From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>,
Andi Kleen <ak@suse.de>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: preempt bug in set_pmd_pfn?
Date: Tue, 04 Mar 2008 13:13:43 -0800 [thread overview]
Message-ID: <47CDBB87.8090906@goop.org> (raw)
I think set_pmd_pfn, which is only called by __set_fixmap, might have a
preempt bug in it.
It can be executed with preemption enabled, but what if it gets preempted
set_pmd(pmd, pfn_pmd(pfn, flags));
/*
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
>here<
__flush_tlb_one(vaddr);
}
?
Won't this leave a stale tlb on the old processor?
I noticed this because the Xen tlb flushing code effectively has a
smp_processor_id(), which provokes a warning when preemption is
enabled. It seems to me that it never makes sense to be doing a tlb
flush unless you know which processor you're actually running on...
J
next reply other threads:[~2008-03-04 21:19 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-04 21:13 Jeremy Fitzhardinge [this message]
2008-03-04 21:28 ` preempt bug in set_pmd_pfn? Ingo Molnar
2008-03-04 21:27 ` Jeremy Fitzhardinge
2008-03-05 6:48 ` Ingo Molnar
2008-03-05 14:29 ` Hugh Dickins
2008-03-05 16:48 ` Jeremy Fitzhardinge
2008-03-05 17:38 ` Hugh Dickins
2008-03-05 19:18 ` Jeremy Fitzhardinge
2008-03-05 20:40 ` Hugh Dickins
2008-03-06 12:52 ` Ingo Molnar
2008-03-06 18:19 ` Jeremy Fitzhardinge
2008-03-05 16:45 ` Jeremy Fitzhardinge
2008-03-05 0:06 ` Andi Kleen
2008-03-05 0:07 ` Jeremy Fitzhardinge
2008-03-05 0:16 ` Andi Kleen
2008-03-05 0:19 ` Jeremy Fitzhardinge
2008-03-05 1:28 ` Andi Kleen
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