CONFIG_MEMORY_HOTPLUG_SPARSE] [linfeng@cn.fujitsu.com: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node()] [mhocko@suse.cz: remove the arch specific functions without any implementation] [linfeng@cn.fujitsu.com: mm/Kconfig: move auto selects from MEMORY_HOTPLUG to MEMORY_HOTREMOVE as needed] [rientjes@google.com: fix defined but not used warning] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Wu Jianguo <wujianguo@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24memory-hotplug: introduce new arch_remove_memory() for removing page tableWen Congyang
For removing memory, we need to remove page tables. But it depends on architecture. So the patch introduce arch_remove_memory() for removing page table. Now it only calls __remove_pages(). Note: __remove_pages() for some archtecuture is not implemented (I don't know how to implement it for s390). Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24memory-hotplug: remove /sys/firmware/memmap/X sysfsYasuaki Ishimatsu
When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type} sysfs files are created. But there is no code to remove these files. This patch implements the function to remove them. We cannot free firmware_map_entry which is allocated by bootmem because there is no way to do so when the system is up. But we can at least remember the address of that memory and reuse the storage when the memory is added next time. This patch also introduces a new list map_entries_bootmem to link the map entries allocated by bootmem when they are removed, and a lock to protect it. And these entries will be reused when the memory is hot-added again. The idea is suggestted by Andrew Morton. NOTE: It is unsafe to return an entry pointer and release the map_entries_lock. So we should not hold the map_entries_lock separately in firmware_map_find_entry() and firmware_map_remove_entry(). Hold the map_entries_lock across find and remove /sys/firmware/memmap/X operation. And also, users of these two functions need to be careful to hold the lock when using these two functions. [tangchen@cn.fujitsu.com: Hold spinlock across find|remove /sys operation] [tangchen@cn.fujitsu.com: fix the wrong comments of map_entries] [tangchen@cn.fujitsu.com: reuse the storage of /sys/firmware/memmap/X/ allocated by bootmem] [tangchen@cn.fujitsu.com: fix section mismatch problem] [tangchen@cn.fujitsu.com: fix the doc format in drivers/firmware/memmap.c] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Julian Calaby <julian.calaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24memory-hotplug: remove redundant codesWen Congyang
offlining memory blocks and checking whether memory blocks are offlined are very similar. This patch introduces a new function to remove redundant codes. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24memory-hotplug: check whether all memory blocks are offlined or not when ↵Yasuaki Ishimatsu
removing memory We remove the memory like this: 1. lock memory hotplug 2. offline a memory block 3. unlock memory hotplug 4. repeat 1-3 to offline all memory blocks 5. lock memory hotplug 6. remove memory(TODO) 7. unlock memory hotplug All memory blocks must be offlined before removing memory. But we don't hold the lock in the whole operation. So we should check whether all memory blocks are offlined before step6. Otherwise, kernel maybe panicked. Offlining a memory block and removing a memory device can be two different operations. Users can just offline some memory blocks without removing the memory device. For this purpose, the kernel has held lock_memory_hotplug() in __offline_pages(). To reuse the code for memory hot-remove, we repeat step 1-3 to offline all the memory blocks, repeatedly lock and unlock memory hotplug, but not hold the memory hotplug lock in the whole operation. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24memory-hotplug: try to offline the memory twice to avoid dependenceWen Congyang
memory can't be offlined when CONFIG_MEMCG is selected. For example: there is a memory device on node 1. The address range is [1G, 1.5G). You will find 4 new directories memory8, memory9, memory10, and memory11 under the directory /sys/devices/system/memory/. If CONFIG_MEMCG is selected, we will allocate memory to store page cgroup when we online pages. When we online memory8, the memory stored page cgroup is not provided by this memory device. But when we online memory9, the memory stored page cgroup may be provided by memory8. So we can't offline memory8 now. We should offline the memory in the reversed order. When the memory device is hotremoved, we will auto offline memory provided by this memory device. But we don't know which memory is onlined first, so offlining memory may fail. In such case, iterate twice to offline the memory. 1st iterate: offline every non primary memory block. 2nd iterate: offline primary (i.e. first added) memory block. This idea is suggested by KOSAKI Motohiro. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: memory_hotplug: no need to check res twice in add_memorySasha Levin
Remove one redundant check of res. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: make do_mmap_pgoff return populate as a size in bytes, not as a boolMichel Lespinasse
do_mmap_pgoff() rounds up the desired size to the next PAGE_SIZE multiple, however there was no equivalent code in mm_populate(), which caused issues. This could be fixed by introduced the same rounding in mm_populate(), however I think it's preferable to make do_mmap_pgoff() return populate as a size rather than as a boolean, so we don't have to duplicate the size rounding logic in mm_populate(). Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: introduce VM_POPULATE flag to better deal with racy userspace programsMichel Lespinasse
The vm_populate() code populates user mappings without constantly holding the mmap_sem. This makes it susceptible to racy userspace programs: the user mappings may change while vm_populate() is running, and in this case vm_populate() may end up populating the new mapping instead of the old one. In order to reduce the possibility of userspace getting surprised by this behavior, this change introduces the VM_POPULATE vma flag which gets set on vmas we want vm_populate() to work on. This way vm_populate() may still end up populating the new mapping after such a race, but only if the new mapping is also one that the user has requested (using MAP_SHARED, MAP_LOCKED or mlock) to be populated. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: directly use __mlock_vma_pages_range() in find_extend_vma()Michel Lespinasse
In find_extend_vma(), we don't need mlock_vma_pages_range() to verify the vma type - we know we're working with a stack. So, we can call directly into __mlock_vma_pages_range(), and remove the last make_pages_present() call site. Note that we don't use mm_populate() here, so we can't release the mmap_sem while allocating new stack pages. This is deemed acceptable, because the stack vmas grow by a bounded number of pages at a time, and these are anon pages so we don't have to read from disk to populate them. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: remove flags argument to mmap_regionMichel Lespinasse
After the MAP_POPULATE handling has been moved to mmap_region() call sites, the only remaining use of the flags argument is to pass the MAP_NORESERVE flag. This can be just as easily handled by do_mmap_pgoff(), so do that and remove the mmap_region() flags parameter. [akpm@linux-foundation.org: remove double parens] Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: use mm_populate() for mremap() of VM_LOCKED vmasMichel Lespinasse
Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: use mm_populate() when adjusting brk with MCL_FUTURE in effectMichel Lespinasse
Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: use mm_populate() for blocking remap_file_pages()Michel Lespinasse
Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: introduce mm_populate() for populating new vmasMichel Lespinasse
When creating new mappings using the MAP_POPULATE / MAP_LOCKED flags (or with MCL_FUTURE in effect), we want to populate the pages within the newly created vmas. This may take a while as we may have to read pages from disk, so ideally we want to do this outside of the write-locked mmap_sem region. This change introduces mm_populate(), which is used to defer populating such mappings until after the mmap_sem write lock has been released. This is implemented as a generalization of the former do_mlock_pages(), which accomplished the same task but was using during mlock() / mlockall(). Signed-off-by: Michel Lespinasse <walken@google.com> Reported-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: remap_file_pages() fixesMichel Lespinasse
We have many vma manipulation functions that are fast in the typical case, but can optionally be instructed to populate an unbounded number of ptes within the region they work on: - mmap with MAP_POPULATE or MAP_LOCKED flags; - remap_file_pages() with MAP_NONBLOCK not set or when working on a VM_LOCKED vma; - mmap_region() and all its wrappers when mlock(MCL_FUTURE) is in effect; - brk() when mlock(MCL_FUTURE) is in effect. Current code handles these pte operations locally, while the sourrounding code has to hold the mmap_sem write side since it's manipulating vmas. This means we're doing an unbounded amount of pte population work with mmap_sem held, and this causes problems as Andy Lutomirski reported (we've hit this at Google as well, though it's not entirely clear why people keep trying to use mlock(MCL_FUTURE) in the first place). I propose introducing a new mm_populate() function to do this pte population work after the mmap_sem has been released. mm_populate() does need to acquire the mmap_sem read side, but critically, it doesn't need to hold it continuously for the entire duration of the operation - it can drop it whenever things take too long (such as when hitting disk for a file read) and re-acquire it later on. The following patches are included - Patches 1 fixes some issues I noticed while working on the existing code. If needed, they could potentially go in before the rest of the patches. - Patch 2 introduces the new mm_populate() function and changes mmap_region() call sites to use it after they drop mmap_sem. This is inspired from Andy Lutomirski's proposal and is built as an extension of the work I had previously done for mlock() and mlockall() around v2.6.38-rc1. I had tried doing something similar at the time but had given up as there were so many do_mmap() call sites; the recent cleanups by Linus and Viro are a tremendous help here. - Patches 3-5 convert some of the less-obvious places doing unbounded pte populates to the new mm_populate() mechanism. - Patches 6-7 are code cleanups that are made possible by the mm_populate() work. In particular, they remove more code than the entire patch series added, which should be a good thing :) - Patch 8 is optional to this entire series. It only helps to deal more nicely with racy userspace programs that might modify their mappings while we're trying to populate them. It adds a new VM_POPULATE flag on the mappings we do want to populate, so that if userspace replaces them with mappings it doesn't want populated, mm_populate() won't populate those replacement mappings. This patch: Assorted small fixes. The first two are quite small: - Move check for vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR) within existing if (!(vma->vm_flags & VM_NONLINEAR)) block. Purely cosmetic. - In the VM_LOCKED case, when dropping PG_Mlocked for the over-mapped range, make sure we own the mmap_sem write lock around the munlock_vma_pages_range call as this manipulates the vma's vm_flags. Last fix requires a longer explanation. remap_file_pages() can do its work either through VM_NONLINEAR manipulation or by creating extra vmas. These two cases were inconsistent with each other (and ultimately, both wrong) as to exactly when did they fault in the newly mapped file pages: - In the VM_NONLINEAR case, new file pages would be populated if the MAP_NONBLOCK flag wasn't passed. If MAP_NONBLOCK was passed, new file pages wouldn't be populated even if the vma is already marked as VM_LOCKED. - In the linear (emulated) case, the work is passed to the mmap_region() function which would populate the pages if the vma is marked as VM_LOCKED, and would not otherwise - regardless of the value of the MAP_NONBLOCK flag, because MAP_POPULATE wasn't being passed to mmap_region(). The desired behavior is that we want the pages to be populated and locked if the vma is marked as VM_LOCKED, or to be populated if the MAP_NONBLOCK flag is not passed to remap_file_pages(). Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: avoid calling pgdat_balanced() needlesslyZlatko Calusic
Now that balance_pgdat() is slightly tidied up, thanks to more capable pgdat_balanced(), it's become obvious that pgdat_balanced() is called to check the status, then break the loop if pgdat is balanced, just to be immediately called again. The second call is completely unnecessary, of course. The patch introduces pgdat_is_balanced boolean, which helps resolve the above suboptimal behavior, with the added benefit of slightly better documenting one other place in the function where we jump and skip lots of code. Signed-off-by: Zlatko Calusic <zlatko.calusic@iskon.hr> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: compaction: make __compact_pgdat() and compact_pgdat() return voidAndrew Morton
These functions always return 0. Formalise this. Cc: Jason Liu <r64343@freescale.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: make madvise(MADV_WILLNEED) support swap file prefetchShaohua Li
Make madvise(MADV_WILLNEED) support swap file prefetch. If memory is swapout, this syscall can do swapin prefetch. It has no impact if the memory isn't swapout. [akpm@linux-foundation.org: fix CONFIG_SWAP=n build] [sasha.levin@oracle.com: fix BUG on madvise early failure] Signed-off-by: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24memcg,vmscan: do not break out targeted reclaim without reclaimed pagesMichal Hocko
Targeted (hard resp soft) reclaim has traditionally tried to scan one group with decreasing priority until nr_to_reclaim (SWAP_CLUSTER_MAX pages) is reclaimed or all priorities are exhausted. The reclaim is then retried until the limit is met. This approach, however, doesn't work well with deeper hierarchies where groups higher in the hierarchy do not have any or only very few pages (this usually happens if those groups do not have any tasks and they have only re-parented pages after some of their children is removed). Those groups are reclaimed with decreasing priority pointlessly as there is nothing to reclaim from them. An easiest fix is to break out of the memcg iteration loop in shrink_zone only if the whole hierarchy has been visited or sufficient pages have been reclaimed. This is also more natural because the reclaimer expects that the hierarchy under the given root is reclaimed. As a result we can simplify the soft limit reclaim which does its own iteration. [yinghan@google.com: break out of the hierarchy loop only if nr_reclaimed exceeded nr_to_reclaim] [akpm@linux-foundation.org: use conventional comparison order] Signed-off-by: Michal Hocko <mhocko@suse.cz> Reported-by: Ying Han <yinghan@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <htejun@gmail.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Li Zefan <lizefan@huawei.com> Signed-off-by: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm/ksm.c: use new hashtable implementationSasha Levin
Switch ksm to use the new hashtable implementation. This reduces the amount of generic unrelated code in the ksm module. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm/huge_memory.c: use new hashtable implementationSasha Levin
Switch hugemem to use the new hashtable implementation. This reduces the amount of generic unrelated code in the hugemem. This also removes the dymanic allocation of the hash table. The upside is that we save a pointer dereference when accessing the hashtable, but we lose 8KB if CONFIG_TRANSPARENT_HUGEPAGE is enabled but the processor doesn't support hugepages. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: compaction: do not accidentally skip pageblocks in the migrate scannerMel Gorman
Compaction uses the ALIGN macro incorrectly with the migrate scanner by adding pageblock_nr_pages to a PFN. It happened to work when initially implemented as the starting PFN was also aligned but with caching restarts and isolating in smaller chunks this is no longer always true. The impact is that the migrate scanner scans outside its current pageblock. As pfn_valid() is still checked properly it does not cause any failure and the impact of the bug is that in some cases it will scan more than necessary when it crosses a page boundary but by no more than COMPACT_CLUSTER_MAX. It is highly unlikely this is even measurable but it's still wrong so this patch addresses the problem. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm/vmscan.c:__zone_reclaim(): replace max_t() with max()Andrew Morton
"mm: vmscan: save work scanning (almost) empty LRU lists" made SWAP_CLUSTER_MAX an unsigned long. Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Satoru Moriya <satoru.moriya@hds.com> Cc: Simon Jeons <simon.jeons@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm/page_alloc.c:__setup_per_zone_wmarks: make min_pages unsigned longAndrew Morton
`int' is an inappropriate type for a number-of-pages counter. While we're there, use the clamp() macro. Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Satoru Moriya <satoru.moriya@hds.com> Cc: Simon Jeons <simon.jeons@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: reduce rmap overhead for ex-KSM page copies created on swap faultsJohannes Weiner
When ex-KSM pages are faulted from swap cache, the fault handler is not capable of re-establishing anon_vma-spanning KSM pages. In this case, a copy of the page is created instead, just like during a COW break. These freshly made copies are known to be exclusive to the faulting VMA and there is no reason to go look for this page in parent and sibling processes during rmap operations. Use page_add_new_anon_rmap() for these copies. This also puts them on the proper LRU lists and marks them SwapBacked, so we can get rid of doing this ad-hoc in the KSM copy code. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Simon Jeons <simon.jeons@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Satoru Moriya <satoru.moriya@hds.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: vmscan: compaction works against zones, not lruvecsJohannes Weiner
The restart logic for when reclaim operates back to back with compaction is currently applied on the lruvec level. But this does not make sense, because the container of interest for compaction is a zone as a whole, not the zone pages that are part of a certain memory cgroup. Negative impact is bounded. For one, the code checks that the lruvec has enough reclaim candidates, so it does not risk getting stuck on a condition that can not be fulfilled. And the unfairness of hammering on one particular memory cgroup to make progress in a zone will be amortized by the round robin manner in which reclaim goes through the memory cgroups. Still, this can lead to unnecessary allocation latencies when the code elects to restart on a hard to reclaim or small group when there are other, more reclaimable groups in the zone. Move this logic to the zone level and restart reclaim for all memory cgroups in a zone when compaction requires more free pages from it. [akpm@linux-foundation.org: no need for min_t] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Satoru Moriya <satoru.moriya@hds.com> Cc: Simon Jeons <simon.jeons@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: vmscan: clean up get_scan_count()Johannes Weiner
Reclaim pressure balance between anon and file pages is calculated through a tuple of numerators and a shared denominator. Exceptional cases that want to force-scan anon or file pages configure the numerators and denominator such that one list is preferred, which is not necessarily the most obvious way: fraction[0] = 1; fraction[1] = 0; denominator = 1; goto out; Make this easier by making the force-scan cases explicit and use the fractionals only in case they are calculated from reclaim history. [akpm@linux-foundation.org: avoid using unintialized_var()] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Satoru Moriya <satoru.moriya@hds.com> Cc: Simon Jeons <simon.jeons@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: vmscan: improve comment on low-page cache handlingJohannes Weiner
Fix comment style and elaborate on why anonymous memory is force-scanned when file cache runs low. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Satoru Moriya <satoru.moriya@hds.com> Cc: Simon Jeons <simon.jeons@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: vmscan: clarify how swappiness, highest priority, memcg interactJohannes Weiner
A swappiness of 0 has a slightly different meaning for global reclaim (may swap if file cache really low) and memory cgroup reclaim (never swap, ever). In addition, global reclaim at highest priority will scan all LRU lists equal to their size and ignore other balancing heuristics. UNLESS swappiness forbids swapping, then the lists are balanced based on recent reclaim effectiveness. UNLESS file cache is running low, then anonymous pages are force-scanned. This (total mess of a) behaviour is implicit and not obvious from the way the code is organized. At least make it apparent in the code flow and document the conditions. It will be it easier to come up with sane semantics later. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Satoru Moriya <satoru.moriya@hds.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Simon Jeons <simon.jeons@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: vmscan: save work scanning (almost) empty LRU listsJohannes Weiner
In certain cases (kswapd reclaim, memcg target reclaim), a fixed minimum amount of pages is scanned from the LRU lists on each iteration, to make progress. Do not make this minimum bigger than the respective LRU list size, however, and save some busy work trying to isolate and reclaim pages that are not there. Empty LRU lists are quite common with memory cgroups in NUMA environments because there exists a set of LRU lists for each zone for each memory cgroup, while the memory of a single cgroup is expected to stay on just one node. The number of expected empty LRU lists is thus memcgs * (nodes - 1) * lru types Each attempt to reclaim from an empty LRU list does expensive size comparisons between lists, acquires the zone's lru lock etc. Avoid that. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Satoru Moriya <satoru.moriya@hds.com> Cc: Simon Jeons <simon.jeons@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm: memcg: only evict file pages when we have plentyJohannes Weiner
Commit e9868505987a ("mm, vmscan: only evict file pages when we have plenty") makes a point of not going for anonymous memory while there is still enough inactive cache around. The check was added only for global reclaim, but it is just as useful to reduce swapping in memory cgroup reclaim: 200M-memcg-defconfig-j2 vanilla patched Real time 454.06 ( +0.00%) 453.71 ( -0.08%) User time 668.57 ( +0.00%) 668.73 ( +0.02%) System time 128.92 ( +0.00%) 129.53 ( +0.46%) Swap in 1246.80 ( +0.00%) 814.40 ( -34.65%) Swap out 1198.90 ( +0.00%) 827.00 ( -30.99%) Pages allocated 16431288.10 ( +0.00%) 16434035.30 ( +0.02%) Major faults 681.50 ( +0.00%) 593.70 ( -12.86%) THP faults 237.20 ( +0.00%) 242.40 ( +2.18%) THP collapse 241.20 ( +0.00%) 248.50 ( +3.01%) THP splits 157.30 ( +0.00%) 161.40 ( +2.59%) Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Satoru Moriya <satoru.moriya@hds.com> Cc: Simon Jeons <simon.jeons@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24CMA: make putback_lru_pages() call conditionalSrinivas Pandruvada
As per documentation and other places calling putback_lru_pages(), putback_lru_pages() is called on error only. Make the CMA code behave consistently. [akpm@linux-foundation.org: remove a test-n-branch in the wrapup code] Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm/hugetlb.c: convert to pr_foo()Andrew Morton
Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24mm/memcontrol.c: convert printk(KERN_FOO) to pr_foo()Andrew Morton
Acked-by: Sha Zhengju <handai.szj@taobao.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-24memcg, oom: provide more precise dump info while memcg oom happeningSha Zhengju
Currently when a memcg oom is happening the oom dump messages is still global state and provides few useful info for users. This patch prints more pointed memcg page statistics for memcg-oom and take hierarchy into consideration: Based on Michal's advice, we take hierarchy into consideration: supppose we trigger an OOM on A's limit root_memcg | A (use_hierachy=1) / \ B C | D then the printed info will be: Memory cgroup stats for /A:... Memory cgroup stats for /A/B:... Memory cgroup stats for /A/C:... Memory cgroup stats for /A/B/D:... Following are samples of oom output: (1) Before change: mal-80 invoked oom-killer:gfp_mask=0xd0, order=0, oom_score_adj=0 mal-80 cpuset=/ mems_allowed=0 Pid: 2976, comm: mal-80 Not tainted 3.7.0+ #10 Call Trace: [<ffffffff8167fbfb>] dump_header+0x83/0x1ca ..... (call trace) [<ffffffff8168a818>] page_fault+0x28/0x30 <<<<<<<<<<<<<<<<<<<<< memcg specific information Task in /A/B/D killed as a result of limit of /A memory: usage 101376kB, limit 101376kB, failcnt 57 memory+swap: usage 101376kB, limit 101376kB, failcnt 0 kmem: usage 0kB, limit 9007199254740991kB, failcnt 0 <<<<<<<<<<<<<<<<<<<<< print per cpu pageset stat Mem-Info: Node 0 DMA per-cpu: CPU 0: hi: 0, btch: 1 usd: 0 ...... CPU 3: hi: 0, btch: 1 usd: 0 Node 0 DMA32 per-cpu: CPU 0: hi: 186, btch: 31 usd: 173 ...... CPU 3: hi: 186, btch: 31 usd: 130 <<<<<<<<<<<<<<<<<<<<< print global page state active_anon:92963 inactive_anon:40777 isolated_anon:0 active_file:33027 inactive_file:51718 isolated_file:0 unevictable:0 dirty:3 writeback:0 unstable:0 free:729995 slab_reclaimable:6897 slab_unreclaimable:6263 mapped:20278 shmem:35971 pagetables:5885 bounce:0 free_cma:0 <<<<<<<<<<<<<<<<<<<<< print per zone page state Node 0 DMA free:15836kB ... all_unreclaimable? no lowmem_reserve[]: 0 3175 3899 3899 Node 0 DMA32 free:2888564kB ... all_unrelaimable? no lowmem_reserve[]: 0 0 724 724 lowmem_reserve[]: 0 0 0 0 Node 0 DMA: 1*4kB (U) ... 3*4096kB (M) = 15836kB Node 0 DMA32: 41*4kB (UM) ... 702*4096kB (MR) = 2888316kB 120710 total pagecache pages 0 pages in swap cache <<<<<<<<<<<<<<<<<<<<< print global swap cache stat Swap cache stats: add 0, delete 0, find 0/0 Free swap = 499708kB Total swap = 499708kB 1040368 pages RAM 58678 pages reserved 169065 pages shared 173632 pages non-shared [ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name [ 2693] 0 2693 6005 1324 17 0 0 god [ 2754] 0 2754 6003 1320 16 0 0 god [ 2811] 0 2811 5992 1304 18 0 0 god [ 2874] 0 2874 6005 1323 18 0 0 god [ 2935] 0 2935 8720 7742 21 0 0 mal-30 [ 2976] 0 2976 21520 17577 42 0 0 mal-80 Memory cgroup out of memory: Kill process 2976 (mal-80) score 665 or sacrifice child Killed process 2976 (mal-80) total-vm:86080kB, anon-rss:69964kB, file-rss:344kB We can see that messages dumped by show_free_areas() are longsome and can provide so limited info for memcg that just happen oom. (2) After change mal-80 invoked oom-killer: gfp_mask=0xd0, order=0, oom_score_adj=0 mal-80 cpuset=/ mems_allowed=0 Pid: 2704, comm: mal-80 Not tainted 3.7.0+ #10 Call Trace: [<ffffffff8167fd0b>] dump_header+0x83/0x1d1 .......(call trace) [<ffffffff8168a918>] page_fault+0x28/0x30 Task in /A/B/D killed as a result of limit of /A <<<<<<<<<<<<<<<<<<<<< memcg specific information memory: usage 102400kB, limit 102400kB, failcnt 140 memory+swap: usage 102400kB, limit 102400kB, failcnt 0 kmem: usage 0kB, limit 9007199254740991kB, failcnt 0 Memory cgroup stats for /A: cache:32KB rss:30984KB mapped_file:0KB swap:0KB inactive_anon:6912KB active_anon:24072KB inactive_file:32KB active_file:0KB unevictable:0KB Memory cgroup stats for /A/B: cache:0KB rss:0KB mapped_file:0KB swap:0KB inactive_anon:0KB active_anon:0KB inactive_file:0KB active_file:0KB unevictable:0KB Memory cgroup stats for /A/C: cache:0KB rss:0KB mapped_file:0KB swap:0KB inactive_anon:0KB active_anon:0KB inactive_file:0KB active_file:0KB unevictable:0KB Memory cgroup stats for /A/B/D: cache:32KB rss:71352KB mapped_file:0KB swap:0KB inactive_anon:6656KB active_anon:64696KB inactive_file:16KB active_file:16KB unevictable:0KB [ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name [ 2260] 0 2260 6006 1325 18 0 0 god [ 2383] 0 2383 6003 1319 17 0 0 god [ 2503] 0 2503 6004 1321 18 0 0 god [ 2622] 0 2622 6004 1321 16 0 0 god [ 2695] 0 2695 8720 7741 22 0 0 mal-30 [ 2704] 0 2704 21520 17839 43 0 0 mal-80 Memory cgroup out of memory: Kill process 2704 (mal-80) score 669 or sacrifice child Killed process 2704 (mal-80) total-vm:86080kB, anon-rss:71016kB, file-rss:340kB This version provides more pointed info for memcg in "Memory cgroup stats for XXX" section. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23clean shmem_file_setup() a bitAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-23fs: Preserve error code in get_empty_filp(), part 2Anatol Pomozov
Allocating a file structure in function get_empty_filp() might fail because of several reasons: - not enough memory for file structures - operation is not allowed - user is over its limit Currently the function returns NULL in all cases and we loose the exact reason of the error. All callers of get_empty_filp() assume that the function can fail with ENFILE only. Return error through pointer. Change all callers to preserve this error code. [AV: cleaned up a bit, carved the get_empty_filp() part out into a separate commit (things remaining here deal with alloc_file()), removed pipe(2) behaviour change] Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-23new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm changes from Peter Anvin: "This is a huge set of several partly interrelated (and concurrently developed) changes, which is why the branch history is messier than one would like. The *really* big items are two humonguous patchsets mostly developed by Yinghai Lu at my request, which completely revamps the way we create initial page tables. In particular, rather than estimating how much memory we will need for page tables and then build them into that memory -- a calculation that has shown to be incredibly fragile -- we now build them (on 64 bits) with the aid of a "pseudo-linear mode" -- a #PF handler which creates temporary page tables on demand. This has several advantages: 1. It makes it much easier to support things that need access to data very early (a followon patchset uses this to load microcode way early in the kernel startup). 2. It allows the kernel and all the kernel data objects to be invoked from above the 4 GB limit. This allows kdump to work on very large systems. 3. It greatly reduces the difference between Xen and native (Xen's equivalent of the #PF handler are the temporary page tables created by the domain builder), eliminating a bunch of fragile hooks. The patch series also gets us a bit closer to W^X. Additional work in this pull is the 64-bit get_user() work which you were also involved with, and a bunch of cleanups/speedups to __phys_addr()/__pa()." * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits) x86, mm: Move reserving low memory later in initialization x86, doc: Clarify the use of asm("%edx") in uaccess.h x86, mm: Redesign get_user with a __builtin_choose_expr hack x86: Be consistent with data size in getuser.S x86, mm: Use a bitfield to mask nuisance get_user() warnings x86/kvm: Fix compile warning in kvm_register_steal_time() x86-32: Add support for 64bit get_user() x86-32, mm: Remove reference to alloc_remap() x86-32, mm: Remove reference to resume_map_numa_kva() x86-32, mm: Rip out x86_32 NUMA remapping code x86/numa: Use __pa_nodebug() instead x86: Don't panic if can not alloc buffer for swiotlb mm: Add alloc_bootmem_low_pages_nopanic() x86, 64bit, mm: hibernate use generic mapping_init x86, 64bit, mm: Mark data/bss/brk to nx x86: Merge early kernel reserve for 32bit and 64bit x86: Add Crash kernel low reservation x86, kdump: Remove crashkernel range find limit for 64bit memblock: Add memblock_mem_size() x86, boot: Not need to check setup_header version for setup_data ...
2013-02-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 update from Martin Schwidefsky: "The most prominent change in this patch set is the software dirty bit patch for s390. It removes __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY and the page_test_and_clear_dirty primitive which makes the common memory management code a bit less obscure. Heiko fixed most of the PCI related fallout, more often than not missing GENERIC_HARDIRQS dependencies. Notable is one of the 3270 patches which adds an export to tty_io to be able to resize a tty. The rest is the usual bunch of cleanups and bug fixes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits) s390/module: Add missing R_390_NONE relocation type drivers/gpio: add missing GENERIC_HARDIRQ dependency drivers/input: add couple of missing GENERIC_HARDIRQS dependencies s390/cleanup: rename SPP to LPP s390/mm: implement software dirty bits s390/mm: Fix crst upgrade of mmap with MAP_FIXED s390/linker skript: discard exit.data at runtime drivers/media: add missing GENERIC_HARDIRQS dependency s390/bpf,jit: add vlan tag support drivers/net,AT91RM9200: add missing GENERIC_HARDIRQS dependency iucv: fix kernel panic at reboot s390/Kconfig: sort list of arch selected config options phylib: remove !S390 dependeny from Kconfig uio: remove !S390 dependency from Kconfig dasd: fix sysfs cleanup in dasd_generic_remove s390/pci: fix hotplug module init s390/pci: cleanup clp page allocation s390/pci: cleanup clp inline assembly s390/perf: cpum_cf: fallback to software sampling events s390/mm: provide PAGE_SHARED define ...
2013-02-22Merge branch 'akpm' (incoming from Andrew)Linus Torvalds
Merge misc patches from Andrew Morton: - Florian has vanished so I appear to have become fbdev maintainer again :( - Joel and Mark are distracted to welcome to the new OCFS2 maintainer - The backlight queue - Small core kernel changes - lib/ updates - The rtc queue - Various random bits * akpm: (164 commits) rtc: rtc-davinci: use devm_*() functions rtc: rtc-max8997: use devm_request_threaded_irq() rtc: rtc-max8907: use devm_request_threaded_irq() rtc: rtc-da9052: use devm_request_threaded_irq() rtc: rtc-wm831x: use devm_request_threaded_irq() rtc: rtc-tps80031: use devm_request_threaded_irq() rtc: rtc-lp8788: use devm_request_threaded_irq() rtc: rtc-coh901331: use devm_clk_get() rtc: rtc-vt8500: use devm_*() functions rtc: rtc-tps6586x: use devm_request_threaded_irq() rtc: rtc-imxdi: use devm_clk_get() rtc: rtc-cmos: use dev_warn()/dev_dbg() instead of printk()/pr_debug() rtc: rtc-pcf8583: use dev_warn() instead of printk() rtc: rtc-sun4v: use pr_warn() instead of printk() rtc: rtc-vr41xx: use dev_info() instead of printk() rtc: rtc-rs5c313: use pr_err() instead of printk() rtc: rtc-at91rm9200: use dev_dbg()/dev_err() instead of printk()/pr_debug() rtc: rtc-rs5c372: use dev_dbg()/dev_warn() instead of printk()/pr_debug() rtc: rtc-ds2404: use dev_err() instead of printk() rtc: rtc-efi: use dev_err()/dev_warn()/pr_err() instead of printk() ...
2013-02-22block: optionally snapshot page contents to provide stable pages during writeDarrick J. Wong
This provides a band-aid to provide stable page writes on jbd without needing to backport the fixed locking and page writeback bit handling schemes of jbd2. The band-aid works by using bounce buffers to snapshot page contents instead of waiting. For those wondering about the ext3 bandage -- fixing the jbd locking (which was done as part of ext4dev years ago) is a lot of surgery, and setting PG_writeback on data pages when we actually hold the page lock dropped ext3 performance by nearly an order of magnitude. If we're going to migrate iscsi and raid to use stable page writes, the complaints about high latency will likely return. We might as well centralize their page snapshotting thing to one place. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22mm: only enforce stable page writes if the backing device requires itDarrick J. Wong
Create a helper function to check if a backing device requires stable page writes and, if so, performs the necessary wait. Then, make it so that all points in the memory manager that handle making pages writable use the helper function. This should provide stable page write support to most filesystems, while eliminating unnecessary waiting for devices that don't require the feature. Before this patchset, all filesystems would block, regardless of whether or not it was necessary. ext3 would wait, but still generate occasional checksum errors. The network filesystems were left to do their own thing, so they'd wait too. After this patchset, all the disk filesystems except ext3 and btrfs will wait only if the hardware requires it. ext3 (if necessary) snapshots pages instead of blocking, and btrfs provides its own bdi so the mm will never wait. Network filesystems haven't been touched, so either they provide their own stable page guarantees or they don't block at all. The blocking behavior is back to what it was before 3.0 if you don't have a disk requiring stable page writes. Here's the result of using dbench to test latency on ext2: 3.8.0-rc3: Operation Count AvgLat MaxLat ---------------------------------------- WriteX 109347 0.028 59.817 ReadX 347180 0.004 3.391 Flush 15514 29.828 287.283 Throughput 57.429 MB/sec 4 clients 4 procs max_latency=287.290 ms 3.8.0-rc3 + patches: WriteX 105556 0.029 4.273 ReadX 335004 0.005 4.112 Flush 14982 30.540 298.634 Throughput 55.4496 MB/sec 4 clients 4 procs max_latency=298.650 ms As you can see, the maximum write latency drops considerably with this patch enabled. The other filesystems (ext3/ext4/xfs/btrfs) behave similarly, but see the cover letter for those results. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22bdi: allow block devices to say that they require stable page writesDarrick J. Wong
This patchset ("stable page writes, part 2") makes some key modifications to the original 'stable page writes' patchset. First, it provides creators (devices and filesystems) of a backing_dev_info a flag that declares whether or not it is necessary to ensure that page contents cannot change during writeout. It is no longer assumed that this is true of all devices (which was never true anyway). Second, the flag is used to relaxed the wait_on_page_writeback calls so that wait only occurs if the device needs it. Third, it fixes up the remaining disk-backed filesystems to use this improved conditional-wait logic to provide stable page writes on those filesystems. It is hoped that (for people not using checksumming devices, anyway) this patchset will give back unnecessary performance decreases since the original stable page write patchset went into 3.0. Sorry about not fixing it sooner. Complaints were registered by several people about the long write latencies introduced by the original stable page write patchset. Generally speaking, the kernel ought to allocate as little extra memory as possible to facilitate writeout, but for people who simply cannot wait, a second page stability strategy is (re)introduced: snapshotting page contents. The waiting behavior is still the default strategy; to enable page snapshotting, a superblock flag (MS_SNAP_STABLE) must be set. This flag is used to bandaid^Henable stable page writeback on ext3[1], and is not used anywhere else. Given that there are already a few storage devices and network FSes that have rolled their own page stability wait/page snapshot code, it would be nice to move towards consolidating all of these. It seems possible that iscsi and raid5 may wish to use the new stable page write support to enable zero-copy writeout. Thank you to Jan Kara for helping fix a couple more filesystems. Per Andrew Morton's request, here are the result of using dbench to measure latencies on ext2: 3.8.0-rc3: Operation Count AvgLat MaxLat ---------------------------------------- WriteX 109347 0.028 59.817 ReadX 347180 0.004 3.391 Flush 15514 29.828 287.283 Throughput 57.429 MB/sec 4 clients 4 procs max_latency=287.290 ms 3.8.0-rc3 + patches: WriteX 105556 0.029 4.273 ReadX 335004 0.005 4.112 Flush 14982 30.540 298.634 Throughput 55.4496 MB/sec 4 clients 4 procs max_latency=298.650 ms As you can see, for ext2 the maximum write latency decreases from ~60ms on a laptop hard disk to ~4ms. I'm not sure why the flush latencies increase, though I suspect that being able to dirty pages faster gives the flusher more work to do. On ext4, the average write latency decreases as well as all the maximum latencies: 3.8.0-rc3: WriteX 85624 0.152 33.078 ReadX 272090 0.010 61.210 Flush 12129 36.219 168.260 Throughput 44.8618 MB/sec 4 clients 4 procs max_latency=168.276 ms 3.8.0-rc3 + patches: WriteX 86082 0.141 30.928 ReadX 273358 0.010 36.124 Flush 12214 34.800 165.689 Throughput 44.9941 MB/sec 4 clients 4 procs max_latency=165.722 ms XFS seems to exhibit similar latency improvements as ext2: 3.8.0-rc3: WriteX 125739 0.028 104.343 ReadX 399070 0.005 4.115 Flush 17851 25.004 131.390 Throughput 66.0024 MB/sec 4 clients 4 procs max_latency=131.406 ms 3.8.0-rc3 + patches: WriteX 123529 0.028 6.299 ReadX 392434 0.005 4.287 Flush 17549 25.120 188.687 Throughput 64.9113 MB/sec 4 clients 4 procs max_latency=188.704 ms ...and btrfs, just to round things out, also shows some latency decreases: 3.8.0-rc3: WriteX 67122 0.083 82.355 ReadX 212719 0.005 2.828 Flush 9547 47.561 147.418 Throughput 35.3391 MB/sec 4 clients 4 procs max_latency=147.433 ms 3.8.0-rc3 + patches: WriteX 64898 0.101 71.631 ReadX 206673 0.005 7.123 Flush 9190 47.963 219.034 Throughput 34.0795 MB/sec 4 clients 4 procs max_latency=219.044 ms Before this patchset, all filesystems would block, regardless of whether or not it was necessary. ext3 would wait, but still generate occasional checksum errors. The network filesystems were left to do their own thing, so they'd wait too. After this patchset, all the disk filesystems except ext3 and btrfs will wait only if the hardware requires it. ext3 (if necessary) snapshots pages instead of blocking, and btrfs provides its own bdi so the mm will never wait. Network filesystems haven't been touched, so either they provide their own wait code, or they don't block at all. The blocking behavior is back to what it was before 3.0 if you don't have a disk requiring stable page writes. This patchset has been tested on 3.8.0-rc3 on x64 with ext3, ext4, and xfs. I've spot-checked 3.8.0-rc4 and seem to be getting the same results as -rc3. [1] The alternative fixes to ext3 include fixing the locking order and page bit handling like we did for ext4 (but then why not just use ext4?), or setting PG_writeback so early that ext3 becomes extremely slow. I tried that, but the number of write()s I could initiate dropped by nearly an order of magnitude. That was a bit much even for the author of the stable page series! :) This patch: Creates a per-backing-device flag that tracks whether or not pages must be held immutable during writeout. Eventually it will be used to waive wait_for_page_writeback() if nothing requires stable pages. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21Merge tag 'driver-core-3.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core patches from Greg Kroah-Hartman: "Here is the big driver core merge for 3.9-rc1 There are two major series here, both of which touch lots of drivers all over the kernel, and will cause you some merge conflicts: - add a new function called devm_ioremap_resource() to properly be able to check return values. - remove CONFIG_EXPERIMENTAL Other than those patches, there's not much here, some minor fixes and updates" Fix up trivial conflicts * tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (221 commits) base: memory: fix soft/hard_offline_page permissions drivercore: Fix ordering between deferred_probe and exiting initcalls backlight: fix class_find_device() arguments TTY: mark tty_get_device call with the proper const values driver-core: constify data for class_find_device() firmware: Ignore abort check when no user-helper is used firmware: Reduce ifdef CONFIG_FW_LOADER_USER_HELPER firmware: Make user-mode helper optional firmware: Refactoring for splitting user-mode helper code Driver core: treat unregistered bus_types as having no devices watchdog: Convert to devm_ioremap_resource() thermal: Convert to devm_ioremap_resource() spi: Convert to devm_ioremap_resource() power: Convert to devm_ioremap_resource() mtd: Convert to devm_ioremap_resource() mmc: Convert to devm_ioremap_resource() mfd: Convert to devm_ioremap_resource() media: Convert to devm_ioremap_resource() iommu: Convert to devm_ioremap_resource() drm: Convert to devm_ioremap_resource() ...
2013-02-21Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: "The biggest part of this pull request is a patch series from Maxim Patlasov to optimize scatter-gather direct IO. There's also the addition of a "readdirplus" API, poll events and various fixes and cleanups. There's a one line change outside of fuse to mm/filemap.c which makes the argument of iov_iter_single_seg_count() const, required by Maxim's patches." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (22 commits) fuse: allow control of adaptive readdirplus use Synchronize fuse header with one used in library fuse: send poll events fuse: don't WARN when nlink is zero fuse: avoid out-of-scope stack access fuse: bump version for READDIRPLUS FUSE: Adapt readdirplus to application usage patterns Do not use RCU for current process credentials fuse: cleanup fuse_direct_io() fuse: optimize __fuse_direct_io() fuse: optimize fuse_get_user_pages() fuse: pass iov[] to fuse_get_user_pages() mm: minor cleanup of iov_iter_single_seg_count() fuse: use req->page_descs[] for argpages cases fuse: add per-page descriptor <offset, length> to fuse_req fuse: rework fuse_do_ioctl() fuse: rework fuse_perform_write() fuse: rework fuse_readpages() fuse: rework fuse_retrieve() fuse: categorize fuse_get_req() ...
2013-02-20Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler changes from Ingo Molnar: "Main changes: - scheduler side full-dynticks (user-space execution is undisturbed and receives no timer IRQs) preparation changes that convert the cputime accounting code to be full-dynticks ready, from Frederic Weisbecker. - Initial sched.h split-up changes, by Clark Williams - select_idle_sibling() performance improvement by Mike Galbraith: " 1 tbench pair (worst case) in a 10 core + SMT package: pre 15.22 MB/sec 1 procs post 252.01 MB/sec 1 procs " - sched_rr_get_interval() ABI fix/change. We think this detail is not used by apps (so it's not an ABI in practice), but lets keep it under observation. - misc RT scheduling cleanups, optimizations" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h> cputime: Remove irqsave from seqlock readers sched, powerpc: Fix sched.h split-up build failure cputime: Restore CPU_ACCOUNTING config defaults for PPC64 sched/rt: Move rt specific bits into new header file sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice sched: Move sched.h sysctl bits into separate header sched: Fix signedness bug in yield_to() sched: Fix select_idle_sibling() bouncing cow syndrome sched/rt: Further simplify pick_rt_task() sched/rt: Do not account zero delta_exec in update_curr_rt() cputime: Safely read cputime of full dynticks CPUs kvm: Prepare to add generic guest entry/exit callbacks cputime: Use accessors to read task cputime stats cputime: Allow dynamic switch between tick/virtual based cputime accounting cputime: Generic on-demand virtual cputime accounting cputime: Move default nsecs_to_cputime() to jiffies based cputime file cputime: Librarize per nsecs resolution cputime definitions cputime: Avoid multiplication overflow on utime scaling context_tracking: Export context state for generic vtime ... Fix up conflict in kernel/context_tracking.c due to comment additions.
2013-02-18mm: fix pageblock bitmap allocationLinus Torvalds
Commit c060f943d092 ("mm: use aligned zone start for pfn_to_bitidx calculation") fixed out calculation of the index into the pageblock bitmap when a !SPARSEMEM zome was not aligned to pageblock_nr_pages. However, the _allocation_ of that bitmap had never taken this alignment requirement into accout, so depending on the exact size and alignment of the zone, the use of that index could then access past the allocation, resulting in some very subtle memory corruption. This was reported (and bisected) by Ingo Molnar: one of his random config builds would hang with certain very specific kernel command line options. In the meantime, commit c060f943d092 has been marked for stable, so this fix needs to be back-ported to the stable kernels that backported the commit to use the right alignment. Bisected-and-tested-by: Ingo Molnar <mingo@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-14s390/mm: implement software dirty bitsMartin Schwidefsky
The s390 architecture is unique in respect to dirty page detection, it uses the change bit in the per-page storage key to track page modifications. All other architectures track dirty bits by means of page table entries. This property of s390 has caused numerous problems in the past, e.g. see git commit ef5d437f71afdf4a "mm: fix XFS oops due to dirty pages without buffers on s390". To avoid future issues in regard to per-page dirty bits convert s390 to a fault based software dirty bit detection mechanism. All user page table entries which are marked as clean will be hardware read-only, even if the pte is supposed to be writable. A write by the user process will trigger a protection fault which will cause the user pte to be marked as dirty and the hardware read-only bit is removed. With this change the dirty bit in the storage key is irrelevant for Linux as a host, but the storage key is still required for KVM guests. The effect is that page_test_and_clear_dirty and the related code can be removed. The referenced bit in the storage key is still used by the page_test_and_clear_young primitive to provide page age information. For page cache pages of mappings with mapping_cap_account_dirty there will not be any change in behavior as the dirty bit tracking already uses read-only ptes to control the amount of dirty pages. Only for swap cache pages and pages of mappings without mapping_cap_account_dirty there can be additional protection faults. To avoid an excessive number of additional faults the mk_pte primitive checks for PageDirty if the pgprot value allows for writes and pre-dirties the pte. That avoids all additional faults for tmpfs and shmem pages until these pages are added to the swap cache. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>