From: David Mosberger-Tang <David.Mosberger@acm.org>
To: mingo@elte.hu, "Luck, Tony" <tony.luck@intel.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [patch] sched: unlocked context-switches
Date: Fri, 08 Apr 2005 23:32:45 -0700 [thread overview]
Message-ID: <ugoecowjci.fsf@panda.mostang.com> (raw)
In-Reply-To: <3R6Ir-89Y-23@gated-at.bofh.it> (Tony Luck's message of "Fri, 08 Apr 2005 20:50:11 +0200")
> Tony:
>> Ingo:
>> tested on x86, and all other arches should work as well, but if an
>> architecture has irqs-off assumptions in its switch_to() logic it
>> might break. (I havent found any but there may such assumptions.)
> The ia64_switch_to() code includes a section that can change a
> pinned MMU mapping (when the stack for the new process is in a
> different granule from the stack for the old process). The code
> beyond the ".map" label in arch/ia64/kernel/entry.S includes the
> comment:
Also, there was a nasty dead-lock that could trigger if the
context-switch was interrupted by a TLB flush IPI. I don't remember
the details offhand, but I'm pretty sure it had to do with
switch_mm(), so I suspect it may not be enough to disable irqs just
for ia64_switch_to(). Tread with care!
--david
next parent reply other threads:[~2005-04-09 6:32 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <3R6Ir-89Y-23@gated-at.bofh.it>
2005-04-09 6:32 ` David Mosberger-Tang [this message]
2005-04-09 7:07 ` [patch] sched: unlocked context-switches Ingo Molnar
2005-04-09 7:15 ` David Mosberger
2005-04-09 22:58 ` David S. Miller
2005-04-10 6:43 ` Ingo Molnar
2005-04-12 1:06 ` David Mosberger
2005-04-12 2:12 ` Nick Piggin
2005-04-12 17:14 ` David Mosberger
2005-04-13 3:26 ` Nick Piggin
2005-04-12 6:42 ` Ingo Molnar
2005-04-12 17:15 ` David Mosberger
2005-04-08 18:38 Luck, Tony
2005-04-09 4:38 ` Ingo Molnar
2005-04-09 6:28 ` Nick Piggin
2005-04-09 6:55 ` Ingo Molnar
2005-04-09 7:11 ` Nick Piggin
2005-04-09 9:22 ` Benjamin Herrenschmidt
2005-04-09 22:46 ` David S. Miller
2005-04-10 7:23 ` Richard Henderson
-- strict thread matches above, loose matches on Subject: below --
2005-04-08 12:16 Ingo Molnar
2005-04-29 9:09 ` Andrew Morton
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