linux-kernel - Re: [PATCH] RT: Add priority-queuing and priority-inheritance to workqueue infrastructure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20070801203212.GC225@tv-sign.ru>
Date:	Thu, 2 Aug 2007 00:32:12 +0400
From:	Oleg Nesterov <oleg@...sign.ru>
To:	Daniel Walker <dwalker@...sta.com>
Cc:	Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...e.hu>,
	Gregory Haskins <ghaskins@...ell.com>,
	linux-rt-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] RT: Add priority-queuing and priority-inheritance to workqueue infrastructure

On 08/02, Oleg Nesterov wrote:
>
> And I don't understand why rt_mutex_setprio() is called just before
> calling work->func(). This means that a high-priority work could
> be delayed by the low-priority ->current_work.

Aha, I missed the rt_mutex_setprio() in insert_work().

This is not good either. Suppose we have

	void work_handler(struct work_struct *self)
	{
		if (!try_lock()) {
			// try again later...
			queue_work(wq, self);
			return;
		}

		do_the_work();
	}

What if that work was queued by the low-priority thread, and
then a high-priority thread inserts a new work when work_handler()
is running?

Oleg.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/