From: Max Reitz <mreitz@redhat.com>
To: Alberto Garcia <berto@igalia.com>, qemu-devel@nongnu.org
Cc: Stefan Hajnoczi <stefanha@redhat.com>, qemu-block@nongnu.org
Subject: Re: [Qemu-devel] [Qemu-block] [PATCH 1/7] qcow2: use one single memory block for the L2/refcount cache tables
Date: Fri, 08 May 2015 17:03:12 +0200 [thread overview]
Message-ID: <554CD030.6060908@redhat.com> (raw)
In-Reply-To: <9947b50525d2d06d9a9c0bacb11cab8a9710ede1.1430919406.git.berto@igalia.com>
On 06.05.2015 15:39, Alberto Garcia wrote:
> The qcow2 L2/refcount cache contains one separate table for each cache
> entry. Doing one allocation per table adds unnecessary overhead and it
> also requires us to store the address of each table separately.
>
> Since the size of the cache is constant during its lifetime, it's
> better to have an array that contains all the tables using one single
> allocation.
>
> In my tests measuring freshly created caches with sizes 128MB (L2) and
> 32MB (refcount) this uses around 10MB of RAM less.
>
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
> block/qcow2-cache.c | 55 ++++++++++++++++++++++++--------------------------
> block/qcow2-cluster.c | 12 +++++------
> block/qcow2-refcount.c | 8 +++++---
> block/qcow2.h | 3 ++-
> 4 files changed, 39 insertions(+), 39 deletions(-)
Reviewed-by: Max Reitz <mreitz@redhat.com>
next prev parent reply other threads:[~2015-05-08 15:04 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-06 13:39 [Qemu-devel] [PATCH v2 0/7] qcow2 L2/refcount cache improvements Alberto Garcia
2015-05-06 13:39 ` [Qemu-devel] [PATCH 1/7] qcow2: use one single memory block for the L2/refcount cache tables Alberto Garcia
2015-05-07 10:14 ` Stefan Hajnoczi
2015-05-08 15:03 ` Max Reitz [this message]
2015-05-06 13:39 ` [Qemu-devel] [PATCH 2/7] qcow2: simplify qcow2_cache_put() and qcow2_cache_entry_mark_dirty() Alberto Garcia
2015-05-07 10:15 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2015-05-08 15:12 ` Max Reitz
2015-05-06 13:39 ` [Qemu-devel] [PATCH 3/7] qcow2: use an LRU algorithm to replace entries from the L2 cache Alberto Garcia
2015-05-07 10:16 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2015-05-07 14:55 ` [Qemu-devel] " Eric Blake
2015-05-07 15:01 ` Alberto Garcia
2015-05-08 15:22 ` [Qemu-devel] [Qemu-block] " Max Reitz
2015-05-06 13:39 ` [Qemu-devel] [PATCH 4/7] qcow2: remove qcow2_cache_find_entry_to_replace() Alberto Garcia
2015-05-07 10:17 ` Stefan Hajnoczi
2015-05-08 15:27 ` [Qemu-devel] [Qemu-block] " Max Reitz
2015-05-06 13:39 ` [Qemu-devel] [PATCH 5/7] qcow2: use a hash to look for entries in the L2 cache Alberto Garcia
2015-05-07 10:18 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2015-05-08 15:46 ` Max Reitz
2015-05-08 16:48 ` Alberto Garcia
2015-05-06 13:39 ` [Qemu-devel] [PATCH 6/7] qcow2: make qcow2_cache_put() a void function Alberto Garcia
2015-05-07 10:20 ` Stefan Hajnoczi
2015-05-08 15:51 ` [Qemu-devel] [Qemu-block] " Max Reitz
2015-05-08 16:59 ` Alberto Garcia
2015-05-06 13:39 ` [Qemu-devel] [PATCH 7/7] qcow2: style fixes in qcow2-cache.c Alberto Garcia
2015-05-07 10:20 ` Stefan Hajnoczi
2015-05-08 15:52 ` [Qemu-devel] [Qemu-block] " Max Reitz
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