lkml.org 
[lkml]   [2007]   [Jul]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] i386 CPA fix - do not free reserved pages
Right, there is a test missing, can you try this fix on top of my
x86_64 mm cpa cache flush fix ?


i386 CPA fix - do not free reserved pages

We have to use the same conditions found in change_page_attr in
global_tlb_flush regarding the conditions that leads to free the page.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---
arch/i386/mm/pageattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6-lttng/arch/i386/mm/pageattr.c
===================================================================
--- linux-2.6-lttng.orig/arch/i386/mm/pageattr.c 2007-07-03 13:25:48.000000000 -0400
+++ linux-2.6-lttng/arch/i386/mm/pageattr.c 2007-07-03 13:28:34.000000000 -0400
@@ -247,7 +247,7 @@
list_for_each_entry_safe(pg, next, &l, lru) {
clear_bit(PG_arch_1, &pg->flags);
list_del(&pg->lru);
- if (page_private(pg) != 0)
+ if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0)
continue;
ClearPagePrivate(pg);
__free_page(pg);

* Frederik Deweerdt (deweerdt@free.fr) wrote:
> On Tue, Jul 03, 2007 at 11:37:47AM -0400, Mathieu Desnoyers wrote:
> > Hi Alan,
> >
> > I already sent a fix to Andrew and Andi for this (hrm, forget to CC
> > lkml on the original message):
> >
> >
> > x86_64 mm cpa cache flush fix
> >
> > X86_64 and i386 cpa cache flush fix:
> >
> > list_del the deferred list entries to poison their pointers.
> > clear the flag for every page put in the list.
> >
> Hi Mathieu,
>
> I've tried the patch on rc6-mm1, but it doesn't seem to fix the
> problem. From what I understood, the bad_page() is called on PG_reserved
> being set (flags:0x00000400), not the lru pointer being not NULL or
> PG_arch_1 being set.
>
> Regards,
> Frederik
>
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> > CC: Andi Kleen <ak@suse.de>
> [...]
> > flush_map(&l);
> > list_for_each_entry_safe(pg, next, &l, lru) {
> > + clear_bit(PG_arch_1, &pg->flags);
> > + list_del(&pg->lru);
> > if (page_private(pg) != 0)
> > continue;
> > ClearPagePrivate(pg);
> > - clear_bit(PG_arch_1, &pg->flags);
> > __free_page(pg);
> > }
> > }
> [...]
> > * Alan Cox (alan@lxorguk.ukuu.org.uk) wrote:
> > > X86 32bit with lots of debug turned on I get this:
> [...]
> > > Bad page state in process 'swapper'
> > > page:c10000c0 flags:0x00000400 mapping:00000000 mapcount:0 count:0
> > > Trying to fix it up, but a reboot is needed
> > > Backtrace:
> > > [<c024589c>] bad_page+0x6c/0x100
> > > [<c024648d>] free_hot_cold_page+0x5d/0x140
> > > [<c02116c2>] global_flush_tlb+0x112/0x130
> > > [<c020102d>] init_post+0xd/0xe0
> > > [<c047c876>] kernel_init+0x216/0x220
> > > [<c0214c50>] schedule_tail+0x0/0xe0
> > > [<c047c660>] kernel_init+0x0/0x220
> > > [<c047c660>] kernel_init+0x0/0x220
> > > [<c0204227>] kernel_thread_helper+0x7/0x10
> > > =======================
> > > Hexdump:
> > > 000: 00 06 00 00 01 00 00 00 ff ff ff ff 0f 00 00 00
> > > 010: 00 00 00 00 00 00 00 00 78 00 00 c1 b8 00 00 c1
> > > 020: 00 06 00 00 01 00 00 00 ff ff ff ff a7 03 00 00
> > > 030: 00 00 00 00 00 00 00 00 98 00 00 c1 d8 00 00 c1
> > > 040: 00 04 00 00 00 00 00 00 ff ff ff ff 00 00 00 00
> > > 050: 00 00 00 00 00 00 00 00 b8 00 00 c1 f8 00 00 c1
> > > 060: 00 06 00 00 01 00 00 00 ff ff ff ff 00 04 00 00
> > > 070: 00 00 00 00 00 00 00 00 d8 00 00 c1 18 01 00 c1
> > > 080: 00 06 00 00 01 00 00 00 ff ff ff ff 9c 03 00 00
> > > 090: 00 00 00 00 00 00 00 00 f8 00 00 c1 38 01 00 c1
> > > 0a0: 00 06 00 00 01 00 00 00 ff ff ff ff 00 04 00 00
> > > 0b0: 00 00 00 00 00 00 00 00 18 01 00 c1 58 01 00 c1
> > > -
> > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > > Please read the FAQ at http://www.tux.org/lkml/
> > >
> >
> > --
> > Mathieu Desnoyers
> > Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
> > OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at http://www.tux.org/lkml/
> >
>

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-07-03 19:35    [W:0.023 / U:1.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site