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From: Kevin Wolf <kwolf@redhat.com>
To: Fam Zheng <famz@redhat.com>
Cc: Jeff Cody <jcody@redhat.com>,
	qemu-block@nongnu.org, qemu-devel@nongnu.org,
	Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 1/3] block: Don't wait serialising for non-COR read requests
Date: Tue, 1 Dec 2015 10:54:36 +0100	[thread overview]
Message-ID: <20151201095436.GC6527@noname.str.redhat.com> (raw)
In-Reply-To: <1448962590-2842-2-git-send-email-famz@redhat.com>

Am 01.12.2015 um 10:36 hat Fam Zheng geschrieben:
> The assertion problem was noticed in 06c3916b35a, but it wasn't
> completely fixed, because even though the req is not marked as
> serialising, it still gets serialised by wait_serialising_requests
> against other serialising requests, which could lead to the same
> assertion failure.
> 
> Fix it by even more explicitly skipping the serialising for this
> specific case.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>

And this, my friends, is another example why read/write notifiers are
wrong and should die sooner rather than later. </broken-record>

Kevin

  reply	other threads:[~2015-12-01  9:54 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-01  9:36 [Qemu-devel] [PATCH 0/3] block: Fix assertion failure with before write notifier again Fam Zheng
2015-12-01  9:36 ` [Qemu-devel] [PATCH 1/3] block: Don't wait serialising for non-COR read requests Fam Zheng
2015-12-01  9:54   ` Kevin Wolf [this message]
2015-12-01 10:26     ` Fam Zheng
2015-12-01 11:00       ` Kevin Wolf
2015-12-01  9:36 ` [Qemu-devel] [PATCH 2/3] iotests: Add "add_drive_raw" method Fam Zheng
2015-12-01  9:36 ` [Qemu-devel] [PATCH 3/3] iotests: Add regresion test case for write notifier assertion failure Fam Zheng
2015-12-03  6:50 ` [Qemu-devel] [PATCH 0/3] block: Fix assertion failure with before write notifier again Stefan Hajnoczi

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