diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2011-10-20 15:14:25 +0200 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2011-10-20 15:14:25 +0200 |
| commit | b4cbb8a4e602ea77b0525d06eff89c6a6070dab3 (patch) | |
| tree | a5dd723679582505ef3905c90f0c2c032d191b94 /mm/backing-dev.c | |
| parent | 526b264163068f77c5f2409031f5e25caf3900a9 (diff) | |
| parent | c5d7a9230e5e277f262b6806b7f4d6b35de5a3fb (diff) | |
Merge branch 'imx-features-for-arnd' of git://git.pengutronix.de/git/imx/linux-2.6 into imx/devel
Conflicts:
arch/arm/mach-mx5/clock-mx51-mx53.c
arch/arm/mach-mx5/devices-imx53.h
Diffstat (limited to 'mm/backing-dev.c')
| -rw-r--r-- | mm/backing-dev.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index d6edf8d14f9c..a87da524a4a0 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -359,6 +359,17 @@ static unsigned long bdi_longest_inactive(void) return max(5UL * 60 * HZ, interval); } +/* + * Clear pending bit and wakeup anybody waiting for flusher thread creation or + * shutdown + */ +static void bdi_clear_pending(struct backing_dev_info *bdi) +{ + clear_bit(BDI_pending, &bdi->state); + smp_mb__after_clear_bit(); + wake_up_bit(&bdi->state, BDI_pending); +} + static int bdi_forker_thread(void *ptr) { struct bdi_writeback *me = ptr; @@ -390,6 +401,13 @@ static int bdi_forker_thread(void *ptr) } spin_lock_bh(&bdi_lock); + /* + * In the following loop we are going to check whether we have + * some work to do without any synchronization with tasks + * waking us up to do work for them. So we have to set task + * state already here so that we don't miss wakeups coming + * after we verify some condition. + */ set_current_state(TASK_INTERRUPTIBLE); list_for_each_entry(bdi, &bdi_list, bdi_list) { @@ -469,11 +487,13 @@ static int bdi_forker_thread(void *ptr) spin_unlock_bh(&bdi->wb_lock); wake_up_process(task); } + bdi_clear_pending(bdi); break; case KILL_THREAD: __set_current_state(TASK_RUNNING); kthread_stop(task); + bdi_clear_pending(bdi); break; case NO_ACTION: @@ -489,16 +509,8 @@ static int bdi_forker_thread(void *ptr) else schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10)); try_to_freeze(); - /* Back to the main loop */ - continue; + break; } - - /* - * Clear pending bit and wakeup anybody waiting to tear us down. - */ - clear_bit(BDI_pending, &bdi->state); - smp_mb__after_clear_bit(); - wake_up_bit(&bdi->state, BDI_pending); } return 0; |