Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932266AbVKULwK (ORCPT ); Mon, 21 Nov 2005 06:52:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932268AbVKULwJ (ORCPT ); Mon, 21 Nov 2005 06:52:09 -0500 Received: from ns2.suse.de ([195.135.220.15]:62881 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S932266AbVKULwI (ORCPT ); Mon, 21 Nov 2005 06:52:08 -0500 Date: Mon, 21 Nov 2005 12:52:02 +0100 Message-ID: From: Takashi Iwai To: Hugh Dickins Cc: Lee Revell , Miles Lane , Andrew Morton , LKML , alsa-devel Subject: Re: 2.6.15-rc1-mm2 -- Bad page state at free_hot_cold_page (in process 'aplay', page c18eef30) In-Reply-To: References: <1132510467.6874.144.camel@mindpipe> User-Agent: Wanderlust/2.12.0 (Your Wildest Dreams) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (=?ISO-8859-4?Q?Sanj=F2?=) APEL/10.6 MULE XEmacs/21.5 (beta18) (chestnut) (+CVS-20041021) (i386-suse-linux) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4813 Lines: 123 Hi Hugh, At Sun, 20 Nov 2005 19:35:57 +0000 (GMT), Hugh Dickins wrote: > > On Sun, 20 Nov 2005, Lee Revell wrote: > > (Added alsa-devel to cc:) > > > > Will this change have any ill effects on older kernels? > > I think not (except 2.6.5 and earlier didn't define __GFP_COMP). Sorry, I still don't figure out how __GFP_COMP solved this problem. Could you enlighten me a bit? Isn't it needed for dma_alloc_coherent() (for i386, particularly), too? dma_alloc_coherent() also gets pages with __get_free_pages(). Also, I think we can remove all Set/ClearPageReserved() in memalloc.c now. It was there just for mmap... > > If not we should fix it in the ALSA tree right? > > Probably, but I'm no authority on the ALSA tree. We'd need to add a dummy definition of __GFP_COMP for older kenels in alsa-driver tree. But that's all. > And suggest you wait a bit, since I haven't yet signed off on the > patch that piece will be a part of. > > And what about the patch at the bottom (which I had CC'ed to Karsten > Wiese), is that part of the ALSA tree too? That case isn't so easy: > the get_page makes a difference, and probably it was right not to do > it before, yet strange it was the only nopage in the tree which didn't > get_page. In the ealier version, get_page() in sound/pcm_native.c was checked with "if (! PageReserved(page))". Since the pages were always reserved, get_page was never called indeed. (IIRC, the check was introduced to avoid crash with anon page or so.) usx2y driver was added later, so it didn't have unneeded get_page(). thanks, Takashi > > Hugh > > > Lee > > > > On Sun, 2005-11-20 at 08:05 +0000, Hugh Dickins wrote: > > > On Sat, 19 Nov 2005, Miles Lane wrote: > > > > [17179671.700000] Bad page state at free_hot_cold_page (in process > > > > 'aplay', page c18eef30) > > > > [17179671.700000] flags:0x80000414 mapping:00000000 mapcount:0 count:0 > > > > > > Please let me know if it's not fixed by: > > > > > > --- 2.6.15-rc1-mm2/sound/core/memalloc.c 2005-11-12 09:01:28.000000000 +0000 > > > +++ linux/sound/core/memalloc.c 2005-11-19 19:03:32.000000000 +0000 > > > @@ -197,6 +197,7 @@ void *snd_malloc_pages(size_t size, gfp_ > > > > > > snd_assert(size > 0, return NULL); > > > snd_assert(gfp_flags != 0, return NULL); > > > + gfp_flags |= __GFP_COMP; /* compound page lets parts be mapped */ > > > pg = get_order(size); > > > if ((res = (void *) __get_free_pages(gfp_flags, pg)) != NULL) { > > > mark_pages(virt_to_page(res), pg); > > > @@ -241,6 +242,7 @@ static void *snd_malloc_dev_pages(struct > > > snd_assert(dma != NULL, return NULL); > > > pg = get_order(size); > > > gfp_flags = GFP_KERNEL > > > + | __GFP_COMP /* compound page lets parts be mapped */ > > > | __GFP_NORETRY /* don't trigger OOM-killer */ > > > | __GFP_NOWARN; /* no stack trace print - this call is non-critical */ > > > res = dma_alloc_coherent(dev, PAGE_SIZE << pg, dma, gfp_flags); > > Karsten Wiese > [PATCH 03/11] unpaged: sound nopage get_page > > Something noticed when studying use of VM_RESERVED in different drivers: > snd_usX2Y_hwdep_pcm_vm_nopage omitted to get_page: fixed. > > And how did this work before? Aargh! That nopage is returning a page > from within a buffer allocated by snd_malloc_pages, which allocates a > high-order page, then does SetPageReserved on each 0-order page within. > > That would have worked in 2.6.14, because when the area was unmapped, > PageReserved inhibited put_page. 2.6.15-rc1 removed that inhibition > (while leaving ineffective PageReserveds around for now), but it hasn't > caused trouble because.. we've not been freeing from VM_RESERVED at all. > > Signed-off-by: Hugh Dickins > --- > > sound/usb/usx2y/usx2yhwdeppcm.c | 1 + > 1 files changed, 1 insertion(+) > > --- unpaged02/sound/usb/usx2y/usx2yhwdeppcm.c 2005-11-12 09:01:30.000000000 +0000 > +++ unpaged03/sound/usb/usx2y/usx2yhwdeppcm.c 2005-11-17 15:10:34.000000000 +0000 > @@ -691,6 +691,7 @@ static struct page * snd_usX2Y_hwdep_pcm > snd_assert((offset % PAGE_SIZE) == 0, return NOPAGE_OOM); > vaddr = (char*)((usX2Ydev_t*)area->vm_private_data)->hwdep_pcm_shm + offset; > page = virt_to_page(vaddr); > + get_page(page); > > if (type) > *type = VM_FAULT_MINOR; > - > 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/ > - 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/