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  1. 18 8月, 2010 1 次提交
    • N
      fs: fs_struct rwlock to spinlock · 2a4419b5
      由 Nick Piggin 提交于 
      fs: fs_struct rwlock to spinlock

struct fs_struct.lock is an rwlock with the read-side used to protect root and
pwd members while taking references to them. Taking a reference to a path
typically requires just 2 atomic ops, so the critical section is very small.
Parallel read-side operations would have cacheline contention on the lock, the
dentry, and the vfsmount cachelines, so the rwlock is unlikely to ever give a
real parallelism increase.

Replace it with a spinlock to avoid one or two atomic operations in typical
path lookup fastpath.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      2a4419b5
  3. 28 7月, 2010 1 次提交
    • E
      fsnotify: pass a file instead of an inode to open, read, and write · 2a12a9d7
      由 Eric Paris 提交于 
      fanotify, the upcoming notification system actually needs a struct path so it can
do opens in the context of listeners, and it needs a file so it can get f_flags
from the original process.  Close was the only operation that already was passing
a struct file to the notification hook.  This patch passes a file for access,
modify, and open as well as they are easily available to these hooks.
Signed-off-by: NEric Paris <eparis@redhat.com>
      2a12a9d7
  5. 10 7月, 2010 1 次提交
  7. 09 6月, 2010 1 次提交
  9. 28 5月, 2010 6 次提交
  11. 25 5月, 2010 1 次提交
    • M
      mm: migration: avoid race between shift_arg_pages() and rmap_walk() during... · a8bef8ff
      由 Mel Gorman 提交于 
      mm: migration: avoid race between shift_arg_pages() and rmap_walk() during migration by not migrating temporary stacks

Page migration requires rmap to be able to find all ptes mapping a page
at all times, otherwise the migration entry can be instantiated, but it
is possible to leave one behind if the second rmap_walk fails to find
the page.  If this page is later faulted, migration_entry_to_page() will
call BUG because the page is locked indicating the page was migrated by
the migration PTE not cleaned up. For example

  kernel BUG at include/linux/swapops.h:105!
  invalid opcode: 0000 [#1] PREEMPT SMP
  ...
  Call Trace:
   [<ffffffff810e951a>] handle_mm_fault+0x3f8/0x76a
   [<ffffffff8130c7a2>] do_page_fault+0x44a/0x46e
   [<ffffffff813099b5>] page_fault+0x25/0x30
   [<ffffffff8114de33>] load_elf_binary+0x152a/0x192b
   [<ffffffff8111329b>] search_binary_handler+0x173/0x313
   [<ffffffff81114896>] do_execve+0x219/0x30a
   [<ffffffff8100a5c6>] sys_execve+0x43/0x5e
   [<ffffffff8100320a>] stub_execve+0x6a/0xc0
  RIP  [<ffffffff811094ff>] migration_entry_wait+0xc1/0x129

There is a race between shift_arg_pages and migration that triggers this
bug.  A temporary stack is setup during exec and later moved.  If
migration moves a page in the temporary stack and the VMA is then removed
before migration completes, the migration PTE may not be found leading to
a BUG when the stack is faulted.

This patch causes pages within the temporary stack during exec to be
skipped by migration.  It does this by marking the VMA covering the
temporary stack with an otherwise impossible combination of VMA flags.
These flags are cleared when the temporary stack is moved to its final
location.

[kamezawa.hiroyu@jp.fujitsu.com: idea for having migration skip temporary stacks]
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a8bef8ff
  13. 12 5月, 2010 1 次提交
    • R
      revert "procfs: provide stack information for threads" and its fixup commits · 34441427
      由 Robin Holt 提交于 
      Originally, commit d899bf7b ("procfs: provide stack information for
threads") attempted to introduce a new feature for showing where the
threadstack was located and how many pages are being utilized by the
stack.

Commit c44972f1 ("procfs: disable per-task stack usage on NOMMU") was
applied to fix the NO_MMU case.

Commit 89240ba0 ("x86, fs: Fix x86 procfs stack information for threads on
64-bit") was applied to fix a bug in ia32 executables being loaded.

Commit 9ebd4eba ("procfs: fix /proc/<pid>/stat stack pointer for kernel
threads") was applied to fix a bug which had kernel threads printing a
userland stack address.

Commit 1306d603 ('proc: partially revert "procfs: provide stack
information for threads"') was then applied to revert the stack pages
being used to solve a significant performance regression.

This patch nearly undoes the effect of all these patches.

The reason for reverting these is it provides an unusable value in
field 28.  For x86_64, a fork will result in the task->stack_start
value being updated to the current user top of stack and not the stack
start address.  This unpredictability of the stack_start value makes
it worthless.  That includes the intended use of showing how much stack
space a thread has.

Other architectures will get different values.  As an example, ia64
gets 0.  The do_fork() and copy_process() functions appear to treat the
stack_start and stack_size parameters as architecture specific.

I only partially reverted c44972f1 ("procfs: disable per-task stack usage
on NOMMU") .  If I had completely reverted it, I would have had to change
mm/Makefile only build pagewalk.o when CONFIG_PROC_PAGE_MONITOR is
configured.  Since I could not test the builds without significant effort,
I decided to not change mm/Makefile.

I only partially reverted 89240ba0 ("x86, fs: Fix x86 procfs stack
information for threads on 64-bit") .  I left the KSTK_ESP() change in
place as that seemed worthwhile.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      34441427
  15. 07 3月, 2010 7 次提交
    • N
      coredump: suppress uid comparison test if core output files are pipes · 76595f79
      由 Neil Horman 提交于 
      Modify uid check in do_coredump so as to not apply it in the case of
pipes.

This just got noticed in testing.  The end of do_coredump validates the
uid of the inode for the created file against the uid of the crashing
process to ensure that no one can pre-create a core file with different
ownership and grab the information contained in the core when they
shouldn' tbe able to.  This causes failures when using pipes for a core
dumps if the crashing process is not root, which is the uid of the pipe
when it is created.

The fix is simple.  Since the check for matching uid's isn't relevant for
pipes (a process can't create a pipe that the uermodehelper code will open
anyway), we can just just skip it in the event ispipe is non-zero

Reverts a pipe-affecting change which was accidentally made in

: commit c46f739d
: Author:     Ingo Molnar <mingo@elte.hu>
: AuthorDate: Wed Nov 28 13:59:18 2007 +0100
: Commit:     Linus Torvalds <torvalds@woody.linux-foundation.org>
: CommitDate: Wed Nov 28 10:58:01 2007 -0800
:
:     vfs: coredumping fix
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      76595f79
    • O
      coredump: set ->group_exit_code for other CLONE_VM tasks too · 5c99cbf4
      由 Oleg Nesterov 提交于 
      User visible change.

do_coredump() kills all threads which share the same ->mm but only the
coredumping process gets the proper exit_code.  Other tasks which share
the same ->mm die "silently" and return status == 0 to parent.

This is historical behaviour, not actually a bug.  But I think Frank
Heckenbach rightly dislikes the current behaviour.  Simple test-case:

	#include <stdio.h>
	#include <unistd.h>
	#include <signal.h>
	#include <sys/wait.h>

	int main(void)
	{
		int stat;

		if (!fork()) {
			if (!vfork())
				kill(getpid(), SIGQUIT);
		}

		wait(&stat);
		printf("stat=%x\n", stat);
		return 0;
	}

Before this patch it prints "stat=0" despite the fact the child was killed
by SIGQUIT.  After this patch the output is "stat=3" which obviously makes
more sense.

Even with this patch, only the task which originates the coredumping gets
"|= 0x80" if the core was actually dumped, but at least the coredumping
signal is visible to do_wait/etc.
Reported-by: NFrank Heckenbach <f.heckenbach@fh-soft.de>
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NWANG Cong <xiyou.wangcong@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5c99cbf4
    • M
      coredump: pass mm->flags as a coredump parameter for consistency · 30736a4d
      由 Masami Hiramatsu 提交于 
      Pass mm->flags as a coredump parameter for consistency.

 ---
1787         if (mm->core_state || !get_dumpable(mm)) {  <- (1)
1788                 up_write(&mm->mmap_sem);
1789                 put_cred(cred);
1790                 goto fail;
1791         }
1792
[...]
1798         if (get_dumpable(mm) == 2) {    /* Setuid core dump mode */ <-(2)
1799                 flag = O_EXCL;          /* Stop rewrite attacks */
1800                 cred->fsuid = 0;        /* Dump root private */
1801         }
 ---

Since dumpable bits are not protected by lock, there is a chance to change
these bits between (1) and (2).

To solve this issue, this patch copies mm->flags to
coredump_params.mm_flags at the beginning of do_coredump() and uses it
instead of get_dumpable() while dumping core.

This copy is also passed to binfmt->core_dump, since elf*_core_dump() uses
dump_filter bits in mm->flags.

[akpm@linux-foundation.org: fix merge]
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Acked-by: NRoland McGrath <roland@redhat.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      30736a4d
    • M
      exec: create initial stack independent of PAGE_SIZE · 5ef097dd
      由 Michael Neuling 提交于 
      Currently we create the initial stack based on the PAGE_SIZE.  This is
unnecessary.

This creates this initial stack independent of the PAGE_SIZE.

It also bumps up the number of 4k pages allocated from 20 to 32, to
align with 64K page systems.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Cc: Helge Deller <deller@gmx.de>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5ef097dd
    • J
      fs: use rlimit helpers · d554ed89
      由 Jiri Slaby 提交于 
      Make sure compiler won't do weird things with limits.  E.g.  fetching them
twice may return 2 different values after writable limits are implemented.

I.e.  either use rlimit helpers added in commit 3e10e716 ("resource:
add helpers for fetching rlimits") or ACCESS_ONCE if not applicable.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d554ed89
    • R
      mm: change anon_vma linking to fix multi-process server scalability issue · 5beb4930
      由 Rik van Riel 提交于 
      The old anon_vma code can lead to scalability issues with heavily forking
workloads.  Specifically, each anon_vma will be shared between the parent
process and all its child processes.

In a workload with 1000 child processes and a VMA with 1000 anonymous
pages per process that get COWed, this leads to a system with a million
anonymous pages in the same anon_vma, each of which is mapped in just one
of the 1000 processes.  However, the current rmap code needs to walk them
all, leading to O(N) scanning complexity for each page.

This can result in systems where one CPU is walking the page tables of
1000 processes in page_referenced_one, while all other CPUs are stuck on
the anon_vma lock.  This leads to catastrophic failure for a benchmark
like AIM7, where the total number of processes can reach in the tens of
thousands.  Real workloads are still a factor 10 less process intensive
than AIM7, but they are catching up.

This patch changes the way anon_vmas and VMAs are linked, which allows us
to associate multiple anon_vmas with a VMA.  At fork time, each child
process gets its own anon_vmas, in which its COWed pages will be
instantiated.  The parents' anon_vma is also linked to the VMA, because
non-COWed pages could be present in any of the children.

This reduces rmap scanning complexity to O(1) for the pages of the 1000
child processes, with O(N) complexity for at most 1/N pages in the system.
 This reduces the average scanning cost in heavily forking workloads from
O(N) to 2.

The only real complexity in this patch stems from the fact that linking a
VMA to anon_vmas now involves memory allocations.  This means vma_adjust
can fail, if it needs to attach a VMA to anon_vma structures.  This in
turn means error handling needs to be added to the calling functions.

A second source of complexity is that, because there can be multiple
anon_vmas, the anon_vma linking in vma_adjust can no longer be done under
"the" anon_vma lock.  To prevent the rmap code from walking up an
incomplete VMA, this patch introduces the VM_LOCK_RMAP VMA flag.  This bit
flag uses the same slot as the NOMMU VM_MAPPED_COPY, with an ifdef in mm.h
to make sure it is impossible to compile a kernel that needs both symbolic
values for the same bitflag.

Some test results:

Without the anon_vma changes, when AIM7 hits around 9.7k users (on a test
box with 16GB RAM and not quite enough IO), the system ends up running
>99% in system time, with every CPU on the same anon_vma lock in the
pageout code.

With these changes, AIM7 hits the cross-over point around 29.7k users.
This happens with ~99% IO wait time, there never seems to be any spike in
system time.  The anon_vma lock contention appears to be resolved.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: NRik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5beb4930
    • K
      mm: avoid false sharing of mm_counter · 34e55232
      由 KAMEZAWA Hiroyuki 提交于 
      Considering the nature of per mm stats, it's the shared object among
threads and can be a cache-miss point in the page fault path.

This patch adds per-thread cache for mm_counter.  RSS value will be
counted into a struct in task_struct and synchronized with mm's one at
events.

Now, in this patch, the event is the number of calls to handle_mm_fault.
Per-thread value is added to mm at each 64 calls.

 rough estimation with small benchmark on parallel thread (2threads) shows
 [before]
     4.5 cache-miss/faults
 [after]
     4.0 cache-miss/faults
 Anyway, the most contended object is mmap_sem if the number of threads grows.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      34e55232
  17. 23 2月, 2010 1 次提交
  19. 12 2月, 2010 1 次提交
    • M
      fs/exec.c: restrict initial stack space expansion to rlimit · 803bf5ec
      由 Michael Neuling 提交于 
      When reserving stack space for a new process, make sure we're not
attempting to expand the stack by more than rlimit allows.

This fixes a bug caused by b6a2fea3 ("mm:
variable length argument support") and unmasked by
fc63cf23 ("exec: setup_arg_pages() fails
to return errors").

This bug means that when limiting the stack to less the 20*PAGE_SIZE (eg.
80K on 4K pages or 'ulimit -s 79') all processes will be killed before
they start.  This is particularly bad with 64K pages, where a ulimit below
1280K will kill every process.

To test, do:

  'ulimit -s 15; ls'

before and after the patch is applied.  Before it's applied, 'ls' should
be killed.  After the patch is applied, 'ls' should no longer be killed.

A stack limit of 15KB since it's small enough to trigger 20*PAGE_SIZE.
Also 15KB not a multiple of PAGE_SIZE, which is a trickier case to handle
correctly with this code.

4K pages should be fine to test with.

[kosaki.motohiro@jp.fujitsu.com: cleanup]
[akpm@linux-foundation.org: cleanup cleanup]
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      803bf5ec
  21. 03 2月, 2010 1 次提交
    • L
      Fix 'flush_old_exec()/setup_new_exec()' split · 7ab02af4
      由 Linus Torvalds 提交于 
      Commit 221af7f8 ("Split 'flush_old_exec' into two functions") split
the function at the point of no return - ie right where there were no
more error cases to check.  That made sense from a technical standpoint,
but when we then also combined it with the actual personality setting
going in between flush_old_exec() and setup_new_exec(), it needs to be a
bit more careful.

In particular, we need to make sure that we really flush the old
personality bits in the 'flush' stage, rather than later in the 'setup'
stage, since otherwise we might be flushing the _new_ personality state
that we're just setting up.

So this moves the flags and personality flushing (and 'flush_thread()',
which is the arch-specific function that generally resets lazy FP state
etc) of the old process into flush_old_exec(), so that it doesn't affect
any state that execve() is setting up for the new process environment.

This was reported by Michal Simek as breaking his Microblaze qemu
environment.
Reported-and-tested-by: NMichal Simek <michal.simek@petalogix.com>
Cc: Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7ab02af4
  23. 30 1月, 2010 1 次提交
    • L
      Split 'flush_old_exec' into two functions · 221af7f8
      由 Linus Torvalds 提交于 
      'flush_old_exec()' is the point of no return when doing an execve(), and
it is pretty badly misnamed.  It doesn't just flush the old executable
environment, it also starts up the new one.

Which is very inconvenient for things like setting up the new
personality, because we want the new personality to affect the starting
of the new environment, but at the same time we do _not_ want the new
personality to take effect if flushing the old one fails.

As a result, the x86-64 '32-bit' personality is actually done using this
insane "I'm going to change the ABI, but I haven't done it yet" bit
(TIF_ABI_PENDING), with SET_PERSONALITY() not actually setting the
personality, but just the "pending" bit, so that "flush_thread()" can do
the actual personality magic.

This patch in no way changes any of that insanity, but it does split the
'flush_old_exec()' function up into a preparatory part that can fail
(still called flush_old_exec()), and a new part that will actually set
up the new exec environment (setup_new_exec()).  All callers are changed
to trivially comply with the new world order.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      221af7f8
  25. 18 12月, 2009 2 次提交
  27. 16 12月, 2009 1 次提交
    • J
      procfs: allow threads to rename siblings via /proc/pid/tasks/tid/comm · 4614a696
      由 john stultz 提交于 
      Setting a thread's comm to be something unique is a very useful ability
and is helpful for debugging complicated threaded applications.  However
currently the only way to set a thread name is for the thread to name
itself via the PR_SET_NAME prctl.

However, there may be situations where it would be advantageous for a
thread dispatcher to be naming the threads its managing, rather then
having the threads self-describe themselves.  This sort of behavior is
available on other systems via the pthread_setname_np() interface.

This patch exports a task's comm via proc/pid/comm and
proc/pid/task/tid/comm interfaces, and allows thread siblings to write to
these values.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Mike Fulton <fultonm@ca.ibm.com>
Cc: Sean Foley <Sean_Foley@ca.ibm.com>
Cc: Darren Hart <dvhltc@us.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4614a696
  29. 12 11月, 2009 1 次提交
  31. 25 10月, 2009 1 次提交
  33. 24 9月, 2009 5 次提交
  35. 23 9月, 2009 2 次提交
    • S
      procfs: provide stack information for threads · d899bf7b
      由 Stefani Seibold 提交于 
      A patch to give a better overview of the userland application stack usage,
especially for embedded linux.

Currently you are only able to dump the main process/thread stack usage
which is showed in /proc/pid/status by the "VmStk" Value.  But you get no
information about the consumed stack memory of the the threads.

There is an enhancement in the /proc/<pid>/{task/*,}/*maps and which marks
the vm mapping where the thread stack pointer reside with "[thread stack
xxxxxxxx]".  xxxxxxxx is the maximum size of stack.  This is a value
information, because libpthread doesn't set the start of the stack to the
top of the mapped area, depending of the pthread usage.

A sample output of /proc/<pid>/task/<tid>/maps looks like:

08048000-08049000 r-xp 00000000 03:00 8312       /opt/z
08049000-0804a000 rw-p 00001000 03:00 8312       /opt/z
0804a000-0806b000 rw-p 00000000 00:00 0          [heap]
a7d12000-a7d13000 ---p 00000000 00:00 0
a7d13000-a7f13000 rw-p 00000000 00:00 0          [thread stack: 001ff4b4]
a7f13000-a7f14000 ---p 00000000 00:00 0
a7f14000-a7f36000 rw-p 00000000 00:00 0
a7f36000-a8069000 r-xp 00000000 03:00 4222       /lib/libc.so.6
a8069000-a806b000 r--p 00133000 03:00 4222       /lib/libc.so.6
a806b000-a806c000 rw-p 00135000 03:00 4222       /lib/libc.so.6
a806c000-a806f000 rw-p 00000000 00:00 0
a806f000-a8083000 r-xp 00000000 03:00 14462      /lib/libpthread.so.0
a8083000-a8084000 r--p 00013000 03:00 14462      /lib/libpthread.so.0
a8084000-a8085000 rw-p 00014000 03:00 14462      /lib/libpthread.so.0
a8085000-a8088000 rw-p 00000000 00:00 0
a8088000-a80a4000 r-xp 00000000 03:00 8317       /lib/ld-linux.so.2
a80a4000-a80a5000 r--p 0001b000 03:00 8317       /lib/ld-linux.so.2
a80a5000-a80a6000 rw-p 0001c000 03:00 8317       /lib/ld-linux.so.2
afaf5000-afb0a000 rw-p 00000000 00:00 0          [stack]
ffffe000-fffff000 r-xp 00000000 00:00 0          [vdso]

Also there is a new entry "stack usage" in /proc/<pid>/{task/*,}/status
which will you give the current stack usage in kb.

A sample output of /proc/self/status looks like:

Name:	cat
State:	R (running)
Tgid:	507
Pid:	507
.
.
.
CapBnd:	fffffffffffffeff
voluntary_ctxt_switches:	0
nonvoluntary_ctxt_switches:	0
Stack usage:	12 kB

I also fixed stack base address in /proc/<pid>/{task/*,}/stat to the base
address of the associated thread stack and not the one of the main
process.  This makes more sense.

[akpm@linux-foundation.org: fs/proc/array.c now needs walk_page_range()]
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d899bf7b
    • J
      getrusage: fill ru_maxrss value · 1f10206c
      由 Jiri Pirko 提交于 
      Make ->ru_maxrss value in struct rusage filled accordingly to rss hiwater
mark.  This struct is filled as a parameter to getrusage syscall.
->ru_maxrss value is set to KBs which is the way it is done in BSD
systems.  /usr/bin/time (gnu time) application converts ->ru_maxrss to KBs
which seems to be incorrect behavior.  Maintainer of this util was
notified by me with the patch which corrects it and cc'ed.

To make this happen we extend struct signal_struct by two fields.  The
first one is ->maxrss which we use to store rss hiwater of the task.  The
second one is ->cmaxrss which we use to store highest rss hiwater of all
task childs.  These values are used in k_getrusage() to actually fill
->ru_maxrss.  k_getrusage() uses current rss hiwater value directly if mm
struct exists.

Note:
exec() clear mm->hiwater_rss, but doesn't clear sig->maxrss.
it is intetionally behavior. *BSD getrusage have exec() inheriting.

test programs
========================================================

getrusage.c
===========
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <signal.h>
 #include <sys/mman.h>

 #include "common.h"

 #define err(str) perror(str), exit(1)

int main(int argc, char** argv)
{
	int status;

	printf("allocate 100MB\n");
	consume(100);

	printf("testcase1: fork inherit? \n");
	printf("  expect: initial.self ~= child.self\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&status);
	} else {
		show_rusage("fork child");
		_exit(0);
	}
	printf("\n");

	printf("testcase2: fork inherit? (cont.) \n");
	printf("  expect: initial.children ~= 100MB, but child.children = 0\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&status);
	} else {
		show_rusage("child");
		_exit(0);
	}
	printf("\n");

	printf("testcase3: fork + malloc \n");
	printf("  expect: child.self ~= initial.self + 50MB\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&status);
	} else {
		printf("allocate +50MB\n");
		consume(50);
		show_rusage("fork child");
		_exit(0);
	}
	printf("\n");

	printf("testcase4: grandchild maxrss\n");
	printf("  expect: post_wait.children ~= 300MB\n");
	show_rusage("initial");
	if (__fork()) {
		wait(&status);
		show_rusage("post_wait");
	} else {
		system("./child -n 0 -g 300");
		_exit(0);
	}
	printf("\n");

	printf("testcase5: zombie\n");
	printf("  expect: pre_wait ~= initial, IOW the zombie process is not accounted.\n");
	printf("          post_wait ~= 400MB, IOW wait() collect child's max_rss. \n");
	show_rusage("initial");
	if (__fork()) {
		sleep(1); /* children become zombie */
		show_rusage("pre_wait");
		wait(&status);
		show_rusage("post_wait");
	} else {
		system("./child -n 400");
		_exit(0);
	}
	printf("\n");

	printf("testcase6: SIG_IGN\n");
	printf("  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).\n");
	show_rusage("initial");
	signal(SIGCHLD, SIG_IGN);
	if (__fork()) {
		sleep(1); /* children become zombie */
		show_rusage("after_zombie");
	} else {
		system("./child -n 500");
		_exit(0);
	}
	printf("\n");
	signal(SIGCHLD, SIG_DFL);

	printf("testcase7: exec (without fork) \n");
	printf("  expect: initial ~= exec \n");
	show_rusage("initial");
	execl("./child", "child", "-v", NULL);

	return 0;
}

child.c
=======
 #include <sys/types.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <sys/resource.h>

 #include "common.h"

int main(int argc, char** argv)
{
	int status;
	int c;
	long consume_size = 0;
	long grandchild_consume_size = 0;
	int show = 0;

	while ((c = getopt(argc, argv, "n:g:v")) != -1) {
		switch (c) {
		case 'n':
			consume_size = atol(optarg);
			break;
		case 'v':
			show = 1;
			break;
		case 'g':

			grandchild_consume_size = atol(optarg);
			break;
		default:
			break;
		}
	}

	if (show)
		show_rusage("exec");

	if (consume_size) {
		printf("child alloc %ldMB\n", consume_size);
		consume(consume_size);
	}

	if (grandchild_consume_size) {
		if (fork()) {
			wait(&status);
		} else {
			printf("grandchild alloc %ldMB\n", grandchild_consume_size);
			consume(grandchild_consume_size);

			exit(0);
		}
	}

	return 0;
}

common.c
========
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <signal.h>
 #include <sys/mman.h>

 #include "common.h"
 #define err(str) perror(str), exit(1)

void show_rusage(char *prefix)
{
    	int err, err2;
    	struct rusage rusage_self;
    	struct rusage rusage_children;

    	printf("%s: ", prefix);
    	err = getrusage(RUSAGE_SELF, &rusage_self);
    	if (!err)
    		printf("self %ld ", rusage_self.ru_maxrss);
    	err2 = getrusage(RUSAGE_CHILDREN, &rusage_children);
    	if (!err2)
    		printf("children %ld ", rusage_children.ru_maxrss);

    	printf("\n");
}

/* Some buggy OS need this worthless CPU waste. */
void make_pagefault(void)
{
	void *addr;
	int size = getpagesize();
	int i;

	for (i=0; i<1000; i++) {
		addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
		if (addr == MAP_FAILED)
			err("make_pagefault");
		memset(addr, 0, size);
		munmap(addr, size);
	}
}

void consume(int mega)
{
    	size_t sz = mega * 1024 * 1024;
    	void *ptr;

    	ptr = malloc(sz);
    	memset(ptr, 0, sz);
	make_pagefault();
}

pid_t __fork(void)
{
	pid_t pid;

	pid = fork();
	make_pagefault();

	return pid;
}

common.h
========
void show_rusage(char *prefix);
void make_pagefault(void);
void consume(int mega);
pid_t __fork(void);

FreeBSD result (expected result)
========================================================
allocate 100MB
testcase1: fork inherit?
  expect: initial.self ~= child.self
initial: self 103492 children 0
fork child: self 103540 children 0

testcase2: fork inherit? (cont.)
  expect: initial.children ~= 100MB, but child.children = 0
initial: self 103540 children 103540
child: self 103564 children 0

testcase3: fork + malloc
  expect: child.self ~= initial.self + 50MB
initial: self 103564 children 103564
allocate +50MB
fork child: self 154860 children 0

testcase4: grandchild maxrss
  expect: post_wait.children ~= 300MB
initial: self 103564 children 154860
grandchild alloc 300MB
post_wait: self 103564 children 308720

testcase5: zombie
  expect: pre_wait ~= initial, IOW the zombie process is not accounted.
          post_wait ~= 400MB, IOW wait() collect child's max_rss.
initial: self 103564 children 308720
child alloc 400MB
pre_wait: self 103564 children 308720
post_wait: self 103564 children 411312

testcase6: SIG_IGN
  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).
initial: self 103564 children 411312
child alloc 500MB
after_zombie: self 103624 children 411312

testcase7: exec (without fork)
  expect: initial ~= exec
initial: self 103624 children 411312
exec: self 103624 children 411312

Linux result (actual test result)
========================================================
allocate 100MB
testcase1: fork inherit?
  expect: initial.self ~= child.self
initial: self 102848 children 0
fork child: self 102572 children 0

testcase2: fork inherit? (cont.)
  expect: initial.children ~= 100MB, but child.children = 0
initial: self 102876 children 102644
child: self 102572 children 0

testcase3: fork + malloc
  expect: child.self ~= initial.self + 50MB
initial: self 102876 children 102644
allocate +50MB
fork child: self 153804 children 0

testcase4: grandchild maxrss
  expect: post_wait.children ~= 300MB
initial: self 102876 children 153864
grandchild alloc 300MB
post_wait: self 102876 children 307536

testcase5: zombie
  expect: pre_wait ~= initial, IOW the zombie process is not accounted.
          post_wait ~= 400MB, IOW wait() collect child's max_rss.
initial: self 102876 children 307536
child alloc 400MB
pre_wait: self 102876 children 307536
post_wait: self 102876 children 410076

testcase6: SIG_IGN
  expect: initial ~= after_zombie (child's 500MB alloc should be ignored).
initial: self 102876 children 410076
child alloc 500MB
after_zombie: self 102880 children 410076

testcase7: exec (without fork)
  expect: initial ~= exec
initial: self 102880 children 410076
exec: self 102880 children 410076
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1f10206c
  37. 21 9月, 2009 1 次提交
    • I
      perf: Do the big rename: Performance Counters -> Performance Events · cdd6c482
      由 Ingo Molnar 提交于 
      Bye-bye Performance Counters, welcome Performance Events!

In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.

Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.

All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)

The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.

Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.

User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)

This patch has been generated via the following script:

  FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

  sed -i \
    -e 's/PERF_EVENT_/PERF_RECORD_/g' \
    -e 's/PERF_COUNTER/PERF_EVENT/g' \
    -e 's/perf_counter/perf_event/g' \
    -e 's/nb_counters/nb_events/g' \
    -e 's/swcounter/swevent/g' \
    -e 's/tpcounter_event/tp_event/g' \
    $FILES

  for N in $(find . -name perf_counter.[ch]); do
    M=$(echo $N | sed 's/perf_counter/perf_event/g')
    mv $N $M
  done

  FILES=$(find . -name perf_event.*)

  sed -i \
    -e 's/COUNTER_MASK/REG_MASK/g' \
    -e 's/COUNTER/EVENT/g' \
    -e 's/\<event\>/event_id/g' \
    -e 's/counter/event/g' \
    -e 's/Counter/Event/g' \
    $FILES

... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.

Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.

( NOTE: 'counters' are still the proper terminology when we deal
  with hardware registers - and these sed scripts are a bit
  over-eager in renaming them. I've undone some of that, but
  in case there's something left where 'counter' would be
  better than 'event' we can undo that on an individual basis
  instead of touching an otherwise nicely automated patch. )
Suggested-by: NStephane Eranian <eranian@google.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NPaul Mackerras <paulus@samba.org>
Reviewed-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      cdd6c482
  39. 06 9月, 2009 1 次提交
    • O
      exec: do not sleep in TASK_TRACED under ->cred_guard_mutex · a2a8474c
      由 Oleg Nesterov 提交于 
      Tom Horsley reports that his debugger hangs when it tries to read
/proc/pid_of_tracee/maps, this happens since

	"mm_for_maps: take ->cred_guard_mutex to fix the race with exec"
	04b836cbf19e885f8366bccb2e4b0474346c02d

commit in 2.6.31.

But the root of the problem lies in the fact that do_execve() path calls
tracehook_report_exec() which can stop if the tracer sets PT_TRACE_EXEC.

The tracee must not sleep in TASK_TRACED holding this mutex.  Even if we
remove ->cred_guard_mutex from mm_for_maps() and proc_pid_attr_write(),
another task doing PTRACE_ATTACH should not hang until it is killed or the
tracee resumes.

With this patch do_execve() does not use ->cred_guard_mutex directly and
we do not hold it throughout, instead:

	- introduce prepare_bprm_creds() helper, it locks the mutex
	  and calls prepare_exec_creds() to initialize bprm->cred.

	- install_exec_creds() drops the mutex after commit_creds(),
	  and thus before tracehook_report_exec()->ptrace_stop().

	  or, if exec fails,

	  free_bprm() drops this mutex when bprm->cred != NULL which
	  indicates install_exec_creds() was not called.
Reported-by: NTom Horsley <tom.horsley@att.net>
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a2a8474c
  41. 24 8月, 2009 1 次提交
  43. 07 7月, 2009 1 次提交
  45. 22 5月, 2009 1 次提交