The patch titled
futex_find_get_task(): don't take tasklist_lock
has been removed from the -mm tree. Its filename is
futex_find_get_task-dont-take-tasklist_lock.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: futex_find_get_task(): don't take tasklist_lock
From: Oleg Nesterov <oleg@xxxxxxxxxx>
It is ok to do find_task_by_pid() + get_task_struct() under
rcu_read_lock(), we cand drop tasklist_lock.
Note that testing of ->exit_state is racy with or without tasklist anyway.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/futex.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN kernel/futex.c~futex_find_get_task-dont-take-tasklist_lock kernel/futex.c
--- a/kernel/futex.c~futex_find_get_task-dont-take-tasklist_lock
+++ a/kernel/futex.c
@@ -389,7 +389,7 @@ static struct task_struct * futex_find_g
{
struct task_struct *p;
- read_lock(&tasklist_lock);
+ rcu_read_lock();
p = find_task_by_pid(pid);
if (!p)
goto out_unlock;
@@ -403,7 +403,7 @@ static struct task_struct * futex_find_g
}
get_task_struct(p);
out_unlock:
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
return p;
}
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
git-block.patch
proc-readdir-race-fix-take-3-race-fix.patch
vt-rework-the-console-spawning-variables.patch
vt-make-vt_pid-a-struct-pid-making-it-pid-wrap-around-safe.patch
simplify-pid-iterators.patch
file-add-locking-to-f_getown.patch
proc-convert-task_sig-to-use-lock_task_sighand.patch
proc-convert-do_task_stat-to-use-lock_task_sighand.patch
proc-drop-tasklist-lock-in-task_state.patch
proc-properly-compute-tgid_offset.patch
proc-remove-trailing-blank-entry-from-pid_entry-arrays.patch
proc-remove-the-useless-smp-safe-comments-from-proc.patch
proc-comment-what-proc_fill_cache-does.patch
introduce-get_task_pid-to-fix-unsafe-get_pid.patch
rcu-simplify-improve-batch-tuning.patch
pidhash-temporary-debug-checks.patch
-
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