diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-07 17:54:07 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-07 17:54:07 -0700 |
commit | 48d212a2eecaca2e1875925837ad27b2f43f48a3 (patch) | |
tree | fbd83c7b15856971f6d7297e1d23dc862ba2989c /arch/x86/kernel/cpu/perf_event.c | |
parent | 46edaedaf3842164281d0f86c41bc152f4b4d32e (diff) |
Revert "mm: correctly synchronize rss-counters at exit/exec"
This reverts commit 40af1bbdca47e5c8a2044039bb78ca8fd8b20f94.
It's horribly and utterly broken for at least the following reasons:
- calling sync_mm_rss() from mmput() is fundamentally wrong, because
there's absolutely no reason to believe that the task that does the
mmput() always does it on its own VM. Example: fork, ptrace, /proc -
you name it.
- calling it *after* having done mmdrop() on it is doubly insane, since
the mm struct may well be gone now.
- testing mm against NULL before you call it is insane too, since a
NULL mm there would have caused oopses long before.
.. and those are just the three bugs I found before I decided to give up
looking for me and revert it asap. I should have caught it before I
even took it, but I trusted Andrew too much.
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
0 files changed, 0 insertions, 0 deletions