From: "Xiaoliang \(David\) Wei" <weixl@caltech.edu>
To: "jamal" <hadi@cyberus.ca>, "Andi Kleen" <ak@suse.de>
Cc: "Ben Greear" <greearb@candelatech.com>,
"Cheng Jin" <chengjin@cs.caltech.edu>,
"Cheng Hu" <chenghu@cs.caltech.edu>,
"Steven Low" <slow@cs.caltech.edu>, <netdev@oss.sgi.com>
Subject: Re: packet re-ordering on SMP machines.
Date: Tue, 27 Aug 2002 12:43:02 -0700 [thread overview]
Message-ID: <002701c24e01$f59b6190$8900a8c0@weixl> (raw)
In-Reply-To: Pine.GSO.4.30.0208270803520.6895-100000@shell.cyberus.ca
> >
> > That is because of the lock it takes. Locks are always slow.
>
> xtime_lock?
I guess so, after looked at do_gettimeofday
>
> > Possibilities:
> >
> > - Ignore the problem and switch back to gettimeoffset again
>
> Is it safe to call gettimeoffset without the lock?
What's the possible danger to ignore the lock? Can I read the xtime
directly?
>
> > - Switch to gettimeoffset but add some correction step for the unlikely
> > case that someone wants the timestamp from user space
> > (would be my prefered solution)
> > - Implement lockless gettimeofday like x86-64 or sparc
> > (good one too, but likely slower than last)
>
>
> ia64 seems to also have the lock.
>
> cheers,
> jamal
>
>
>
>
next prev parent reply other threads:[~2002-08-27 19:43 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.GSO.4.30.0208251149320.29461-100000@shell.cyberus.ca>
2002-08-25 18:32 ` packet re-ordering on SMP machines Ben Greear
2002-08-26 0:52 ` jamal
2002-08-26 4:34 ` Ben Greear
2002-08-26 11:20 ` jamal
2002-08-26 23:03 ` Xiaoliang (David) Wei
2002-08-26 23:20 ` Ben Greear
2002-08-27 10:59 ` jamal
2002-08-27 11:12 ` Andi Kleen
2002-08-27 12:05 ` jamal
2002-08-27 12:20 ` Andi Kleen
2002-08-27 13:06 ` kuznet
2002-08-27 13:13 ` Andi Kleen
2002-08-27 13:24 ` kuznet
2002-09-15 8:42 ` Harald Welte
2002-09-15 21:55 ` Alexey Kuznetsov
2002-08-27 17:22 ` Cheng Jin
2002-08-27 17:33 ` Andi Kleen
2002-08-27 19:43 ` Xiaoliang (David) Wei [this message]
2002-08-25 15:56 jamal
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