netdev - Re: [PATCH net v2 2/2] vhost_net: fix high cpu load when sendmsg fails

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <482e71e6-2c85-346f-d7f9-10db6a5c716b@redhat.com>
Date:   Thu, 17 Dec 2020 11:19:57 +0800
From:   Jason Wang <jasowang@...hat.com>
To:     "Michael S. Tsirkin" <mst@...hat.com>,
        wangyunjian <wangyunjian@...wei.com>
Cc:     netdev@...r.kernel.org, willemdebruijn.kernel@...il.com,
        virtualization@...ts.linux-foundation.org,
        jerry.lilijun@...wei.com, chenchanghu@...wei.com,
        xudingke@...wei.com, brian.huangbin@...wei.com
Subject: Re: [PATCH net v2 2/2] vhost_net: fix high cpu load when sendmsg
 fails


On 2020/12/16 下午5:23, Michael S. Tsirkin wrote:
> On Wed, Dec 16, 2020 at 04:20:37PM +0800, wangyunjian wrote:
>> From: Yunjian Wang<wangyunjian@...wei.com>
>>
>> Currently we break the loop and wake up the vhost_worker when
>> sendmsg fails. When the worker wakes up again, we'll meet the
>> same error. This will cause high CPU load. To fix this issue,
>> we can skip this description by ignoring the error. When we
>> exceeds sndbuf, the return value of sendmsg is -EAGAIN. In
>> the case we don't skip the description and don't drop packet.
> Question: with this patch, what happens if sendmsg is interrupted by a signal?


Since we use MSG_DONTWAIT, we don't need to care about signal I think.

Thanks


>
>