From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 6083C5F0001 for ; Tue, 7 Apr 2009 20:29:18 -0400 (EDT) Date: Tue, 7 Apr 2009 19:29:41 -0500 From: Russ Anderson Subject: Re: [PATCH] [2/16] POISON: Add page flag for poisoned pages Message-ID: <20090408002941.GA14041@sgi.com> Reply-To: Russ Anderson References: <20090407509.382219156@firstfloor.org> <20090407150958.BA68F1D046D@basil.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090407150958.BA68F1D046D@basil.firstfloor.org> Sender: owner-linux-mm@kvack.org To: Andi Kleen Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, rja@sgi.com List-ID: On Tue, Apr 07, 2009 at 05:09:58PM +0200, Andi Kleen wrote: > > Poisoned pages need special handling in the VM and shouldn't be touched > again. This requires a new page flag. Define it here. > > The page flags wars seem to be over, so it shouldn't be a problem > to get a new one. I hope. > > Signed-off-by: Andi Kleen > > --- > include/linux/page-flags.h | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > Index: linux/include/linux/page-flags.h > =================================================================== > --- linux.orig/include/linux/page-flags.h 2009-04-07 16:39:27.000000000 +0200 > +++ linux/include/linux/page-flags.h 2009-04-07 16:39:39.000000000 +0200 > @@ -51,6 +51,9 @@ > * PG_buddy is set to indicate that the page is free and in the buddy system > * (see mm/page_alloc.c). > * > + * PG_poison indicates that a page got corrupted in hardware and contains > + * data with incorrect ECC bits that triggered a machine check. Accessing is > + * not safe since it may cause another machine check. Don't touch! > */ > > /* > @@ -104,6 +107,9 @@ > #ifdef CONFIG_IA64_UNCACHED_ALLOCATOR > PG_uncached, /* Page has been mapped as uncached */ > #endif > +#ifdef CONFIG_MEMORY_FAILURE Is it necessary to have this under CONFIG_MEMORY_FAILURE? > + PG_poison, /* poisoned page. Don't touch */ > +#endif > __NR_PAGEFLAGS, > > /* Filesystems */ > @@ -273,6 +279,14 @@ > PAGEFLAG_FALSE(Uncached) > #endif > > +#ifdef CONFIG_MEMORY_FAILURE > +PAGEFLAG(Poison, poison) > +#define __PG_POISON (1UL << PG_poison) > +#else > +PAGEFLAG_FALSE(Poison) > +#define __PG_POISON 0 > +#endif > + > static inline int PageUptodate(struct page *page) > { > int ret = test_bit(PG_uptodate, &(page)->flags); > @@ -403,7 +417,7 @@ > 1 << PG_private | 1 << PG_private_2 | \ > 1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \ > 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \ > - __PG_UNEVICTABLE | __PG_MLOCKED) > + __PG_POISON | __PG_UNEVICTABLE | __PG_MLOCKED) > > /* > * Flags checked when a page is prepped for return by the page allocator. > -- > 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/ -- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@sgi.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org