linux-kernel - Re: [PATCH 25/26] aio: use xchg() instead of completion

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>] [day] [month] [year] [list]

Message-ID: <CAJd=RBCXiBC2ctrESGPekrPO067tifg7=tDOx5xQhJESzXK-2w@mail.gmail.com>
Date:	Wed, 19 Dec 2012 19:59:03 +0800
From:	Hillf Danton <dhillf@...il.com>
To:	Kent Overstreet <koverstreet@...gle.com>
Cc:	Zach Brown <zab@...hat.com>, LKML <linux-kernel@...r.kernel.org>,
	Hillf Danton <dhillf@...il.com>
Subject: Re: [PATCH 25/26] aio: use xchg() instead of completion_lock

>@@ -686,9 +685,10 @@ void aio_complete(struct kiocb *iocb, long res, long res2)
> 	 * ctx->ctx_lock to prevent other code from messing with the tail
> 	 * pointer since we might be called from irq context.
> 	 */

Well the comment is stale.

Hillf
>-	spin_lock_irqsave(&ctx->completion_lock, flags);
>+	local_irq_save(flags);
>+	while ((tail = xchg(&ctx->tail, UINT_MAX)) == UINT_MAX)
>+		cpu_relax();
--
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/