From: Peter Zijlstra <peterz@infradead.org>
To: David Miller <davem@davemloft.net>
Cc: clameter@sgi.com, akpm@linux-foundation.org,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
mathieu.desnoyers@polymtl.ca, penberg@cs.helsinki.fi
Subject: Re: [patch 0/7] [RFC] SLUB: Improve allocpercpu to reduce per cpu access overhead
Date: Fri, 02 Nov 2007 11:28:46 +0100 [thread overview]
Message-ID: <1193999326.27652.348.camel@twins> (raw)
In-Reply-To: <20071101.155805.65012933.davem@davemloft.net>
On Thu, 2007-11-01 at 15:58 -0700, David Miller wrote:
> Since you're the one who wants to change the semantics and guarentees
> of this interface, perhaps it might help if you did some greps around
> the tree to see how alloc_percpu() is actually used. That's what
> I did when I started running into trouble with your patches.
This fancy new BDI stuff also lives off percpu_counter/alloc_percpu().
That means that for example each NFS mount also consumes a number of
words - not quite sure from the top of my head how many, might be in the
order of 24 bytes or something.
I once before started looking at this, because the current
alloc_percpu() can have some false sharing - not that I have machines
that are overly bothered by that. I like the idea of a strict percpu
region, however do be aware of the users.
next prev parent reply other threads:[~2007-11-02 10:28 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-01 0:02 [patch 0/7] [RFC] SLUB: Improve allocpercpu to reduce per cpu access overhead Christoph Lameter
2007-11-01 0:02 ` Christoph Lameter
2007-11-01 0:02 ` [patch 1/7] allocpercpu: Make it a true per cpu allocator by allocating from a per cpu array Christoph Lameter
2007-11-01 0:02 ` Christoph Lameter
2007-11-01 7:24 ` Eric Dumazet
2007-11-01 12:59 ` Christoph Lameter
2007-11-01 0:02 ` [patch 2/7] allocpercpu: Remove functions that are rarely used Christoph Lameter
2007-11-01 0:02 ` Christoph Lameter
2007-11-01 0:02 ` [patch 3/7] Allocpercpu: Do __percpu_disguise() only if CONFIG_DEBUG_VM is set Christoph Lameter
2007-11-01 0:02 ` Christoph Lameter
2007-11-01 7:25 ` Eric Dumazet
2007-11-01 0:02 ` [patch 4/7] Percpu: Add support for this_cpu_offset() to be able to create this_cpu_ptr() Christoph Lameter
2007-11-01 0:02 ` Christoph Lameter
2007-11-01 0:02 ` [patch 5/7] SLUB: Use allocpercpu to allocate per cpu data instead of running our own per cpu allocator Christoph Lameter
2007-11-01 0:02 ` Christoph Lameter
2007-11-01 0:02 ` [patch 6/7] SLUB: No need to cache kmem_cache data in kmem_cache_cpu anymore Christoph Lameter
2007-11-01 0:02 ` Christoph Lameter
2007-11-01 0:02 ` [patch 7/7] SLUB: Optimize per cpu access on the local cpu using this_cpu_ptr() Christoph Lameter
2007-11-01 0:02 ` Christoph Lameter
2007-11-01 0:24 ` [patch 0/7] [RFC] SLUB: Improve allocpercpu to reduce per cpu access overhead David Miller
2007-11-01 0:26 ` Christoph Lameter
2007-11-01 0:27 ` David Miller
2007-11-01 0:31 ` Christoph Lameter
2007-11-01 0:51 ` David Miller
2007-11-01 0:53 ` Christoph Lameter
2007-11-01 1:00 ` David Miller
2007-11-01 1:01 ` Christoph Lameter
2007-11-01 1:09 ` David Miller
2007-11-01 1:12 ` Christoph Lameter
2007-11-01 1:13 ` David Miller
2007-11-01 1:21 ` Christoph Lameter
2007-11-01 5:27 ` David Miller
2007-11-01 4:16 ` Christoph Lameter
2007-11-01 5:38 ` David Miller
2007-11-01 7:01 ` David Miller
2007-11-01 9:14 ` David Miller
2007-11-01 13:03 ` Christoph Lameter
2007-11-01 21:29 ` David Miller
2007-11-01 22:15 ` Christoph Lameter
2007-11-01 22:38 ` David Miller
2007-11-01 22:48 ` Christoph Lameter
2007-11-01 22:58 ` David Miller
2007-11-02 1:06 ` Christoph Lameter
2007-11-02 2:51 ` David Miller
2007-11-02 10:28 ` Peter Zijlstra [this message]
2007-11-02 14:35 ` Christoph Lameter
2007-11-02 15:20 ` Peter Zijlstra
2007-11-02 15:29 ` Christoph Lameter
2007-11-12 10:52 ` Herbert Xu
2007-11-12 10:52 ` Herbert Xu
2007-11-12 19:14 ` Christoph Lameter
2007-11-12 19:48 ` Eric Dumazet
2007-11-12 19:56 ` Christoph Lameter
2007-11-12 20:18 ` Eric Dumazet
2007-11-12 22:46 ` David Miller
2007-11-12 19:57 ` Luck, Tony
2007-11-12 19:57 ` Luck, Tony
2007-11-12 20:14 ` Eric Dumazet
2007-11-12 22:46 ` David Miller
2007-11-12 21:28 ` David Miller
2007-11-01 23:00 ` Eric Dumazet
2007-11-02 0:58 ` Christoph Lameter
2007-11-02 1:40 ` Christoph Lameter
2007-11-01 7:17 ` Eric Dumazet
2007-11-01 7:57 ` David Miller
2007-11-01 13:01 ` Christoph Lameter
2007-11-01 21:25 ` David Miller
2007-11-01 12:57 ` Christoph Lameter
2007-11-01 21:28 ` David Miller
2007-11-01 22:11 ` Christoph Lameter
2007-11-01 22:14 ` David Miller
2007-11-01 22:16 ` Christoph Lameter
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