From: Ingo Molnar <mingo@elte.hu>
To: George Anzinger <george@mvista.com>
Cc: Roman Zippel <zippel@linux-m68k.org>,
tglx@linutronix.de, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@osdl.org>,
johnstul@us.ibm.com, paulmck@us.ibm.com,
Christoph Hellwig <hch@infradead.org>,
oleg@tv-sign.ru, tim.bird@am.sony.com
Subject: Re: [PATCH] ktimers subsystem 2.6.14-rc2-kt5
Date: Tue, 4 Oct 2005 07:51:11 +0200 [thread overview]
Message-ID: <20051004055111.GA20208@elte.hu> (raw)
In-Reply-To: <4341E206.3090204@mvista.com>
* George Anzinger <george@mvista.com> wrote:
> > yeah, and that's an assumption that simplifies things on SMP
> > significantly. PIT on SMP systems for HRT is so gross that it's not
> > funny. If anyone wants to revive that notion, please do a separate
> > patch and make the case convincing enough ...
>
> Lets not talk about PIT, but, a lot of SMP platforms do NOT have per
> cpu timers. For those, it would seem having per cpu lists to handle
> the timer is not really reasonable.
frankly, such systems are rare, and are an afterthought at most. Think
about it: 8 CPUs and only one hres timer source? It cannot work nor
scale well.
i agree that they might eventually be handled (although i think we
shouldnt bother, all sane SMP designs have per-CPU timers), but we
definite wont design for them. What such an architecture has to do is to
provide the proper do_hr_timer_int() and arch_hrtimer_reprogram()
semantics, via locking around that timer source (naturally), and via
cross-CPU calls - as if they were per-CPU timers.
Ingo
next prev parent reply other threads:[~2005-10-04 5:50 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-28 20:43 [PATCH] ktimers subsystem 2.6.14-rc2-kt5 tglx
2005-09-28 23:59 ` Frank Sorenson
2005-09-29 0:50 ` Frank Sorenson
2005-09-29 0:56 ` john stultz
2005-09-29 1:05 ` Frank Sorenson
2005-09-29 1:10 ` john stultz
2005-09-29 6:53 ` Thomas Gleixner
2005-09-30 15:58 ` Frank Sorenson
2005-09-29 19:57 ` George Anzinger
2005-10-01 1:03 ` Roman Zippel
2005-10-01 11:22 ` Ingo Molnar
2005-10-04 1:59 ` George Anzinger
2005-10-04 5:51 ` Ingo Molnar [this message]
2005-10-10 12:42 ` Roman Zippel
2005-10-10 14:04 ` Ingo Molnar
2005-10-01 12:05 ` Thomas Gleixner
2005-10-10 17:22 ` Roman Zippel
2005-10-11 7:42 ` Thomas Gleixner
2005-10-12 22:36 ` Roman Zippel
2005-10-12 23:46 ` George Anzinger
2005-10-16 16:34 ` Roman Zippel
2005-10-16 19:26 ` Thomas Gleixner
2005-10-16 23:03 ` Roman Zippel
2005-10-17 7:59 ` Ingo Molnar
2005-10-17 8:26 ` Steven Rostedt
2005-10-17 9:29 ` Roman Zippel
2005-10-17 9:41 ` Ingo Molnar
2005-10-17 9:56 ` Andrew Morton
2005-10-17 11:00 ` Ingo Molnar
2005-10-17 16:25 ` Roman Zippel
2005-10-17 16:49 ` Tim Bird
2005-10-17 17:26 ` Steven Rostedt
2005-10-17 18:49 ` Roman Zippel
2005-10-17 19:19 ` Tim Bird
2005-10-17 19:48 ` Roman Zippel
2005-10-17 20:13 ` Ingo Molnar
2005-10-17 20:31 ` Roman Zippel
2005-10-18 8:46 ` Ingo Molnar
2005-10-18 23:52 ` Tim Bird
2005-10-19 0:03 ` George Anzinger
2005-10-19 1:58 ` Roman Zippel
2005-10-19 6:46 ` Ingo Molnar
2005-10-19 10:49 ` kernel/timer.c design (was: Re: ktimers subsystem) Ingo Molnar
2005-10-19 17:48 ` kernel/timer.c design Tim Bird
2005-10-19 18:00 ` Tim Bird
2005-10-19 19:04 ` Thomas Gleixner
2005-10-19 22:12 ` kernel/timer.c design (was: Re: ktimers subsystem) Roman Zippel
2005-10-19 11:40 ` [PATCH] ktimers subsystem 2.6.14-rc2-kt5 Ingo Molnar
2005-10-19 11:58 ` Ingo Molnar
2005-10-19 22:24 ` Roman Zippel
2005-10-17 20:09 ` Ingo Molnar
2005-10-17 20:55 ` Thomas Gleixner
2005-10-18 0:07 ` Roman Zippel
2005-10-18 1:03 ` George Anzinger
2005-10-19 1:26 ` Roman Zippel
2005-10-19 2:52 ` George Anzinger
2005-10-21 16:22 ` Roman Zippel
2005-10-23 18:17 ` George Anzinger
2005-10-27 20:23 ` Roman Zippel
2005-10-28 4:52 ` Steven Rostedt
2005-10-28 16:06 ` Roman Zippel
2005-10-17 16:33 ` Roman Zippel
2005-10-17 16:39 ` Ingo Molnar
2005-10-17 16:54 ` Roman Zippel
2005-10-17 17:35 ` Ingo Molnar
2005-10-17 9:54 ` Steven Rostedt
2005-10-04 1:55 ` George Anzinger
-- strict thread matches above, loose matches on Subject: below --
2005-10-17 18:38 linux
2005-10-17 19:04 ` Roman Zippel
2005-10-17 22:41 ` linux
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20051004055111.GA20208@elte.hu \
--to=mingo@elte.hu \
--cc=akpm@osdl.org \
--cc=george@mvista.com \
--cc=hch@infradead.org \
--cc=johnstul@us.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@tv-sign.ru \
--cc=paulmck@us.ibm.com \
--cc=tglx@linutronix.de \
--cc=tim.bird@am.sony.com \
--cc=zippel@linux-m68k.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.