From: David Laight <David.Laight@ACULAB.COM>
To: 'Praveen Kumar' <kumarpraveen@linux.microsoft.com>,
Saurabh Sengar <ssengar@linux.microsoft.com>,
"kys@microsoft.com" <kys@microsoft.com>,
"haiyangz@microsoft.com" <haiyangz@microsoft.com>,
"sthemmin@microsoft.com" <sthemmin@microsoft.com>,
"wei.liu@kernel.org" <wei.liu@kernel.org>,
"decui@microsoft.com" <decui@microsoft.com>,
"jejb@linux.ibm.com" <jejb@linux.ibm.com>,
"martin.petersen@oracle.com" <martin.petersen@oracle.com>,
"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"ssengar@microsoft.com" <ssengar@microsoft.com>,
"mikelley@microsoft.com" <mikelley@microsoft.com>
Subject: RE: [PATCH] scsi: storvsc: Prevent running tasklet for long
Date: Wed, 6 Jul 2022 11:09:43 +0000 [thread overview]
Message-ID: <a9af8d8d5ee24d19a87c3353a4e8941d@AcuMS.aculab.com> (raw)
In-Reply-To: <b4fea161-41c5-a03e-747b-316c74eb986c@linux.microsoft.com>
From: Praveen Kumar
> Sent: 06 July 2022 10:15
>
> On 05-07-2022 21:02, Saurabh Sengar wrote:
> > There can be scenarios where packets in ring buffer are continuously
> > getting queued from upper layer and dequeued from storvsc interrupt
> > handler, such scenarios can hold the foreach_vmbus_pkt loop (which is
> > executing as a tasklet) for a long duration. Theoretically its possible
> > that this loop executes forever. Add a condition to limit execution of
> > this tasklet for finite amount of time to avoid such hazardous scenarios.
Does this really make much difference?
I'd guess the tasklet gets immediately rescheduled as soon as
the upper layer queues another packet?
Or do you get a different 'bug' where it is never woken again
because the ring is stuck full?
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-07-06 11:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-05 15:32 [PATCH] scsi: storvsc: Prevent running tasklet for long Saurabh Sengar
2022-07-05 17:39 ` Michael Kelley (LINUX)
2022-07-06 9:14 ` Praveen Kumar
2022-07-06 9:53 ` Saurabh Singh Sengar
2022-07-06 14:29 ` Praveen Kumar
2022-07-06 11:09 ` David Laight [this message]
2022-07-08 10:42 ` Saurabh Singh Sengar
2022-07-08 12:41 ` David Laight
2022-07-08 12:43 ` Jeremi Piotrowski
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