linux-kernel - Re: [PATCH] block: strip out locking optimization in put_io

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: <20120208165611.GC19392@google.com>
Date:	Wed, 8 Feb 2012 08:56:11 -0800
From:	Tejun Heo <tj@...nel.org>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Shaohua Li <shaohua.li@...el.com>, Jens Axboe <axboe@...nel.dk>,
	Vivek Goyal <vgoyal@...hat.com>,
	lkml <linux-kernel@...r.kernel.org>,
	Knut Petersen <Knut_Petersen@...nline.de>, mroos@...ux.ee
Subject: Re: [PATCH] block: strip out locking optimization in
 put_io_context()

On Wed, Feb 08, 2012 at 08:49:20AM -0800, Tejun Heo wrote:
> I'm still a bit lost on where the regression is coming from and
> *suspecting* that queue_lock contention is making the reverse locking
> behave much worse than expected, so I mostly wanted to take that out
> and see what happens.

IOW, we can achieve about the same thing by adding another lock in
request_queue.  The goal is using an inner lock for ioc clearing so
that queue_lock doesn't have to be grabbed inside ioc lock.

Thanks.

-- 
tejun
--
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/