From: Andrew Morton <akpm@linux-foundation.org>
To: Shaohua Li <shaohua.li@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>, linux-mm <linux-mm@kvack.org>,
lkml <linux-kernel@vger.kernel.org>,
Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH]mmap: add alignment for some variables
Date: Tue, 29 Mar 2011 18:41:10 -0700 [thread overview]
Message-ID: <20110329184110.0086924e.akpm@linux-foundation.org> (raw)
In-Reply-To: <1301449000.3981.52.camel@sli10-conroe>
On Wed, 30 Mar 2011 09:36:40 +0800 Shaohua Li <shaohua.li@intel.com> wrote:
> > how is it that this improves things?
> Hmm, it actually is:
> struct percpu_counter {
> spinlock_t lock;
> s64 count;
> #ifdef CONFIG_HOTPLUG_CPU
> struct list_head list; /* All percpu_counters are on a list */
> #endif
> s32 __percpu *counters;
> } __attribute__((__aligned__(1 << (INTERNODE_CACHE_SHIFT))))
> so lock and count are in one cache line.
____cacheline_aligned_in_smp would achieve that?
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org>
To: Shaohua Li <shaohua.li@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>, linux-mm <linux-mm@kvack.org>,
lkml <linux-kernel@vger.kernel.org>,
Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH]mmap: add alignment for some variables
Date: Tue, 29 Mar 2011 18:41:10 -0700 [thread overview]
Message-ID: <20110329184110.0086924e.akpm@linux-foundation.org> (raw)
In-Reply-To: <1301449000.3981.52.camel@sli10-conroe>
On Wed, 30 Mar 2011 09:36:40 +0800 Shaohua Li <shaohua.li@intel.com> wrote:
> > how is it that this improves things?
> Hmm, it actually is:
> struct percpu_counter {
> spinlock_t lock;
> s64 count;
> #ifdef CONFIG_HOTPLUG_CPU
> struct list_head list; /* All percpu_counters are on a list */
> #endif
> s32 __percpu *counters;
> } __attribute__((__aligned__(1 << (INTERNODE_CACHE_SHIFT))))
> so lock and count are in one cache line.
____cacheline_aligned_in_smp would achieve that?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-03-30 1:40 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-28 1:58 [PATCH]mmap: add alignment for some variables Shaohua Li
2011-03-28 1:58 ` Shaohua Li
2011-03-28 16:55 ` Andi Kleen
2011-03-28 16:55 ` Andi Kleen
2011-03-29 0:54 ` Shaohua Li
2011-03-29 0:54 ` Shaohua Li
2011-03-29 22:24 ` Andrew Morton
2011-03-29 22:24 ` Andrew Morton
2011-03-29 22:38 ` Christoph Lameter
2011-03-29 22:38 ` Christoph Lameter
2011-03-30 1:01 ` Shaohua Li
2011-03-30 1:01 ` Shaohua Li
2011-03-30 1:06 ` Andrew Morton
2011-03-30 1:06 ` Andrew Morton
2011-03-30 1:17 ` Shaohua Li
2011-03-30 1:17 ` Shaohua Li
2011-03-30 1:25 ` Andrew Morton
2011-03-30 1:25 ` Andrew Morton
2011-03-30 1:36 ` Shaohua Li
2011-03-30 1:36 ` Shaohua Li
2011-03-30 1:41 ` Andrew Morton [this message]
2011-03-30 1:41 ` Andrew Morton
2011-03-30 1:54 ` Shaohua Li
2011-03-30 1:54 ` Shaohua Li
2011-03-30 2:10 ` Andrew Morton
2011-03-30 2:10 ` Andrew Morton
2011-03-30 2:35 ` Shaohua Li
2011-03-30 2:35 ` Shaohua Li
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110329184110.0086924e.akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=riel@redhat.com \
--cc=shaohua.li@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.