From: Jens Axboe <jens.axboe@oracle.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Chinner <dgc@sgi.com>, David Miller <davem@davemloft.net>,
cebbert@redhat.com, willy@linux.intel.com, clameter@sgi.com,
nickpiggin@yahoo.com.au, hch@lst.de, mel@skynet.ie,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
suresh.b.siddha@intel.com
Subject: Re: SLUB performance regression vs SLAB
Date: Fri, 5 Oct 2007 11:28:22 +0200 [thread overview]
Message-ID: <20071005092822.GL5711@kernel.dk> (raw)
In-Reply-To: <84144f020710050219k2460631cjfd556d6eae645887@mail.gmail.com>
On Fri, Oct 05 2007, Pekka Enberg wrote:
> Hi,
>
> On 10/5/07, Jens Axboe <jens.axboe@oracle.com> wrote:
> > I'd like to second Davids emails here, this is a serious problem. Having
> > a reproducible test case lowers the barrier for getting the problem
> > fixed by orders of magnitude. It's the difference between the problem
> > getting fixed in a day or two and it potentially lingering for months,
> > because email ping-pong takes forever and "the test team has moved on to
> > other tests, we'll let you know the results of test foo in 3 weeks time
> > when we have a new slot on the box" just removing any developer
> > motivation to work on the issue.
>
> What I don't understand is that why don't the people who _have_ access
> to the test case fix the problem? Unlike slab, slub is not a pile of
> crap that only Christoph can hack on...
Often the people testing are only doing just that, testing. So they
kindly offer to test any patches and so on, which usually takes forever
because of the above limitations in response time, machine availability,
etc.
Writing a small test module to exercise slub/slab in various ways
(allocating from all cpus freeing from one, as described) should not be
too hard. Perhaps that would be enough to find this performance
discrepancy between slab and slub?
--
Jens Axboe
next prev parent reply other threads:[~2007-10-05 9:26 UTC|newest]
Thread overview: 110+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-19 3:36 [00/17] [RFC] Virtual Compound Page Support Christoph Lameter
2007-09-19 3:36 ` [01/17] Vmalloc: Move vmalloc_to_page to mm/vmalloc Christoph Lameter
2007-09-19 3:36 ` [02/17] Vmalloc: add const Christoph Lameter
2007-09-19 3:36 ` [03/17] is_vmalloc_addr(): Check if an address is within the vmalloc boundaries Christoph Lameter
2007-09-19 6:32 ` David Rientjes
2007-09-19 7:24 ` Anton Altaparmakov
2007-09-19 8:09 ` David Rientjes
2007-09-19 8:44 ` Anton Altaparmakov
2007-09-19 9:19 ` David Rientjes
2007-09-19 13:23 ` Anton Altaparmakov
2007-09-19 17:29 ` Christoph Lameter
2007-09-19 17:52 ` Anton Altaparmakov
2007-09-19 17:29 ` Christoph Lameter
2007-09-19 17:52 ` Anton Altaparmakov
2007-09-19 3:36 ` [04/17] vmalloc: clean up page array indexing Christoph Lameter
2007-09-19 3:36 ` [05/17] vunmap: return page array Christoph Lameter
2007-09-19 8:05 ` KAMEZAWA Hiroyuki
2007-09-19 22:15 ` Christoph Lameter
2007-09-20 0:47 ` KAMEZAWA Hiroyuki
2007-09-19 3:36 ` [06/17] vmalloc_address(): Determine vmalloc address from page struct Christoph Lameter
2007-09-19 3:36 ` [07/17] GFP_VFALLBACK: Allow fallback of compound pages to virtual mappings Christoph Lameter
2007-09-19 3:36 ` [08/17] Pass vmalloc address in page->private Christoph Lameter
2007-09-19 3:36 ` [09/17] VFALLBACK: Debugging aid Christoph Lameter
2007-09-19 3:36 ` [10/17] Use GFP_VFALLBACK for sparsemem Christoph Lameter
2007-09-19 3:36 ` [11/17] GFP_VFALLBACK for zone wait table Christoph Lameter
2007-09-19 3:36 ` [12/17] Virtual Compound page allocation from interrupt context Christoph Lameter
2007-09-19 3:36 ` [13/17] Virtual compound page freeing in " Christoph Lameter
2007-09-18 20:36 ` Nick Piggin
2007-09-20 17:50 ` Christoph Lameter
2007-09-19 3:36 ` [14/17] Allow bit_waitqueue to wait on a bit in a vmalloc area Christoph Lameter
2007-09-19 4:12 ` Gabriel C
2007-09-19 17:40 ` Christoph Lameter
2007-09-19 3:36 ` [15/17] SLUB: Support virtual fallback via SLAB_VFALLBACK Christoph Lameter
2007-09-27 21:42 ` Nick Piggin
2007-09-28 17:33 ` Christoph Lameter
2007-09-28 5:14 ` Nick Piggin
2007-10-01 20:50 ` Christoph Lameter
2007-10-02 8:43 ` Nick Piggin
2007-10-04 16:16 ` SLUB performance regression vs SLAB Matthew Wilcox
2007-10-04 17:38 ` Christoph Lameter
2007-10-04 17:50 ` Arjan van de Ven
2007-10-04 17:58 ` Christoph Lameter
2007-10-04 18:26 ` Peter Zijlstra
2007-10-04 20:48 ` David Miller
2007-10-04 20:58 ` Matthew Wilcox
2007-10-04 21:05 ` David Miller
2007-10-04 21:11 ` Christoph Lameter
2007-10-04 18:32 ` Matthew Wilcox
2007-10-04 17:49 ` Christoph Lameter
2007-10-04 19:28 ` Matthew Wilcox
2007-10-04 19:05 ` Christoph Lameter
2007-10-04 19:46 ` Siddha, Suresh B
2007-10-04 20:55 ` David Miller
2007-10-04 21:02 ` Chuck Ebbert
2007-10-04 21:11 ` David Miller
2007-10-04 21:47 ` Chuck Ebbert
2007-10-04 22:07 ` David Miller
2007-10-04 22:23 ` David Chinner
2007-10-05 6:48 ` Jens Axboe
2007-10-05 9:19 ` Pekka Enberg
2007-10-05 9:28 ` Jens Axboe [this message]
2007-10-05 11:12 ` Andi Kleen
2007-10-05 12:39 ` Jens Axboe
2007-10-05 19:31 ` Christoph Lameter
2007-10-05 19:32 ` Christoph Lameter
2007-10-05 11:56 ` Matthew Wilcox
2007-10-05 12:37 ` Jens Axboe
2007-10-05 19:27 ` Christoph Lameter
2007-10-05 20:32 ` Peter Zijlstra
2007-10-05 21:31 ` David Miller
2007-10-04 21:05 ` Matthew Wilcox
2007-10-05 2:43 ` Christoph Lameter
2007-10-05 2:53 ` Arjan van de Ven
2007-09-28 17:55 ` [15/17] SLUB: Support virtual fallback via SLAB_VFALLBACK Peter Zijlstra
2007-09-28 18:20 ` Christoph Lameter
2007-09-28 18:25 ` Peter Zijlstra
2007-09-28 18:41 ` Christoph Lameter
2007-09-28 20:22 ` Nick Piggin
2007-09-28 21:14 ` Mel Gorman
2007-09-28 20:59 ` Mel Gorman
2007-09-29 8:13 ` Andrew Morton
2007-09-29 8:47 ` Peter Zijlstra
2007-09-29 8:53 ` Peter Zijlstra
2007-09-29 9:01 ` Andrew Morton
2007-09-29 9:14 ` Peter Zijlstra
2007-09-29 9:27 ` Andrew Morton
2007-09-28 20:19 ` Nick Piggin
2007-09-29 19:20 ` Andrew Morton
2007-09-29 19:09 ` Nick Piggin
2007-09-30 20:12 ` Andrew Morton
2007-09-30 4:16 ` Nick Piggin
2007-09-29 9:00 ` Andrew Morton
2007-10-01 20:55 ` Christoph Lameter
2007-10-01 21:30 ` Andrew Morton
2007-10-01 21:38 ` Christoph Lameter
2007-10-01 21:45 ` Andrew Morton
2007-10-01 21:52 ` Christoph Lameter
2007-10-02 9:19 ` Peter Zijlstra
2007-09-29 8:45 ` Peter Zijlstra
2007-10-01 21:01 ` Christoph Lameter
2007-10-02 8:37 ` Nick Piggin
2007-09-28 21:05 ` Mel Gorman
2007-10-01 21:10 ` Christoph Lameter
2007-09-19 3:36 ` [16/17] Allow virtual fallback for buffer_heads Christoph Lameter
2007-09-19 3:36 ` [17/17] Allow virtual fallback for dentries Christoph Lameter
2007-09-19 7:34 ` [00/17] [RFC] Virtual Compound Page Support Anton Altaparmakov
2007-09-19 8:34 ` Eric Dumazet
2007-09-19 17:33 ` Christoph Lameter
2007-09-19 8:24 ` Andi Kleen
2007-09-19 17:36 ` Christoph Lameter
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