From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, Christoph Lameter <cl@linux.com>,
Alexander Duyck <alexander.duyck@gmail.com>,
netdev@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@redhat.com>,
brouer@redhat.com
Subject: Re: [MM PATCH V4.1 5/6] slub: support for bulk free with SLUB freelists
Date: Wed, 7 Oct 2015 12:39:19 +0200 [thread overview]
Message-ID: <20151007123919.27a9c823@redhat.com> (raw)
In-Reply-To: <20151005212639.35932b6c@redhat.com>
On Mon, 5 Oct 2015 21:26:39 +0200 Jesper Dangaard Brouer <brouer@redhat.com> wrote:
> On Fri, 2 Oct 2015 14:50:44 -0700 Andrew Morton <akpm@linux-foundation.org> wrote:
>
[...]
>
> > Deleting the BUG altogether sounds the best solution. As long as the
> > kernel crashes in some manner, we'll be able to work out what happened.
> > And it's cant-happen anyway, isn't it?
>
> To me WARN_ON() seems like a good "documentation" if it does not hurt
> performance. I don't think removing the WARN_ON() will improve
> performance, but I'm willing to actually test if it matters.
I tested removing BUG/WARN_ON altogether, and it gives slightly worse
performance. The icache-misses only increase approx 14% (not 112% as
before). This, I'm willing to attribute to some code alignment issue.
Thus, let us just keep the WARN_ON() and move along.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
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next prev parent reply other threads:[~2015-10-07 10:39 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-28 12:26 [PATCH 0/7] Further optimizing SLAB/SLUB bulking Jesper Dangaard Brouer
2015-09-28 12:26 ` [PATCH 1/7] slub: create new ___slab_alloc function that can be called with irqs disabled Jesper Dangaard Brouer
2015-09-28 12:26 ` [PATCH 2/7] slub: Avoid irqoff/on in bulk allocation Jesper Dangaard Brouer
2015-09-28 12:26 ` [PATCH 3/7] slub: mark the dangling ifdef #else of CONFIG_SLUB_DEBUG Jesper Dangaard Brouer
2015-09-28 13:49 ` Christoph Lameter
2015-09-28 12:26 ` [PATCH 4/7] slab: implement bulking for SLAB allocator Jesper Dangaard Brouer
2015-09-28 15:11 ` Christoph Lameter
2015-09-28 12:26 ` [PATCH 5/7] slub: support for bulk free with SLUB freelists Jesper Dangaard Brouer
2015-09-28 15:16 ` Christoph Lameter
2015-09-28 15:51 ` Jesper Dangaard Brouer
2015-09-28 16:28 ` Christoph Lameter
2015-09-29 7:32 ` Jesper Dangaard Brouer
2015-09-28 16:30 ` Christoph Lameter
2015-09-29 7:12 ` Jesper Dangaard Brouer
2015-09-28 12:26 ` [PATCH 6/7] slub: optimize bulk slowpath free by detached freelist Jesper Dangaard Brouer
2015-09-28 15:22 ` Christoph Lameter
2015-09-28 12:26 ` [PATCH 7/7] slub: do prefetching in kmem_cache_alloc_bulk() Jesper Dangaard Brouer
2015-09-28 14:53 ` Alexander Duyck
2015-09-28 15:59 ` Jesper Dangaard Brouer
2015-09-29 15:46 ` [MM PATCH V4 0/6] Further optimizing SLAB/SLUB bulking Jesper Dangaard Brouer
2015-09-29 15:47 ` [MM PATCH V4 1/6] slub: create new ___slab_alloc function that can be called with irqs disabled Jesper Dangaard Brouer
2015-09-29 15:47 ` [MM PATCH V4 2/6] slub: Avoid irqoff/on in bulk allocation Jesper Dangaard Brouer
2015-09-29 15:47 ` [MM PATCH V4 3/6] slub: mark the dangling ifdef #else of CONFIG_SLUB_DEBUG Jesper Dangaard Brouer
2015-09-29 15:48 ` [MM PATCH V4 4/6] slab: implement bulking for SLAB allocator Jesper Dangaard Brouer
2015-09-29 15:48 ` [MM PATCH V4 5/6] slub: support for bulk free with SLUB freelists Jesper Dangaard Brouer
2015-09-29 16:38 ` Alexander Duyck
2015-09-29 17:00 ` Jesper Dangaard Brouer
2015-09-29 17:20 ` Alexander Duyck
2015-09-29 18:16 ` Jesper Dangaard Brouer
2015-09-30 11:44 ` [MM PATCH V4.1 " Jesper Dangaard Brouer
2015-09-30 16:03 ` Christoph Lameter
2015-10-01 22:10 ` Andrew Morton
2015-10-02 9:41 ` Jesper Dangaard Brouer
2015-10-02 10:10 ` Christoph Lameter
2015-10-02 10:40 ` Jesper Dangaard Brouer
2015-10-02 13:40 ` Jesper Dangaard Brouer
2015-10-02 21:50 ` Andrew Morton
2015-10-05 19:26 ` Jesper Dangaard Brouer
2015-10-05 21:20 ` Andi Kleen
2015-10-05 23:07 ` Jesper Dangaard Brouer
2015-10-07 12:31 ` Jesper Dangaard Brouer
2015-10-07 13:36 ` Arnaldo Carvalho de Melo
2015-10-07 15:44 ` Andi Kleen
2015-10-07 16:06 ` Andi Kleen
2015-10-05 23:53 ` Jesper Dangaard Brouer
2015-10-07 10:39 ` Jesper Dangaard Brouer [this message]
2015-09-29 15:48 ` [MM PATCH V4 6/6] slub: optimize bulk slowpath free by detached freelist Jesper Dangaard Brouer
2015-10-14 5:15 ` Joonsoo Kim
2015-10-21 7:57 ` Jesper Dangaard Brouer
2015-11-05 5:09 ` Joonsoo Kim
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