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author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2013-11-12 23:07:50 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-13 03:09:07 (GMT) |
commit | 46c77e2bb07eba3b38edfec76873f12942c49dd3 (patch) | |
tree | 2e6dd491627079f3e377e948f23137dd0c4cab40 | |
parent | ec8e41aec13005fed0dbee002fb8c99b4e001d50 (diff) | |
download | linux-fsl-qoriq-46c77e2bb07eba3b38edfec76873f12942c49dd3.tar.xz |
tools/vm/page-types.c: support KPF_SOFTDIRTY bit
Soft dirty bit allows us to track which pages are written since the last
clear_ref (by "echo 4 > /proc/pid/clear_refs".) This is useful for
userspace applications to know their memory footprints.
Note that the kernel exposes this flag via bit[55] of /proc/pid/pagemap,
and the semantics is not a default one (scheduled to be the default in the
near future.) However, it shifts to the new semantics at the first
clear_ref, and the users of soft dirty bit always do it before utilizing
the bit, so that's not a big deal. Users must avoid relying on the bit in
page-types before the first clear_ref.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | include/linux/kernel-page-flags.h | 1 | ||||
-rw-r--r-- | tools/vm/page-types.c | 32 |
2 files changed, 21 insertions, 12 deletions
diff --git a/include/linux/kernel-page-flags.h b/include/linux/kernel-page-flags.h index 546eb6a..f65ce09 100644 --- a/include/linux/kernel-page-flags.h +++ b/include/linux/kernel-page-flags.h @@ -15,5 +15,6 @@ #define KPF_OWNER_PRIVATE 37 #define KPF_ARCH 38 #define KPF_UNCACHED 39 +#define KPF_SOFTDIRTY 40 #endif /* LINUX_KERNEL_PAGE_FLAGS_H */ diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c index 71c9c25..d5e9d6d 100644 --- a/tools/vm/page-types.c +++ b/tools/vm/page-types.c @@ -59,12 +59,14 @@ #define PM_PSHIFT_BITS 6 #define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS) #define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET) -#define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK) +#define __PM_PSHIFT(x) (((uint64_t) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK) #define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1) #define PM_PFRAME(x) ((x) & PM_PFRAME_MASK) +#define __PM_SOFT_DIRTY (1LL) #define PM_PRESENT PM_STATUS(4LL) #define PM_SWAP PM_STATUS(2LL) +#define PM_SOFT_DIRTY __PM_PSHIFT(__PM_SOFT_DIRTY) /* @@ -83,6 +85,7 @@ #define KPF_OWNER_PRIVATE 37 #define KPF_ARCH 38 #define KPF_UNCACHED 39 +#define KPF_SOFTDIRTY 40 /* [48-] take some arbitrary free slots for expanding overloaded flags * not part of kernel API @@ -132,6 +135,7 @@ static const char * const page_flag_names[] = { [KPF_OWNER_PRIVATE] = "O:owner_private", [KPF_ARCH] = "h:arch", [KPF_UNCACHED] = "c:uncached", + [KPF_SOFTDIRTY] = "f:softdirty", [KPF_READAHEAD] = "I:readahead", [KPF_SLOB_FREE] = "P:slob_free", @@ -417,7 +421,7 @@ static int bit_mask_ok(uint64_t flags) return 1; } -static uint64_t expand_overloaded_flags(uint64_t flags) +static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme) { /* SLOB/SLUB overload several page flags */ if (flags & BIT(SLAB)) { @@ -433,6 +437,9 @@ static uint64_t expand_overloaded_flags(uint64_t flags) if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM)) flags ^= BIT(RECLAIM) | BIT(READAHEAD); + if (pme & PM_SOFT_DIRTY) + flags |= BIT(SOFTDIRTY); + return flags; } @@ -448,11 +455,11 @@ static uint64_t well_known_flags(uint64_t flags) return flags; } -static uint64_t kpageflags_flags(uint64_t flags) +static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme) { - flags = expand_overloaded_flags(flags); - - if (!opt_raw) + if (opt_raw) + flags = expand_overloaded_flags(flags, pme); + else flags = well_known_flags(flags); return flags; @@ -545,9 +552,9 @@ static size_t hash_slot(uint64_t flags) } static void add_page(unsigned long voffset, - unsigned long offset, uint64_t flags) + unsigned long offset, uint64_t flags, uint64_t pme) { - flags = kpageflags_flags(flags); + flags = kpageflags_flags(flags, pme); if (!bit_mask_ok(flags)) return; @@ -569,7 +576,8 @@ static void add_page(unsigned long voffset, #define KPAGEFLAGS_BATCH (64 << 10) /* 64k pages */ static void walk_pfn(unsigned long voffset, unsigned long index, - unsigned long count) + unsigned long count, + uint64_t pme) { uint64_t buf[KPAGEFLAGS_BATCH]; unsigned long batch; @@ -583,7 +591,7 @@ static void walk_pfn(unsigned long voffset, break; for (i = 0; i < pages; i++) - add_page(voffset + i, index + i, buf[i]); + add_page(voffset + i, index + i, buf[i], pme); index += pages; count -= pages; @@ -608,7 +616,7 @@ static void walk_vma(unsigned long index, unsigned long count) for (i = 0; i < pages; i++) { pfn = pagemap_pfn(buf[i]); if (pfn) - walk_pfn(index + i, pfn, 1); + walk_pfn(index + i, pfn, 1, buf[i]); } index += pages; @@ -659,7 +667,7 @@ static void walk_addr_ranges(void) for (i = 0; i < nr_addr_ranges; i++) if (!opt_pid) - walk_pfn(0, opt_offset[i], opt_size[i]); + walk_pfn(0, opt_offset[i], opt_size[i], 0); else walk_task(opt_offset[i], opt_size[i]); |