From: Andi Kleen <ak@suse.de>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: akpm@digeo.com
Subject: Re: [PATCH] blockgroup_lock: hashed spinlocks for ext2 and ext3
Date: 14 Apr 2003 22:06:21 +0200 [thread overview]
Message-ID: <1050350782.7912.400.camel@averell> (raw)
In-Reply-To: <200304131113.h3DBDvj2004773@hera.kernel.org>
On Sun, 2003-04-13 at 12:00, Linux Kernel Mailing List wrote:
[....]
>
> These locks are actually fairly generic. However I presented it as something
> which is specific to ext2 and ext3 so that people wouldn't go using them all
> over the place. They consume a lot of storage.
>
> +
> +struct bgl_lock {
> + spinlock_t lock;
> +} ____cacheline_aligned_in_smp;
> +
> +struct blockgroup_lock {
> + struct bgl_lock locks[NR_BG_LOCKS];
> +};
Why don't you use per_cpu data for this ? It can be indexed as well
with per_cpu() and it would safe a lot of space because the padding
would not be all wasted. If you want more than NR_CPUS locks it could be
done using a simple two level index scheme.
-Andi
next parent reply other threads:[~2003-04-14 19:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200304131113.h3DBDvj2004773@hera.kernel.org>
2003-04-14 20:06 ` Andi Kleen [this message]
2003-04-14 21:38 ` [PATCH] blockgroup_lock: hashed spinlocks for ext2 and ext3 Andrew Morton
2003-04-14 21:46 ` Andi Kleen
2003-04-14 21:58 ` Andrew Morton
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