From: Bart Van Assche <bvanassche@acm.org>
To: James Bottomley <James.Bottomley@HansenPartnership.com>,
Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>,
Nicholas Bellinger <nab@linux-iscsi.org>,
linux-scsi@vger.kernel.org
Subject: Re: Proposal for a scalable SCSI midlayer
Date: Wed, 26 Feb 2014 11:59:56 +0100 [thread overview]
Message-ID: <530DC92C.5070603@acm.org> (raw)
In-Reply-To: <1393186218.9743.3.camel@dabdike>
On 02/23/14 21:10, James Bottomley wrote:
> Right ... my ideal here if we can achieve it would be lockless threaded
> models, where we could make guarantees like single thread of execution
> per command, so all command state could be lockless.
This approach sounds interesting but could be challenging to implement.
With this approach it would no longer be safe to access the SCSI command
state from interrupt nor from tasklet context. That means that the I/O
completion path would have to be modified such that instead of using an
IPI to invoke a tasklet at the CPU that submitted the SCSI command a new
mechanism would have to be used that causes the I/O completion code to
run directly on the context of the thread that submitted the SCSI command.
Bart.
next prev parent reply other threads:[~2014-02-26 10:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-05 12:39 Proposal for a scalable SCSI midlayer Christoph Hellwig
2014-02-23 20:10 ` James Bottomley
2014-02-24 4:25 ` Christoph Hellwig
2014-02-26 10:59 ` Bart Van Assche [this message]
2014-02-26 17:12 ` James Bottomley
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