From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Ian Jackson <Ian.Jackson@eu.citrix.com>, Wei Liu <wei.liu2@citrix.com>
Cc: Xen-devel <xen-devel@lists.xenproject.org>,
Ian Campbell <ian.campbell@citrix.com>
Subject: Re: [PATCH] cxenstored: correct calculation of data/space in the ring
Date: Mon, 16 Nov 2015 18:06:00 +0000 [thread overview]
Message-ID: <564A1B08.5080900@citrix.com> (raw)
In-Reply-To: <22090.6649.488665.395378@mariner.uk.xensource.com>
On 16/11/15 18:01, Ian Jackson wrote:
> Wei Liu writes ("[PATCH] cxenstored: correct calculation of data/space in the ring"):
>> The cxenstored implementation can't handle cross ring boundary read and
>> write. It gets aways with buggy behaviour because upper layer won't
>> sleep when short-write or short-read occurs.
> I don't understand why you think this is a bug.
It is exactly the same bug as I fixed in c/s 8a2c11f8
The short reads/writes themselves aren't inherently a problem. They are
genuine signals that the server should wait for the client to
produce/consume more data.
However, the low level functions erroneously return a short read/write
when hitting the ring boundary when there is actually more space/data.
This causes a protocol stall as the server incorrectly believes that the
client has the next action to perform.
~Andrew
next prev parent reply other threads:[~2015-11-16 18:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-16 12:53 [PATCH] cxenstored: correct calculation of data/space in the ring Wei Liu
2015-11-16 18:01 ` Ian Jackson
2015-11-16 18:06 ` Andrew Cooper [this message]
2015-11-16 18:09 ` Ian Jackson
2015-11-16 18:36 ` Wei Liu
2015-11-24 16:21 ` Ian Campbell
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