[PATCH 01/12] workqueue: add WORKER_RESCUER
rescuer thread must be a worker which is WORKER_NOT_RUNNING:
If it is *not* WORKER_NOT_RUNNING, it will increase the nr_running
and it disables the normal workers wrongly.
So rescuer thread must be WORKER_NOT_RUNNING.
Currently code implement it by always setting WORKER_PREP on rescuer thread,
but this kind of implement is ugly:
A) It reuses WORKER_PREP which is used for a different meaning.
B) It does not told us rescuer thread is WORKER_NOT_RUNNING.
So we add WORKER_RESCUER to fix these two sematic.
Signed-off-by: Lai Jiangshan
---
kernel/workqueue.c |4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 737ab01..ec882a6 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -73,11 +73,12 @@ enum {
WORKER_DIE = 1 << 1, /* die die die */
WORKER_IDLE = 1 << 2, /* is idle */
WORKER_PREP = 1 << 3, /* preparing to run works */
+ WORKER_RESCUER = 1 << 4, /* rescuer thread */
WORKER_CPU_INTENSIVE= 1 << 6, /* cpu intensive */
WORKER_UNBOUND = 1 << 7, /* worker is unbound */
WORKER_NOT_RUNNING = WORKER_PREP | WORKER_UNBOUND |
- WORKER_CPU_INTENSIVE,
+ WORKER_RESCUER | WORKER_CPU_INTENSIVE,
NR_WORKER_POOLS = 2,/* # worker pools per gcwq */
@@ -2405,6 +2406,7 @@ static int rescuer_thread(void *__wq)
bool is_unbound = wq->flags & WQ_UNBOUND;
unsigned int cpu;
+ rescuer->flags |= WORKER_RESCUER;
set_user_nice(current, RESCUER_NICE_LEVEL);
repeat:
set_current_state(TASK_INTERRUPTIBLE);
--
1.7.7.6
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Re: [PATCH 01/12] workqueue: add WORKER_RESCUER
On Thu, Sep 27, 2012 at 01:20:32AM +0800, Lai Jiangshan wrote: > rescuer thread must be a worker which is WORKER_NOT_RUNNING: > If it is *not* WORKER_NOT_RUNNING, it will increase the nr_running > and it disables the normal workers wrongly. > > So rescuer thread must be WORKER_NOT_RUNNING. > > Currently code implement it by always setting WORKER_PREP on rescuer thread, > but this kind of implement is ugly: > A)It reuses WORKER_PREP which is used for a different meaning. > B)It does not told us rescuer thread is WORKER_NOT_RUNNING. > > So we add WORKER_RESCUER to fix these two sematic. Ah, right, we always have WORKER_PREP set for rescuers. So, this doesn't actually change the behavior at all? I'm not necessarily against it but the commit message seems a bit misleading. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 01/12] workqueue: add WORKER_RESCUER
On 09/27/2012 02:07 AM, Tejun Heo wrote: > On Thu, Sep 27, 2012 at 01:20:32AM +0800, Lai Jiangshan wrote: >> rescuer thread must be a worker which is WORKER_NOT_RUNNING: >> If it is *not* WORKER_NOT_RUNNING, it will increase the nr_running >> and it disables the normal workers wrongly. >> >> So rescuer thread must be WORKER_NOT_RUNNING. >> >> Currently code implement it by always setting WORKER_PREP on rescuer thread, >> but this kind of implement is ugly: >> A) It reuses WORKER_PREP which is used for a different meaning. >> B) It does not told us rescuer thread is WORKER_NOT_RUNNING. >> >> So we add WORKER_RESCUER to fix these two sematic. > > Ah, right, we always have WORKER_PREP set for rescuers. So, this > doesn't actually change the behavior at all? No, this doesn't change the behavior at all. > I'm not necessarily > against it but the commit message seems a bit misleading. > I just try my best to say" we need to add WORKER_RESCUER to told us rescuer is WORKER_NOT_RUNNING explicity, using WORKER_PREP only will hide this info" Thanks, Lai -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
