From: Andrew Morton <akpm@osdl.org>
To: kiran@scalex86.org, linux-kernel@vger.kernel.org, shai@scalex86.org
Subject: Re: [patch] Cache align futex hash buckets
Date: Mon, 20 Feb 2006 15:34:19 -0800 [thread overview]
Message-ID: <20060220153419.5ea8dd89.akpm@osdl.org> (raw)
In-Reply-To: <20060220153320.793b6a7d.akpm@osdl.org>
Andrew Morton <akpm@osdl.org> wrote:
>
> Ravikiran G Thirumalai <kiran@scalex86.org> wrote:
> >
> > Following change places each element of the futex_queues hashtable on a
> > different cacheline. Spinlocks of adjacent hash buckets lie on the same
> > cacheline otherwise.
> >
> > Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
> > Signed-off-by: Shai Fultheim <shai@scalex86.org>
> >
> > Index: linux-2.6.16-rc2/kernel/futex.c
> > ===================================================================
> > --- linux-2.6.16-rc2.orig/kernel/futex.c 2006-02-07 23:14:04.000000000 -0800
> > +++ linux-2.6.16-rc2/kernel/futex.c 2006-02-09 14:04:22.000000000 -0800
> > @@ -100,9 +100,10 @@ struct futex_q {
> > struct futex_hash_bucket {
> > spinlock_t lock;
> > struct list_head chain;
> > -};
> > +} ____cacheline_internodealigned_in_smp;
> >
> > -static struct futex_hash_bucket futex_queues[1<<FUTEX_HASHBITS];
> > +static struct futex_hash_bucket futex_queues[1<<FUTEX_HASHBITS]
> > + __cacheline_aligned_in_smp;
> >
>
> How much memory does that thing end up consuming?
I think a megabyte?
next prev parent reply other threads:[~2006-02-20 23:35 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-02-20 23:32 [patch] Cache align futex hash buckets Ravikiran G Thirumalai
2006-02-20 23:33 ` Andrew Morton
2006-02-20 23:34 ` Andrew Morton [this message]
2006-02-21 0:09 ` Ravikiran G Thirumalai
2006-02-21 0:23 ` Andrew Morton
2006-02-21 1:04 ` Ravikiran G Thirumalai
2006-02-21 1:09 ` Andrew Morton
2006-02-21 1:39 ` Ravikiran G Thirumalai
2006-02-21 14:44 ` Andi Kleen
2006-02-21 3:30 ` Nick Piggin
2006-02-21 18:33 ` Christoph Lameter
2006-02-21 23:14 ` Christoph Lameter
2006-02-22 0:40 ` Nick Piggin
2006-02-22 2:08 ` Andrew Morton
2006-02-22 2:35 ` Ravikiran G Thirumalai
2006-02-22 2:37 ` Nick Piggin
2006-02-22 20:17 ` Ravikiran G Thirumalai
2006-02-22 20:50 ` Andrew Morton
[not found] ` <20060223015144.GC3663@localhost.localdomain>
2006-02-23 2:08 ` Ravikiran G Thirumalai
2006-02-21 20:20 ` Ravikiran G Thirumalai
2006-02-22 0:45 ` Nick Piggin
2006-02-22 2:09 ` Andrew Morton
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