From: Tejun Heo <tj@kernel.org>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>,
Herbert Xu <herbert@gondor.apana.org.au>,
akpm@linux-foundation.org, hpa@zytor.com, brgerst@gmail.com,
ebiederm@xmission.com, cl@linux-foundation.org, travis@sgi.com,
linux-kernel@vger.kernel.org, steiner@sgi.com, hugh@veritas.com,
"David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Subject: Re: [PATCH] percpu: add optimized generic percpu accessors
Date: Tue, 20 Jan 2009 15:25:50 +0900 [thread overview]
Message-ID: <49756E6E.2060409@kernel.org> (raw)
In-Reply-To: <200901201328.24605.rusty@rustcorp.com.au>
Rusty Russell wrote:
> The generic versions Tejun posted are not softirq safe, so not
> suitable for network counters. To figure out what semantics we
> really want we need to we must audit the users; I'm sorry I haven't
> finished that task (and won't until after the conference).
No, they're not. They're preempt safe as mentioned in the comment and
is basically just generalization of the original x86 versions used by
x86_64 on SMP before pda and percpu areas were merged. I agree that
it's something very close to local_t and it would be nice to see those
somehow unified (and I have patches which make use of local_t in my
queue waiting for dynamic percpu allocation).
Another question to ask is whether to keep using separate interfaces
for static and dynamic percpu variables or migrate to something which
can take both.
Thanks.
--
tejun
next prev parent reply other threads:[~2009-01-20 6:26 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-13 10:38 [PATCHSET linux-2.6-x86:tip] x86: make percpu offsets zero-based on SMP Tejun Heo
2009-01-13 10:38 ` [PATCH 01/13] x86_64: fix pda_to_op() Tejun Heo
2009-01-13 10:38 ` [PATCH 02/13] x86: make early_per_cpu() a lvalue and use it Tejun Heo
2009-01-13 11:43 ` [PATCH 02/13 UPDATED] " Tejun Heo
2009-01-13 10:38 ` [PATCH 03/13] x86_64: Cleanup early setup_percpu references Tejun Heo
2009-01-13 10:38 ` [PATCH 04/13] x86_32: make vmlinux_32.lds.S use PERCPU() macro Tejun Heo
2009-01-13 10:38 ` [PATCH 05/13] x86_64: make percpu symbols zerobased on SMP Tejun Heo
2009-01-13 10:38 ` [PATCH 06/13] x86_64: load pointer to pda into %gs while brining up a CPU Tejun Heo
2009-01-13 10:38 ` [PATCH 07/13] x86_64: use static _cpu_pda array Tejun Heo
2009-01-13 10:38 ` [PATCH 08/13] x86_64: fold pda into percpu area on SMP Tejun Heo
2009-01-13 10:38 ` [PATCH 09/13] x86_64: merge 64 and 32 SMP percpu handling Tejun Heo
2009-01-13 10:38 ` [PATCH 10/13] x86_64: make pda a percpu variable Tejun Heo
2009-01-13 10:38 ` [PATCH 11/13] x86_64: convert pda ops to wrappers around x86 percpu accessors Tejun Heo
2009-01-13 10:38 ` [PATCH 12/13] x86_64: misc clean up after the percpu update Tejun Heo
2009-01-13 10:38 ` [PATCH 13/13] x86_32: make percpu symbols zerobased on SMP Tejun Heo
2009-01-14 0:18 ` Rusty Russell
2009-01-14 2:03 ` Tejun Heo
2009-01-13 10:48 ` [PATCHSET linux-2.6-x86:tip] x86: make percpu offsets zero-based " Tejun Heo
2009-01-13 13:27 ` Brian Gerst
2009-01-13 14:05 ` Tejun Heo
2009-01-13 14:26 ` Brian Gerst
2009-01-13 14:37 ` Tejun Heo
2009-01-14 6:57 ` H. Peter Anvin
2009-01-14 9:38 ` [patch] add optimized generic percpu accessors Ingo Molnar
2009-01-14 9:45 ` Ingo Molnar
[not found] ` <200901151253.44016.rusty@rustcorp.com.au>
2009-01-15 9:55 ` Ingo Molnar
2009-01-15 10:27 ` Tejun Heo
2009-01-15 10:04 ` roel kluin
2009-01-15 10:26 ` Tejun Heo
2009-01-15 11:32 ` Ingo Molnar
2009-01-15 11:36 ` Tejun Heo
2009-01-15 12:22 ` Ingo Molnar
2009-01-15 13:09 ` Tejun Heo
2009-01-15 13:32 ` Ingo Molnar
2009-01-15 13:33 ` Ingo Molnar
2009-01-15 13:39 ` Ingo Molnar
2009-01-15 21:54 ` Tejun Heo
2009-01-16 1:28 ` [PATCH x86/percpu] x86: fix build bug introduced during merge Tejun Heo
2009-01-16 3:25 ` [PATCH x86/percpu] x86_64: initialize this_cpu_off to __per_cpu_load Tejun Heo
2009-01-16 13:16 ` Ingo Molnar
2009-01-16 13:47 ` Tejun Heo
[not found] ` <20090116221651.GA32736@elte.hu>
[not found] ` <20090116223828.GA9294@elte.hu>
[not found] ` <49716F0E.7060605@gmail.com>
[not found] ` <49716FBF.7080203@kernel.org>
2009-01-17 6:29 ` [PATCH core/percpu REPOST] linker script: add missing VMLINUX_SYMBOL Tejun Heo
2009-01-17 6:32 ` [PATCH] linker script: add missing .data.percpu.page_aligned Tejun Heo
2009-01-17 8:21 ` Ingo Molnar
2009-01-21 23:46 ` Christoph Lameter
2009-01-21 23:45 ` [PATCH core/percpu REPOST] linker script: add missing VMLINUX_SYMBOL Christoph Lameter
2009-01-15 22:34 ` [patch] add optimized generic percpu accessors Ingo Molnar
2009-01-15 20:31 ` Christoph Lameter
2009-01-16 9:41 ` Tejun Heo
2009-01-16 13:23 ` Ingo Molnar
2009-01-16 13:49 ` Tejun Heo
2009-01-15 10:26 ` Tejun Heo
2009-01-15 11:30 ` Ingo Molnar
2009-01-15 11:38 ` Tejun Heo
2009-01-15 12:26 ` Ingo Molnar
2009-01-15 13:04 ` Tejun Heo
2009-01-15 13:07 ` Ingo Molnar
2009-01-15 13:23 ` [PATCH] percpu: " Tejun Heo
2009-01-15 13:36 ` Ingo Molnar
2009-01-15 17:30 ` Andrew Morton
2009-01-15 18:02 ` Ingo Molnar
2009-01-15 18:34 ` Andrew Morton
2009-01-15 18:39 ` Ingo Molnar
2009-01-15 21:53 ` Tejun Heo
2009-01-16 0:12 ` Herbert Xu
2009-01-16 0:15 ` Ingo Molnar
2009-01-16 0:18 ` Herbert Xu
[not found] ` <200901170827.33729.rusty@rustcorp.com.au>
2009-01-16 22:08 ` Ingo Molnar
[not found] ` <200901201328.24605.rusty@rustcorp.com.au>
2009-01-20 6:25 ` Tejun Heo [this message]
2009-01-20 10:36 ` Ingo Molnar
[not found] ` <200901271213.18605.rusty@rustcorp.com.au>
2009-01-27 2:24 ` Tejun Heo
2009-01-27 13:13 ` Ingo Molnar
2009-01-27 23:07 ` Tejun Heo
2009-01-28 3:36 ` Tejun Heo
2009-01-28 8:12 ` Tejun Heo
2009-01-27 20:08 ` Christoph Lameter
2009-01-27 21:47 ` David Miller
2009-01-27 22:47 ` Rick Jones
2009-01-28 0:17 ` Luck, Tony
2009-01-28 16:48 ` Christoph Lameter
2009-01-28 17:15 ` Luck, Tony
2009-01-28 16:45 ` Christoph Lameter
2009-01-28 20:47 ` David Miller
2009-01-28 10:38 ` Rusty Russell
2009-01-28 10:56 ` Tejun Heo
2009-01-29 2:06 ` Rusty Russell
2009-01-31 6:11 ` Tejun Heo
2009-01-28 16:50 ` Christoph Lameter
2009-01-28 18:07 ` Mathieu Desnoyers
2009-01-29 18:33 ` Christoph Lameter
2009-01-29 18:48 ` H. Peter Anvin
2009-01-20 10:40 ` Ingo Molnar
2009-01-21 5:52 ` Tejun Heo
2009-01-21 10:05 ` Ingo Molnar
2009-01-21 11:21 ` Eric W. Biederman
2009-01-21 12:45 ` Stephen Hemminger
2009-01-21 14:13 ` Eric W. Biederman
2009-01-21 20:34 ` David Miller
2009-01-16 1:09 ` H. Peter Anvin
[not found] ` <200901170804.18622.rusty@rustcorp.com.au>
2009-01-16 21:59 ` Ingo Molnar
2009-01-16 22:09 ` Ingo Molnar
2009-01-16 14:10 ` Mark Lord
2009-01-15 18:46 ` Ingo Molnar
2009-01-31 10:36 ` Jeremy Fitzhardinge
2009-01-15 13:59 ` [patch] " roel kluin
2009-01-15 21:51 ` Tejun Heo
[not found] ` <200901170748.53734.rusty@rustcorp.com.au>
2009-01-16 21:24 ` Ingo Molnar
2009-01-31 10:30 ` Jeremy Fitzhardinge
2009-01-31 16:00 ` Ingo Molnar
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