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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Open Source <opensource3141@yahoo.com>
Cc: linux-usb-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: USB performance bug since kernel 2.6.13 (CRITICAL???)
Date: Sat, 14 Oct 2006 01:24:52 +0100	[thread overview]
Message-ID: <1160785492.25218.96.camel@localhost.localdomain> (raw)
In-Reply-To: <20061013233024.5786.qmail@web58107.mail.re3.yahoo.com>

Ar Gwe, 2006-10-13 am 16:30 -0700, ysgrifennodd Open Source:
> There is an ioctl that is waiting for the URB to be reaped.
> I am almost certain it is this syscall that is taking 4 ms (as
> opposed to 1 ms with CONFIG_HZ=1000).

What does strace say about it ? This is measurable not speculation.

> Will the first piece of code wake up immediately or only after the
> next HZ timeslice?  If it is the latter, which is what I am starting to

It depends if there are other things running and on their priority
relative to you.



  reply	other threads:[~2006-10-13 23:58 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-13 23:30 USB performance bug since kernel 2.6.13 (CRITICAL???) Open Source
2006-10-14  0:24 ` Alan Cox [this message]
2006-10-14  2:11   ` [linux-usb-devel] " Alan Stern
  -- strict thread matches above, loose matches on Subject: below --
2006-10-14 16:33 Open Source
2006-10-13 19:31 Open Source
2006-10-12 20:56 Open Source
2006-10-12 21:26 ` Lee Revell
2006-10-13 12:12   ` Ed Tomlinson
2006-10-12 20:05 Open Source
2006-10-12 20:19 ` Lee Revell
2006-10-12 19:33 Open Source
2006-10-12 19:55 ` Lee Revell
2006-10-12 19:21 Open Source

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