diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2014-02-19 11:56:06 +0100 |
|---|---|---|
| committer | Gary S. Robertson <gary.robertson@linaro.org> | 2014-05-07 08:56:21 -0500 |
| commit | 0a4eb2e367b825b2b0f4dcfe9ea4d0ac13e2d8d8 (patch) | |
| tree | 19ccf95f7fc5703534d2c673f9c2e017d3254e11 | |
| parent | b2c5314867bb7b62c45ffb3d1a3b9103d814c50c (diff) | |
kernel/hrtimer: be non-freezeable in cpu_chill()
Since we replaced msleep() by hrtimer I see now and then (rarely) this:
| [....] Waiting for /dev to be fully populated...
| =====================================
| [ BUG: udevd/229 still has locks held! ]
| 3.12.11-rt17 #23 Not tainted
| -------------------------------------
| 1 lock held by udevd/229:
| #0: (&type->i_mutex_dir_key#2){+.+.+.}, at: lookup_slow+0x28/0x98
|
| stack backtrace:
| CPU: 0 PID: 229 Comm: udevd Not tainted 3.12.11-rt17 #23
| (unwind_backtrace+0x0/0xf8) from (show_stack+0x10/0x14)
| (show_stack+0x10/0x14) from (dump_stack+0x74/0xbc)
| (dump_stack+0x74/0xbc) from (do_nanosleep+0x120/0x160)
| (do_nanosleep+0x120/0x160) from (hrtimer_nanosleep+0x90/0x110)
| (hrtimer_nanosleep+0x90/0x110) from (cpu_chill+0x30/0x38)
| (cpu_chill+0x30/0x38) from (dentry_kill+0x158/0x1ec)
| (dentry_kill+0x158/0x1ec) from (dput+0x74/0x15c)
| (dput+0x74/0x15c) from (lookup_real+0x4c/0x50)
| (lookup_real+0x4c/0x50) from (__lookup_hash+0x34/0x44)
| (__lookup_hash+0x34/0x44) from (lookup_slow+0x38/0x98)
| (lookup_slow+0x38/0x98) from (path_lookupat+0x208/0x7fc)
| (path_lookupat+0x208/0x7fc) from (filename_lookup+0x20/0x60)
| (filename_lookup+0x20/0x60) from (user_path_at_empty+0x50/0x7c)
| (user_path_at_empty+0x50/0x7c) from (user_path_at+0x14/0x1c)
| (user_path_at+0x14/0x1c) from (vfs_fstatat+0x48/0x94)
| (vfs_fstatat+0x48/0x94) from (SyS_stat64+0x14/0x30)
| (SyS_stat64+0x14/0x30) from (ret_fast_syscall+0x0/0x48)
For now I see no better way but to disable the freezer the sleep the period.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | kernel/hrtimer.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index b569c6d99f38..eb4c8831ccf4 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1896,8 +1896,12 @@ void cpu_chill(void) struct timespec tu = { .tv_nsec = NSEC_PER_MSEC, }; + unsigned int freeze_flag = current->flags & PF_NOFREEZE; + current->flags |= PF_NOFREEZE; hrtimer_nanosleep(&tu, NULL, HRTIMER_MODE_REL, CLOCK_MONOTONIC); + if (!freeze_flag) + current->flags &= ~PF_NOFREEZE; } EXPORT_SYMBOL(cpu_chill); #endif |