| Message ID | 20140505.162004.1797345518474659123.davem@davemloft.net |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
From: David Miller <davem@davemloft.net> Date: Mon, 05 May 2014 16:20:04 -0400 (EDT) > > If freelist_idx_t is a byte, SLAB_OBJ_MAX_NUM should be 255 not 256, > and likewise if freelist_idx_t is a short, then it should be 65535 not > 65536. > > Fixes: a41adfa ("slab: introduce byte sized index for the freelist of a slab") > Signed-off-by: David S. Miller <davem@davemloft.net> > --- > > This was leading to all kinds of random crashes on sparc64 where PAGE_SIZE > is 8192. One problem shown was that if spinlock debugging was enabled, > we'd get deadlocks in copy_pte_range() or do_wp_page() with the same cpu > already holding a lock it shouldn't hold, or the lock belonging to a > completely unrelated process. It turns out that after some more testing, I'm still getting spinlock debugging problems with this fix applied. The change is still very much correct I think, however. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, May 05, 2014 at 04:57:56PM -0400, David Miller wrote: > From: David Miller <davem@davemloft.net> > Date: Mon, 05 May 2014 16:20:04 -0400 (EDT) > > > > > If freelist_idx_t is a byte, SLAB_OBJ_MAX_NUM should be 255 not 256, > > and likewise if freelist_idx_t is a short, then it should be 65535 not > > 65536. > > > > Fixes: a41adfa ("slab: introduce byte sized index for the freelist of a slab") > > Signed-off-by: David S. Miller <davem@davemloft.net> > > --- > > > > This was leading to all kinds of random crashes on sparc64 where PAGE_SIZE > > is 8192. One problem shown was that if spinlock debugging was enabled, > > we'd get deadlocks in copy_pte_range() or do_wp_page() with the same cpu > > already holding a lock it shouldn't hold, or the lock belonging to a > > completely unrelated process. > > It turns out that after some more testing, I'm still getting spinlock > debugging problems with this fix applied. > > The change is still very much correct I think, however. There is a related patch in this area which I think is not yet applied. See: https://lkml.org/lkml/2014/4/18/28 Maybe this is realted. Sam -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Sam Ravnborg <sam@ravnborg.org> Date: Mon, 5 May 2014 23:05:07 +0200 > On Mon, May 05, 2014 at 04:57:56PM -0400, David Miller wrote: >> From: David Miller <davem@davemloft.net> >> Date: Mon, 05 May 2014 16:20:04 -0400 (EDT) >> >> > >> > If freelist_idx_t is a byte, SLAB_OBJ_MAX_NUM should be 255 not 256, >> > and likewise if freelist_idx_t is a short, then it should be 65535 not >> > 65536. >> > >> > Fixes: a41adfa ("slab: introduce byte sized index for the freelist of a slab") >> > Signed-off-by: David S. Miller <davem@davemloft.net> >> > --- >> > >> > This was leading to all kinds of random crashes on sparc64 where PAGE_SIZE >> > is 8192. One problem shown was that if spinlock debugging was enabled, >> > we'd get deadlocks in copy_pte_range() or do_wp_page() with the same cpu >> > already holding a lock it shouldn't hold, or the lock belonging to a >> > completely unrelated process. >> >> It turns out that after some more testing, I'm still getting spinlock >> debugging problems with this fix applied. >> >> The change is still very much correct I think, however. > > There is a related patch in this area which I think is not yet applied. > > See: https://lkml.org/lkml/2014/4/18/28 > > Maybe this is realted. Thanks, I'm testing with that patch added as well. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: David Miller <davem@davemloft.net> Date: Mon, 05 May 2014 17:08:55 -0400 (EDT) > From: Sam Ravnborg <sam@ravnborg.org> > Date: Mon, 5 May 2014 23:05:07 +0200 > >> On Mon, May 05, 2014 at 04:57:56PM -0400, David Miller wrote: >>> From: David Miller <davem@davemloft.net> >>> Date: Mon, 05 May 2014 16:20:04 -0400 (EDT) >>> >>> > >>> > If freelist_idx_t is a byte, SLAB_OBJ_MAX_NUM should be 255 not 256, >>> > and likewise if freelist_idx_t is a short, then it should be 65535 not >>> > 65536. >>> > >>> > Fixes: a41adfa ("slab: introduce byte sized index for the freelist of a slab") >>> > Signed-off-by: David S. Miller <davem@davemloft.net> >>> > --- >>> > >>> > This was leading to all kinds of random crashes on sparc64 where PAGE_SIZE >>> > is 8192. One problem shown was that if spinlock debugging was enabled, >>> > we'd get deadlocks in copy_pte_range() or do_wp_page() with the same cpu >>> > already holding a lock it shouldn't hold, or the lock belonging to a >>> > completely unrelated process. >>> >>> It turns out that after some more testing, I'm still getting spinlock >>> debugging problems with this fix applied. >>> >>> The change is still very much correct I think, however. >> >> There is a related patch in this area which I think is not yet applied. >> >> See: https://lkml.org/lkml/2014/4/18/28 >> >> Maybe this is realted. > > Thanks, I'm testing with that patch added as well. I can confirm that this fixes my problems completely. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, May 5, 2014 at 8:25 PM, David Miller <davem@davemloft.net> wrote: > >> Sam Ravnborg <sam@ravnborg.org> wrote: >>> >>> There is a related patch in this area which I think is not yet applied. >>> >>> See: https://lkml.org/lkml/2014/4/18/28 >>> >>> Maybe this is related. >> >> Thanks, I'm testing with that patch added as well. > > I can confirm that this fixes my problems completely. Ugh. That patch has been out two weeks already. Pekka? I guess I'll apply both patches directly. Linus -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, May 5, 2014 at 8:32 PM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > > I guess I'll apply both patches directly. Applied and pushed out. Davem, I hope this means current -git works for you on sparc64 again? Linus -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Linus Torvalds <torvalds@linux-foundation.org> Date: Mon, 5 May 2014 20:46:32 -0700 > On Mon, May 5, 2014 at 8:32 PM, Linus Torvalds > <torvalds@linux-foundation.org> wrote: >> >> I guess I'll apply both patches directly. > > Applied and pushed out. Davem, I hope this means current -git works > for you on sparc64 again? Yes it absoultely should, and I'll double check to make sure. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, May 6, 2014 at 6:32 AM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > On Mon, May 5, 2014 at 8:25 PM, David Miller <davem@davemloft.net> wrote: >> >>> Sam Ravnborg <sam@ravnborg.org> wrote: >>>> >>>> There is a related patch in this area which I think is not yet applied. >>>> >>>> See: https://lkml.org/lkml/2014/4/18/28 >>>> >>>> Maybe this is related. >>> >>> Thanks, I'm testing with that patch added as well. >> >> I can confirm that this fixes my problems completely. > > Ugh. That patch has been out two weeks already. Pekka? Sorry, I missed that completely. > I guess I'll apply both patches directly. Thanks! -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mm/slab.c b/mm/slab.c index 388cb1a..37de3a7 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -166,7 +166,7 @@ typedef unsigned char freelist_idx_t; typedef unsigned short freelist_idx_t; #endif -#define SLAB_OBJ_MAX_NUM (1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) +#define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1) /* * true if a page was allocated from pfmemalloc reserves for network-based
If freelist_idx_t is a byte, SLAB_OBJ_MAX_NUM should be 255 not 256, and likewise if freelist_idx_t is a short, then it should be 65535 not 65536. Fixes: a41adfa ("slab: introduce byte sized index for the freelist of a slab") Signed-off-by: David S. Miller <davem@davemloft.net> --- This was leading to all kinds of random crashes on sparc64 where PAGE_SIZE is 8192. One problem shown was that if spinlock debugging was enabled, we'd get deadlocks in copy_pte_range() or do_wp_page() with the same cpu already holding a lock it shouldn't hold, or the lock belonging to a completely unrelated process. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html