David Ahern c17af4dd96 sparc: perf: Disable pagefaults while walking userspace stacks ... Page faults generated walking userspace stacks can call schedule to switch out the task. When collecting callchains for scheduler tracepoints this causes a deadlock as the tracepoints can be hit with the runqueue lock held: [ 8138.159054] WARNING: CPU: 758 PID: 12488 at /opt/dahern/linux.git/arch/sparc/kernel/nmi.c:80 perfctr_irq+0x1f8/0x2b4() [ 8138.203152] Watchdog detected hard LOCKUP on cpu 758 [ 8138.410969] CPU: 758 PID: 12488 Comm: perf Not tainted 4.0.0-rc6+ #6 [ 8138.437146] Call Trace: [ 8138.447193] [000000000045cdd4] warn_slowpath_common+0x7c/0xa0 [ 8138.471238] [000000000045ce90] warn_slowpath_fmt+0x30/0x40 [ 8138.494189] [0000000000983e38] perfctr_irq+0x1f8/0x2b4 [ 8138.515716] [00000000004209f4] tl0_irq15+0x14/0x20 [ 8138.535791] [00000000009839ec] _raw_spin_trylock_bh+0x68/0x108 [ 8138.560180] [0000000000980018] __schedule+0xcc/0x710 [ 8138.580981] [00000000009806dc] preempt_schedule_common+0x10/0x3c [ 8138.606082] [000000000098077c] _cond_resched+0x34/0x44 [ 8138.627603] [0000000000565990] kmem_cache_alloc_node+0x24/0x1a0 [ 8138.652345] [0000000000450b60] tsb_grow+0xac/0x488 [ 8138.672429] [0000000000985040] do_sparc64_fault+0x4dc/0x6e4 [ 8138.695736] [0000000000407c2c] sparc64_realfault_common+0x10/0x20 [ 8138.721202] [00000000006f2e24] NG4copy_from_user+0xa4/0x3c0 [ 8138.744510] [000000000044f900] perf_callchain_user+0x5c/0x6c [ 8138.768182] [0000000000517b5c] perf_callchain+0x16c/0x19c [ 8138.790774] [0000000000515f84] perf_prepare_sample+0x68/0x218 [ 8138.814801] ---[ end trace 42ca6294b1ff7573 ]--- As with PowerPC (b59a1bfcc2, "powerpc/perf: Disable pagefaults during callchain stack read") disable pagefaults while walking userspace stacks. Signed-off-by: David Ahern <david.ahern@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2015-06-25 06:01:02 -07:00
..
boot	sparc: Add "install" target	2014-08-04 20:45:59 -07:00
configs	sparc: Set CONFIG_NET=y in defconfigs	2014-09-24 13:38:30 -04:00
crypto	crypto: sparc/md5 - use md5 IV MD5_HX instead of their raw value	2015-05-18 12:20:20 +08:00
include	mm: clarify that the function operates on hugepage pte	2015-06-24 17:49:44 -07:00
kernel	sparc: perf: Disable pagefaults while walking userspace stacks	2015-06-25 06:01:02 -07:00
lib	sparc64: Fix several bugs in memmove().	2015-03-23 09:22:10 -07:00
math-emu	arch/sparc/math-emu/math_32.c: drop stray break operator	2014-08-04 20:29:06 -07:00
mm	mm/memblock: add extra "flags" to memblock to allow selection of memory based on attribute	2015-06-24 17:49:44 -07:00
net	module: remove mod arg from module_free, rename module_memfree().	2015-01-20 11:38:33 +10:30
oprofile
power	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc	2014-10-11 20:36:34 -04:00
prom	sparc64: Fix register corruption in top-most kernel stack frame during boot.	2014-10-24 09:52:49 -07:00
Kbuild	sparc64: Add SHA1 driver making use of the 'sha1' instruction.	2012-08-20 15:08:49 -07:00
Kconfig	sparc: expose number of page table levels	2015-04-14 16:49:02 -07:00
Kconfig.debug	lib: consolidate DEBUG_STACK_USAGE option	2011-05-25 08:39:54 -07:00
Makefile	sparc: Add "install" target	2014-08-04 20:45:59 -07:00