From: Alexander Graf <agraf@suse.de>
To: Max Reitz <mreitz@redhat.com>, qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Alberto Garcia <berto@igalia.com>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 1/3] qcow2: Set MIN_L2_CACHE_SIZE to 2
Date: Mon, 01 Jun 2015 18:12:48 +0200 [thread overview]
Message-ID: <556C8480.3060907@suse.de> (raw)
In-Reply-To: <1433174959-7176-2-git-send-email-mreitz@redhat.com>
On 01.06.15 18:09, Max Reitz wrote:
> The L2 cache must cover at least two L2 tables, because during COW two
> L2 tables are accessed simultaneously.
>
> Reported-by: Alexander Graf <agraf@suse.de>
> Cc: qemu-stable <qemu-stable@nongnu.org>
> Signed-off-by: Max Reitz <mreitz@redhat.com>
Tested-by: Alexander Graf <agraf@suse.de>
Alex
> ---
> block/qcow2.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/block/qcow2.h b/block/qcow2.h
> index 0076512..aa20022 100644
> --- a/block/qcow2.h
> +++ b/block/qcow2.h
> @@ -62,7 +62,8 @@
> #define MIN_CLUSTER_BITS 9
> #define MAX_CLUSTER_BITS 21
>
> -#define MIN_L2_CACHE_SIZE 1 /* cluster */
> +/* Must be at least 2 to cover COW */
> +#define MIN_L2_CACHE_SIZE 2 /* clusters */
>
> /* Must be at least 4 to cover all cases of refcount table growth */
> #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
>
next prev parent reply other threads:[~2015-06-01 16:13 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-01 16:09 [Qemu-devel] [PATCH 0/3] qcow2: Fix MIN_L2_CACHE_SIZE Max Reitz
2015-06-01 16:09 ` [Qemu-devel] [PATCH 1/3] qcow2: Set MIN_L2_CACHE_SIZE to 2 Max Reitz
2015-06-01 16:10 ` Max Reitz
2015-06-01 16:12 ` Alexander Graf [this message]
2015-06-01 16:14 ` Alberto Garcia
2015-06-01 16:09 ` [Qemu-devel] [PATCH 2/3] iotests: qcow2 COW with minimal L2 cache size Max Reitz
2015-06-01 17:01 ` Alberto Garcia
2015-06-01 16:09 ` [Qemu-devel] [PATCH 3/3] qcow2: Add DEFAULT_L2_CACHE_CLUSTERS Max Reitz
2015-06-01 17:16 ` Alberto Garcia
2015-06-02 9:31 ` [Qemu-devel] [PATCH 0/3] qcow2: Fix MIN_L2_CACHE_SIZE Kevin Wolf
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=556C8480.3060907@suse.de \
--to=agraf@suse.de \
--cc=berto@igalia.com \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
/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.