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| author | Tejun Heo <tj@kernel.org> | 2010-06-29 10:07:12 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-06-29 10:07:12 +0200 |
| commit | a0a1a5fd4fb15ec61117c759fe9f5c16c53d9e9c (patch) | |
| tree | 6df8eddcaeff6cde892c8cae6bdfa7653805e144 /kernel/power | |
| parent | workqueue: implement per-cwq active work limit (diff) | |
| download | linux-a0a1a5fd4fb15ec61117c759fe9f5c16c53d9e9c.tar.xz linux-a0a1a5fd4fb15ec61117c759fe9f5c16c53d9e9c.zip | |
workqueue: reimplement workqueue freeze using max_active
Currently, workqueue freezing is implemented by marking the worker
freezeable and calling try_to_freeze() from dispatch loop.
Reimplement it using cwq->limit so that the workqueue is frozen
instead of the worker.
* workqueue_struct->saved_max_active is added which stores the
specified max_active on initialization.
* On freeze, all cwq->max_active's are quenched to zero. Freezing is
complete when nr_active on all cwqs reach zero.
* On thaw, all cwq->max_active's are restored to wq->saved_max_active
and the worklist is repopulated.
This new implementation allows having single shared pool of workers
per cpu.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/power')
| -rw-r--r-- | kernel/power/process.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/kernel/power/process.c b/kernel/power/process.c index 71ae29052ab6..028a99598f49 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -15,6 +15,7 @@ #include <linux/syscalls.h> #include <linux/freezer.h> #include <linux/delay.h> +#include <linux/workqueue.h> /* * Timeout for stopping processes @@ -35,6 +36,7 @@ static int try_to_freeze_tasks(bool sig_only) struct task_struct *g, *p; unsigned long end_time; unsigned int todo; + bool wq_busy = false; struct timeval start, end; u64 elapsed_csecs64; unsigned int elapsed_csecs; @@ -42,6 +44,10 @@ static int try_to_freeze_tasks(bool sig_only) do_gettimeofday(&start); end_time = jiffies + TIMEOUT; + + if (!sig_only) + freeze_workqueues_begin(); + while (true) { todo = 0; read_lock(&tasklist_lock); @@ -63,6 +69,12 @@ static int try_to_freeze_tasks(bool sig_only) todo++; } while_each_thread(g, p); read_unlock(&tasklist_lock); + + if (!sig_only) { + wq_busy = freeze_workqueues_busy(); + todo += wq_busy; + } + if (!todo || time_after(jiffies, end_time)) break; @@ -86,8 +98,12 @@ static int try_to_freeze_tasks(bool sig_only) */ printk("\n"); printk(KERN_ERR "Freezing of tasks failed after %d.%02d seconds " - "(%d tasks refusing to freeze):\n", - elapsed_csecs / 100, elapsed_csecs % 100, todo); + "(%d tasks refusing to freeze, wq_busy=%d):\n", + elapsed_csecs / 100, elapsed_csecs % 100, + todo - wq_busy, wq_busy); + + thaw_workqueues(); + read_lock(&tasklist_lock); do_each_thread(g, p) { task_lock(p); @@ -157,6 +173,7 @@ void thaw_processes(void) oom_killer_enable(); printk("Restarting tasks ... "); + thaw_workqueues(); thaw_tasks(true); thaw_tasks(false); schedule(); |