summaryrefslogtreecommitdiff
path: root/kernel/taskstats.c
AgeCommit message (Collapse)Author
2006-10-28[PATCH] taskstats: don't use tasklist_lockOleg Nesterov
Remove tasklist_lock from taskstats.c. find_task_by_pid() is rcu-safe. ->siglock allows us to traverse subthread without tasklist. Q: delay accounting looks wrong to me. If sub-thread has already called taskstats_exit_send() but didn't call release_task(self) yet it will be accounted twice. The window is big. No? Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-28[PATCH] taskstats: kill ->taskstats_lock in favor of ->siglockOleg Nesterov
signal_struct is (mostly) protected by ->sighand->siglock, I think we don't need ->taskstats_lock to protect ->stats. This also allows us to simplify the locking in fill_tgid(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-28[PATCH] fill_tgid: fix task_struct leak and possible oopsOleg Nesterov
1. fill_tgid() forgets to do put_task_struct(first). 2. release_task(first) can happen after fill_tgid() drops tasklist_lock, it is unsafe to dereference first->signal. This is a temporary fix, imho the locking should be reworked. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@sgi.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] csa: Extended system accounting over taskstatsJay Lan
Add extended system accounting handling over taskstats interface. A CONFIG_TASK_XACCT flag is created to enable the extended accounting code. Signed-off-by: Jay Lan <jlan@sgi.com> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Chris Sturtivant <csturtiv@sgi.com> Cc: Tony Ernst <tee@sgi.com> Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] csa: basic accounting over taskstatsJay Lan
Add some basic accounting fields to the taskstats struct, add a new kernel/tsacct.c to handle basic accounting data handling upon exit. A handle is added to taskstats.c to invoke the basic accounting data handling. Signed-off-by: Jay Lan <jlan@sgi.com> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Chris Sturtivant <csturtiv@sgi.com> Cc: Tony Ernst <tee@sgi.com> Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net> Cc: "Michal Piotrowski" <michal.k.k.piotrowski@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] Fix taskstats size calculation (use the new genetlink utility functions)Balbir Singh
The addition of the CSA patch pushed the size of struct taskstats to 256 bytes. This exposed a problem with prepare_reply(), we were not allocating space for the netlink and genetlink header. It worked earlier because alloc_skb() would align the skb to SMP_CACHE_BYTES, which added some additonal bytes. Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jamal Hadi <hadi@cyberus.ca> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Thomas Graf <tgraf@suug.ch> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-22[NETLINK]: Extend netlink messaging interfaceThomas Graf
Adds: nlmsg_get_pos() return current position in message nlmsg_trim() trim part of message nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr nla_put_nohdr(skb, len, data) add attribute w/o hdr nla_find_nested() find attribute in nested attributes Fixes nlmsg_new() to take allocation flags and consider size. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-31[PATCH] taskstats: free skb, avoid returns in send_cpu_listenersShailabh Nagar
Add a missing freeing of skb in the case there are no listeners at all. Also remove the returning of error values by the function as it is unused by the sole caller. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31[PATCH] make taskstats sending completely independent of delay accounting ↵Shailabh Nagar
on/off status Complete the separation of delay accounting and taskstats by ignoring the return value of delay accounting functions that fill in parts of taskstats before it is sent out (either in response to a command or as part of a task exit). Also make delayacct_add_tsk return silently when delay accounting is turned off rather than treat it as an error. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-15[PATCH] Remove down_write() from taskstats code invoked on the exit() pathShailabh Nagar
In send_cpu_listeners(), which is called on the exit path, a down_write() was protecting operations like skb_clone() and genlmsg_unicast() that do GFP_KERNEL allocations. If the oom-killer decides to kill tasks to satisfy the allocations,the exit of those tasks could block on the same semphore. The down_write() was only needed to allow removal of invalid listeners from the listener list. The patch converts the down_write to a down_read and defers the removal to a separate critical region. This ensures that even if the oom-killer is called, no other task's exit is blocked as it can still acquire another down_read. Thanks to Andrew Morton & Herbert Xu for pointing out the oom related pitfalls, and to Chandra Seetharaman for suggesting this fix instead of using something more complex like RCU. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-15[PATCH] per-task delay accounting taskstats interface: control exit data ↵Shailabh Nagar
through cpumasks On systems with a large number of cpus, with even a modest rate of tasks exiting per cpu, the volume of taskstats data sent on thread exit can overflow a userspace listener's buffers. One approach to avoiding overflow is to allow listeners to get data for a limited and specific set of cpus. By scaling the number of listeners and/or the cpus they monitor, userspace can handle the statistical data overload more gracefully. In this patch, each listener registers to listen to a specific set of cpus by specifying a cpumask. The interest is recorded per-cpu. When a task exits on a cpu, its taskstats data is unicast to each listener interested in that cpu. Thanks to Andrew Morton for pointing out the various scalability and general concerns of previous attempts and for suggesting this design. [akpm@osdl.org: build fix] Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-15[PATCH] delay accounting taskstats interface send tgid onceShailabh Nagar
Send per-tgid data only once during exit of a thread group instead of once with each member thread exit. Currently, when a thread exits, besides its per-tid data, the per-tgid data of its thread group is also sent out, if its thread group is non-empty. The per-tgid data sent consists of the sum of per-tid stats for all *remaining* threads of the thread group. This patch modifies this sending in two ways: - the per-tgid data is sent only when the last thread of a thread group exits. This cuts down heavily on the overhead of sending/receiving per-tgid data, especially when other exploiters of the taskstats interface aren't interested in per-tgid stats - the semantics of the per-tgid data sent are changed. Instead of being the sum of per-tid data for remaining threads, the value now sent is the true total accumalated statistics for all threads that are/were part of the thread group. The patch also addresses a minor issue where failure of one accounting subsystem to fill in the taskstats structure was causing the send of taskstats to not be sent at all. The patch has been tested for stability and run cerberus for over 4 hours on an SMP. [akpm@osdl.org: bugfixes] Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-15[PATCH] per-task-delay-accounting: delay accounting usage of taskstats interfaceShailabh Nagar
Usage of taskstats interface by delay accounting. Signed-off-by: Shailabh Nagar <nagar@us.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-15[PATCH] per-task-delay-accounting: taskstats interfaceShailabh Nagar
Create a "taskstats" interface based on generic netlink (NETLINK_GENERIC family), for getting statistics of tasks and thread groups during their lifetime and when they exit. The interface is intended for use by multiple accounting packages though it is being created in the context of delay accounting. This patch creates the interface without populating the fields of the data that is sent to the user in response to a command or upon the exit of a task. Each accounting package interested in using taskstats has to provide an additional patch to add its stats to the common structure. [akpm@osdl.org: cleanups, Kconfig fix] Signed-off-by: Shailabh Nagar <nagar@us.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>