Re: [rfc] direct IO submission and completion scalability issues

!MAILaRCHIVE_VOTE_RePLACE
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: Jens Axboe <jens.axboe@...>
Cc: Nick Piggin <npiggin@...>, Siddha, Suresh B <suresh.b.siddha@...>, <linux-kernel@...>, <arjan@...>, <mingo@...>, <ak@...>, <andrea@...>, <clameter@...>, <akpm@...>, <andrew.vasquez@...>, <willy@...>, Zach Brown <zach.brown@...>
Date: Monday, February 4, 2008 - 6:28 pm

On Mon, 2008-02-04 at 05:33 -0500, Jens Axboe wrote:

Sorry, late to the party ... it went to my steeleye address, not my
current one.

Could you try re-running the tests with a low queue depth (say around 8)
and the card interrupt bound to a single CPU.

The reason for asking you to do this is that it should emulate almost
precisely what you're looking for:  The submit path will be picked up in
the SCSI softirq where the queue gets run, so you should find that all
submit and returns happen on a single CPU, so everything gets cache hot
there.

James

p.s. if everyone could also update my email address to the
hansenpartnership one, the people at steeleye who monitor my old email
account would be grateful.

--
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
[rfc] direct IO submission and completion scalability issues, Siddha, Suresh B, (Fri Jul 27, 9:21 pm)
Re: [rfc] direct IO submission and completion scalability is..., James Bottomley, (Mon Feb 4, 6:28 pm)
Re: [rfc] direct IO submission and completion scalability is..., Christoph Lameter, (Mon Jul 30, 2:20 pm)