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From: Oleg Nesterov <oleg@redhat.com>
To: Christian Brauner <brauner@kernel.org>
Cc: NeilBrown <neilb@suse.de>, Al Viro <viro@zeniv.linux.org.uk>,
	Jens Axboe <axboe@kernel.dk>,
	Chuck Lever <chuck.lever@oracle.com>,
	Jeff Layton <jlayton@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-nfs@vger.kernel.org
Subject: Re: [PATCH/RFC] core/nfsd: allow kernel threads to use task_work.
Date: Tue, 28 Nov 2023 14:52:59 +0100	[thread overview]
Message-ID: <20231128135258.GB22743@redhat.com> (raw)
In-Reply-To: <20231128-arsch-halbieren-b2a95645de53@brauner>

On 11/28, Christian Brauner wrote:
>
> Should be simpler if you invert the logic?
>
> COMPLETELY UNTESTED

Agreed, this looks much better to me. But perhaps we can just add the new
PF_KTHREAD_XXX flag and change fput


	--- a/fs/file_table.c
	+++ b/fs/file_table.c
	@@ -445,7 +445,8 @@ void fput(struct file *file)
		if (atomic_long_dec_and_test(&file->f_count)) {
			struct task_struct *task = current;
	 
	-		if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) {
	+		if (likely(!in_interrupt() &&
	+		    task->flags & (PF_KTHREAD|PF_KTHREAD_XXX) != PF_KTHREAD) {
				init_task_work(&file->f_rcuhead, ____fput);
				if (!task_work_add(task, &file->f_rcuhead, TWA_RESUME))
					return;

?

Then nfsd() can simply set PF_KTHREAD_XXX. This looks even simpler to me.

Oleg.


  reply	other threads:[~2023-11-28 13:54 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-27 22:05 [PATCH/RFC] core/nfsd: allow kernel threads to use task_work NeilBrown
2023-11-27 22:30 ` Al Viro
2023-11-27 22:43   ` NeilBrown
2023-11-27 22:59 ` Chuck Lever
2023-11-28  0:16   ` NeilBrown
2023-11-28  1:37     ` Chuck Lever
2023-11-28  2:57       ` NeilBrown
2023-11-28 15:34         ` Chuck Lever
2023-11-30 17:50           ` Jeff Layton
2023-11-28 13:51     ` Christian Brauner
2023-11-28 14:15       ` Jeff Layton
2023-11-28 15:22         ` Chuck Lever
2023-11-28 23:31         ` NeilBrown
2023-11-28 23:20       ` NeilBrown
2023-11-29 11:43         ` Christian Brauner
2023-12-04  1:30           ` NeilBrown
2023-11-29 14:04         ` Chuck Lever
2023-11-30 17:47           ` Jeff Layton
2023-11-30 18:07             ` Chuck Lever
2023-11-30 18:33               ` Jeff Layton
2023-11-28 11:24 ` Christian Brauner
2023-11-28 13:52   ` Oleg Nesterov [this message]
2023-11-28 15:33     ` Christian Brauner
2023-11-28 16:59       ` Oleg Nesterov
2023-11-28 17:29         ` Oleg Nesterov
2023-11-28 23:40           ` NeilBrown
2023-11-29 11:38           ` Christian Brauner
2023-11-28 14:01 ` Oleg Nesterov
2023-11-28 14:20   ` Oleg Nesterov
2023-11-29  0:14   ` NeilBrown
2023-11-29  7:55     ` Oleg Nesterov

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