qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Kevin Wolf <kwolf@redhat.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, qemu-devel@nongnu.org
Subject: [Qemu-devel] [PULL 03/25] qcow2: Set MIN_L2_CACHE_SIZE to 2
Date: Fri, 12 Jun 2015 18:23:12 +0200	[thread overview]
Message-ID: <1434126214-11681-4-git-send-email-kwolf@redhat.com> (raw)
In-Reply-To: <1434126214-11681-1-git-send-email-kwolf@redhat.com>

From: Max Reitz <mreitz@redhat.com>

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>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 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 */
-- 
1.8.3.1

  parent reply	other threads:[~2015-06-12 16:23 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-12 16:23 [Qemu-devel] [PULL 00/25] Block layer core and image format patches Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 01/25] iotests: remove assertIsNotNone call Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 02/25] qemu-iotests: Fix 128 if sudo required Kevin Wolf
2015-06-12 16:23 ` Kevin Wolf [this message]
2015-06-12 16:23 ` [Qemu-devel] [PULL 04/25] iotests: qcow2 COW with minimal L2 cache size Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 05/25] qcow2: Add DEFAULT_L2_CACHE_CLUSTERS Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 06/25] vmdk: Fix index_in_cluster calculation in vmdk_co_get_block_status Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 07/25] vmdk: Use vmdk_find_index_in_cluster everywhere Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 08/25] raw-posix: Fix .bdrv_co_get_block_status() for unaligned image size Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 09/25] block: record new size in bdrv_dirty_bitmap_truncate Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 10/25] block: Change bitmap truncate conditional to assertion Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 11/25] block: driver should override flags in bdrv_open() Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 12/25] iotests: Add tests for overriding BDRV_O_PROTOCOL Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 13/25] qdict: Add qdict_array_entries() Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 14/25] qdict: Add qdict_{set,copy}_default() Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 15/25] check-qdict: Test cases for new functions Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 16/25] quorum: Use bdrv_open_image() Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 17/25] vmdk: " Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 18/25] block: Use macro for cache option names Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 19/25] block: Use QemuOpts in bdrv_open_common() Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 20/25] block: Move flag inheritance to bdrv_open_inherit() Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 21/25] block: Drain requests before swapping nodes in bdrv_swap() Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 22/25] queue.h: Add QLIST_FIX_HEAD_PTR() Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 23/25] block: Add list of children to BlockDriverState Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 24/25] block: Add BlockDriverState.inherits_from Kevin Wolf
2015-06-12 16:23 ` [Qemu-devel] [PULL 25/25] block: Fix reopen flag inheritance Kevin Wolf
2015-06-15 12:24 ` [Qemu-devel] [PULL 00/25] Block layer core and image format patches Peter Maydell

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=1434126214-11681-4-git-send-email-kwolf@redhat.com \
    --to=kwolf@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).