From: Eric Biggers <ebiggers3@gmail.com>
To: linux-fsdevel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Christoph Lameter <cl@linux.com>,
linux-kernel@vger.kernel.org, Eric Biggers <ebiggers@google.com>
Subject: Re: [PATCH] fs/buffer.c: make bh_lru_install() more efficient
Date: Sat, 25 Mar 2017 20:34:30 -0700 [thread overview]
Message-ID: <20170326033430.GA20915@zzz> (raw)
In-Reply-To: <20161229193445.1913-1-ebiggers3@gmail.com>
On Thu, Dec 29, 2016 at 01:34:45PM -0600, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> To install a buffer_head into the cpu's LRU queue, bh_lru_install()
> would construct a new copy of the queue and then memcpy it over the real
> queue. But it's easily possible to do the update in-place, which is
> faster and simpler. Some work can also be skipped if the buffer_head
> was already in the queue.
>
> As a microbenchmark I timed how long it takes to run sb_getblk()
> 10,000,000 times alternating between BH_LRU_SIZE + 1 blocks.
> Effectively, this benchmarks looking up buffer_heads that are in the
> page cache but not in the LRU:
>
> Before this patch: 1.758s
> After this patch: 1.653s
>
> This patch also removes about 350 bytes of compiled code (on x86_64),
> partly due to removal of the memcpy() which was being inlined+unrolled.
>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
Ping? Al, do you have any interest in taking this patch?
- Eric
next prev parent reply other threads:[~2017-03-26 3:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-29 19:34 [PATCH] fs/buffer.c: make bh_lru_install() more efficient Eric Biggers
2017-03-26 3:34 ` Eric Biggers [this message]
2017-06-03 13:56 ` Sean Fu
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