On Tuesday, 22 of April 2008, Paul E. McKenney wrote: > On Tue, Apr 22, 2008 at 12:26:04AM +0200, Jiri Slaby wrote: > > On 04/21/2008 11:58 PM, Jiri Slaby wrote: > > >Leaving untouched. > > > > > >On 04/21/2008 11:18 PM, Jiri Slaby wrote: > > >>On 04/21/2008 10:39 PM, David Miller wrote: > > >>>From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > > >>>Date: Mon, 21 Apr 2008 09:54:07 -0700 (PDT) > > >>> > > >>>>What I find interesting is that at least for me, I have the SLAB > > >>>>bucket size for nf_conntrack_expect being 208 bytes. And the > > >>>>*biggest* merge by far after 2.6.25 so far has been networking (and > > >>>>conntrack in particular) > > >>>> > > >>>>Is that a smoking gun? Not necessarily. But it *is* intriguing. But > > >>>>there are other possible clashes (the 192-byte bucket has several > > >>>>different suspects, and not all of them are in networking).1 > > >>> > > >>>I think you might be onto something here. > > >>> > > >>>The "mask" member of struct nf_conntrack_expect could be reasonably > > >>>all 1's like the value reported in the crash that begins this > > >>>thread. > > >>> > > >>>Do we know the offset within the object at which this all 1's > > >>>value is found? > > >>> > > >>>My rough calculations show that on 32-bit that expect->mask member is > > >>>at offset 56 and on 64-bit it should be at offset 72. Does that > > >>>match up to the offset of the filp or whatever bit being corrupted? > > >> > > >>dentry.d_name.name is 56 on 64-bit (my memcmp crashes) > > >>dentry.d_hash.next is 24 (crashed at least 3 times here, rafael's one) > > >>dentry.d_op is 136 (crash below) > > > > > >file.f_mapping is 176 (the another one from -rc8-mm2) > > > > > >the one at: > > >http://www.opensubscriber.com/message/linux-kernel@xxxxxxxxxxxxxxx/9008289.html > > > > > > > > >Having slub_debug enabled, tomorrow will be results, I guess... > > > > Sorry, one more entry: > > > > 00000000000000f0 dentry.d_op (Zdenek, offset ? around 136) > > 00f0000000000000 dentry.d_hash.next (me, offset 24) > > ffff81f02003f16c dentry.d_name.name (me, offset 56) > > memory ORed by 000000f000000000 > > fffff0002004c1b0 file.f_mapping (me, offset 176) > > memory hole, it was something like > > (ffff81002004c1b0 & ~00000f0000000000) | 0000f00000000000? > > ffffffffffffffff dentry.d_hash.next (Rafael, offset ? around 24) > > -1, ~0ULL > > Are these running with CONFIG_PREEMPT_RCU? Grasping at straws, but > there are a couple of patches that need to move from -rt to mainline, > but mostly related to SELinux. So if both PREEMPT_RCU and SELinux > were in use, we might be missing "rcu-various-fixups.patch" from: > > http://www.kernel.org/pub/linux/kernel/projects/rt/patch-2.6.24.4-rt4-broken-out.tar.bz2 My kernel is only voluntarily preemptible (ie. CONFIG_PREEMPT_VOLUNTARY=y). It is an SMP one, however. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
