From: Peter Zijlstra <peterz@infradead.org>
To: Petr Mladek <pmladek@suse.cz>
Cc: linux-nfs@vger.kernel.org, Borislav Petkov <bp@suse.de>,
Thomas Gleixner <tglx@linutronix.de>,
Jiri Kosina <jkosina@suse.cz>,
Richard Weinberger <richard@nod.at>,
Trond Myklebust <trond.myklebust@primarydata.com>,
Oleg Nesterov <oleg@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org, Michal Hocko <mhocko@suse.cz>,
Chris Mason <clm@fb.com>, Ingo Molnar <mingo@redhat.com>,
linux-mtd@lists.infradead.org, linux-api@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Tejun Heo <tj@kernel.org>,
live-patching@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
David Woodhouse <dwmw2@infradead.org>,
Anna Schumaker <anna.schumaker@netapp.com>
Subject: Re: [RFC PATCH 09/18] kthread: Make it easier to correctly sleep in iterant kthreads
Date: Mon, 08 Jun 2015 13:39:55 +0200 [thread overview]
Message-ID: <1433763595.1495.35.camel@twins> (raw)
In-Reply-To: <20150608100107.GA3135@pathway.suse.cz>
On Mon, 2015-06-08 at 12:01 +0200, Petr Mladek wrote:
> Just to be sure. Do you suggest to use TASK_IDLE everywhere in
> kthreads or only when the uninterruptible sleep is really needed?
Always, only use INTERRUPTIBLE when you're actually interruptible, that
is you want signals or such muck to terminate your wait.
> IMHO, we should not use TASK_IDLE in freezable kthreads because
> it would break freezing.
How so? The task is IDLE, its not doing anything.
> Well, we could freezable_schedule() but only
> on locations where it is safe to get freezed. Anyway, we need to
> be careful here.
s/freezed/frozen/
Bah, you made me look at the freezer code, karma reduction for you.
And this is the arch typical freeze point if ever there was one, you're
checking kthread_stop, if we can terminate the kthread, we can certainly
get frozen.
> BTW: What is the preferred way of freezing, please? Is it better
> to end up in the fridge or is it fine to call freezer_do_not_count();
> or set PF_NOFREEZE when it is safe?
freezable_schedule() is fine in this case.
next prev parent reply other threads:[~2015-06-08 11:39 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-05 15:00 [RFC PATCH 00/18] kthreads/signal: Safer kthread API and signal handling Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 01/18] kthread: Allow to call __kthread_create_on_node() with va_list args Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 02/18] kthread: Add API for iterant kthreads Petr Mladek
2015-06-09 6:23 ` Tejun Heo
2015-06-15 12:46 ` Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 03/18] kthread: Add kthread_stop_current() Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 04/18] signal: Rename kernel_sigaction() to kthread_sigaction() and clean it up Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 05/18] freezer/scheduler: Add freezable_cond_resched() Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 06/18] signal/kthread: Initial implementation of kthread signal handling Petr Mladek
2015-06-06 21:58 ` Oleg Nesterov
2015-06-08 13:51 ` Petr Mladek
2015-06-08 21:13 ` Oleg Nesterov
2015-06-15 13:13 ` Petr Mladek
2015-06-15 19:14 ` Oleg Nesterov
2015-06-16 7:54 ` Petr Mladek
2015-06-09 7:10 ` Tejun Heo
2015-06-09 12:15 ` Jiri Kosina
2015-06-10 3:13 ` Tejun Heo
2015-06-05 15:01 ` [RFC PATCH 07/18] kthread: Make iterant kthreads freezable by default Petr Mladek
2015-06-09 7:20 ` Tejun Heo
2015-06-09 15:53 ` Petr Mladek
2015-06-10 4:31 ` Tejun Heo
2015-06-12 13:24 ` Petr Mladek
2015-06-13 23:22 ` Tejun Heo
2015-06-15 9:28 ` Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 08/18] kthread: Allow to get struct kthread_iterant from task_struct Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 09/18] kthread: Make it easier to correctly sleep in iterant kthreads Petr Mladek
2015-06-05 16:10 ` Peter Zijlstra
2015-06-08 10:01 ` Petr Mladek
2015-06-08 11:39 ` Peter Zijlstra [this message]
2015-06-09 15:25 ` Petr Mladek
2015-06-10 9:05 ` Peter Zijlstra
2015-06-09 7:32 ` Tejun Heo
2015-06-08 17:48 ` Steven Rostedt
2015-06-10 9:07 ` Peter Zijlstra
2015-06-10 14:07 ` Steven Rostedt
2015-06-11 4:28 ` Jiri Kosina
2015-06-05 15:01 ` [RFC PATCH 10/18] jffs2: Remove forward definition of jffs2_garbage_collect_thread() Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 11/18] jffs2: Convert jffs2_gcd_mtd kthread into the iterant API Petr Mladek
2015-06-06 21:16 ` Oleg Nesterov
2015-06-06 21:32 ` Jiri Kosina
2015-06-06 22:30 ` Oleg Nesterov
2015-06-06 22:44 ` Jiri Kosina
2015-06-06 22:58 ` Oleg Nesterov
2015-06-05 15:01 ` [RFC PATCH 12/18] lockd: Convert the central lockd service to kthread_iterant API Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 13/18] ring_buffer: Use iterant kthreads API in the ring buffer benchmark Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 14/18] ring_buffer: Allow to cleanly freeze the ring buffer benchmark kthreads Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 15/18] ring_buffer: Allow to exit the ring buffer benchmark immediately Petr Mladek
2015-06-08 17:44 ` Steven Rostedt
2015-06-15 15:23 ` Petr Mladek
2015-06-15 15:33 ` Steven Rostedt
2015-06-15 15:54 ` Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 16/18] kthread: Support interruptible sleep with a timeout by iterant kthreads Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 17/18] ring_buffer: Use the new API for a sleep with a timeout in the benchmark Petr Mladek
2015-06-05 15:01 ` [RFC PATCH 18/18] jffs2: Use the new API for a sleep with a timeout Petr Mladek
2015-06-05 16:22 ` [RFC PATCH 00/18] kthreads/signal: Safer kthread API and signal handling Peter Zijlstra
2015-06-09 6:14 ` Tejun Heo
2015-06-10 10:40 ` Peter Zijlstra
2015-06-11 22:02 ` Tejun Heo
2015-06-09 6:10 ` Tejun Heo
2015-06-09 7:58 ` Tejun Heo
2015-06-17 11:34 ` Christoph Hellwig
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