From: Jens Axboe <jens.axboe@oracle.com>
To: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [patch] speed up single bio_vec allocation
Date: Mon, 4 Dec 2006 21:43:51 +0100 [thread overview]
Message-ID: <20061204204351.GO4392@kernel.dk> (raw)
In-Reply-To: <000601c717e3$f098a8a0$2589030a@amr.corp.intel.com>
On Mon, Dec 04 2006, Chen, Kenneth W wrote:
> > [...]
> >
> > Another idea would be to kill SLAB_HWCACHE_ALIGN (it's pretty pointless,
> > I bet), and always alloc sizeof(*bio) + sizeof(*bvl) in one go when a
> > bio is allocated. It doesn't add a lot of overhead even for the case
> > where we do > 1 page bios, and it gets rid of the dual allocation for
> > the 1 page bio.
>
> I will try that too. I'm a bit touchy about sharing a cache line for
> different bio. But given that there are 200,000 I/O per second we are
> currently pushing the kernel, the chances of two cpu working on two
> bio that sits in the same cache line are pretty small.
Yep I really think so. Besides, it's not like we are repeatedly writing
to these objects in the first place.
--
Jens Axboe
next prev parent reply other threads:[~2006-12-04 20:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-04 19:27 [patch] speed up single bio_vec allocation Chen, Kenneth W
2006-12-04 20:06 ` Jens Axboe
2006-12-04 20:36 ` Chen, Kenneth W
2006-12-04 20:43 ` Jens Axboe [this message]
2006-12-06 10:08 ` Jens Axboe
2006-12-06 10:56 ` Jens Axboe
2006-12-06 18:19 ` Chen, Kenneth W
2006-12-07 19:22 ` Nate Diller
2006-12-07 19:36 ` Chen, Kenneth W
2006-12-07 21:46 ` Nate Diller
2006-12-07 21:52 ` Chen, Kenneth W
2006-12-07 22:33 ` Nate Diller
2006-12-08 8:01 ` Jens Axboe
2006-12-08 2:27 ` Andi Kleen
2006-12-08 4:23 ` Chen, Kenneth W
2006-12-08 4:37 ` Andi Kleen
-- strict thread matches above, loose matches on Subject: below --
2006-12-08 22:14 Chen, Kenneth W
2006-12-14 20:23 ` Jens Axboe
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