Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx> writes: > On 2011.12.18 at 19:21 -0800, Eric W. Biederman wrote: >> Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx> writes: >> >> > On 2011.11.21 at 17:34 +0100, Markus Trippelsdorf wrote: >> >> On 2011.11.21 at 17:10 +0100, Markus Trippelsdorf wrote: >> >> > On 2011.11.21 at 16:48 +0100, Eric Dumazet wrote: >> >> > > Le lundi 21 novembre 2011 à 16:36 +0100, Markus Trippelsdorf a écrit : >> >> > > > On 2011.11.21 at 15:16 +0100, Eric Dumazet wrote: >> >> > > > > Le lundi 21 novembre 2011 à 14:15 +0100, Markus Trippelsdorf a écrit : >> >> > > > > >> >> > > > > > I've enabled CONFIG_SLUB_DEBUG_ON and this is what happend: >> >> > > > > > >> >> > > > > >> >> > > > > Thanks >> >> > > > > >> >> > > > > Please continue to provide more samples. >> >> > > > > >> >> > > > > There is something wrong somewhere, but where exactly, its hard to say. >> >> > > > >> >> > > > New sample. This one points to lib/idr.c: >> >> > > > >> >> > > > ============================================================================= >> >> > > > BUG idr_layer_cache: Poison overwritten >> >> > > > ----------------------------------------------------------------------------- >> >> > > >> >> > > Thanks, could you now add "CONFIG_DEBUG_PAGEALLOC=y" in your config as >> >> > > well ? >> >> > >> >> > Sure. This one happend with CONFIG_DEBUG_PAGEALLOC=y: >> >> > >> >> > ============================================================================= >> >> > BUG task_struct: Poison overwritten >> >> > ----------------------------------------------------------------------------- >> >> >> >> And sometimes this one that I've reported earlier already: >> >> >> >> (see: http://thread.gmane.org/gmane.linux.kernel/1215023 ) >> >> >> >> ------------[ cut here ]------------ >> >> WARNING: at fs/sysfs/sysfs.h:195 sysfs_get_inode+0x136/0x140() >> >> Hardware name: System Product Name >> >> Pid: 1876, comm: slabinfo Not tainted 3.2.0-rc2-00274-g6fe4c6d #72 >> >> Call Trace: >> >> [<ffffffff8106cac5>] warn_slowpath_common+0x75/0xb0 >> >> [<ffffffff8106cbc5>] warn_slowpath_null+0x15/0x20 >> >> [<ffffffff81163236>] sysfs_get_inode+0x136/0x140 >> >> [<ffffffff81164cef>] sysfs_lookup+0x6f/0x110 >> >> [<ffffffff811173f9>] d_alloc_and_lookup+0x39/0x80 >> >> [<ffffffff81118774>] do_lookup+0x294/0x3a0 >> >> [<ffffffff8111798a>] ? inode_permission+0x7a/0xb0 >> >> [<ffffffff8111a3f7>] do_last.isra.46+0x137/0x7f0 >> >> [<ffffffff8111ab76>] path_openat+0xc6/0x370 >> >> [<ffffffff81117606>] ? getname_flags+0x36/0x230 >> >> [<ffffffff810ec852>] ? handle_mm_fault+0x192/0x290 >> >> [<ffffffff8111ae5c>] do_filp_open+0x3c/0x90 >> >> [<ffffffff81127c8c>] ? alloc_fd+0xdc/0x120 >> >> [<ffffffff8110ce77>] do_sys_open+0xe7/0x1c0 >> >> [<ffffffff8110cf6b>] sys_open+0x1b/0x20 >> >> [<ffffffff814ccb7b>] system_call_fastpath+0x16/0x1b >> >> ---[ end trace b1377eb8b131d37d ]--- >> > >> > Hm, the "sysfs: use rb-tree" thing hit again during boot. Could this be >> > the root cause of this all? >> > >> > I wrote down the following: >> > >> > RIP : rb_next >> > >> > Trace: >> > sysfs_dir_pos >> > sysfs_readdir >> > ? sys_ioctl >> > vfs_readdir >> > sys_getdents >> >> Thanks for reporting this. >> >> Has this by any chance been resolved or stopped happening? > > Yes. > >> This looks for all of the world like something is stomping your sysfs >> dirents. I haven't seen anyone else complaining so this seems like the >> problem is unique to your configuration. Which suggests that it is not >> sysfs itself that is wrong. >> >> I have been through the code a time or two and I haven't seen anything >> obviously wrong. Everything that sysfs does is protected by the >> sysfs_mutex so the locking is very very simple. >> >> My best guess of why now is that the rbtree code make a sysfs dirent >> 48 bytes larger. And so it is much more exposed to these kinds of >> problems. > > Sorry, but your subsystem was just accidentally hit by a bug in the > Radeon driver, that sometimes randomly writes 0 dwords somewhere to > memory after a kexec boot (see the rest of this huge thread). > It's still not fixed in mainline, because Linus refused to take the fix > this late in the series. Awesome. I guess that means I am only responsible for the Radeon driver having the opportunity to take that code path. It is nice to see kexec being used and being well known enough I didn't have to get involved. Eric -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href