linux/arch/x86/events/intel
Peter Zijlstra efe951d3de perf/x86: Fix perf,x86,cpuhp deadlock
More lockdep gifts, a 5-way lockup race:

	perf_event_create_kernel_counter()
	  perf_event_alloc()
	    perf_try_init_event()
	      x86_pmu_event_init()
		__x86_pmu_event_init()
		  x86_reserve_hardware()
 #0		    mutex_lock(&pmc_reserve_mutex);
		    reserve_ds_buffer()
 #1		      get_online_cpus()

	perf_event_release_kernel()
	  _free_event()
	    hw_perf_event_destroy()
	      x86_release_hardware()
 #0		mutex_lock(&pmc_reserve_mutex)
		release_ds_buffer()
 #1		  get_online_cpus()

 #1	do_cpu_up()
	  perf_event_init_cpu()
 #2	    mutex_lock(&pmus_lock)
 #3	    mutex_lock(&ctx->mutex)

	sys_perf_event_open()
	  mutex_lock_double()
 #3	    mutex_lock(ctx->mutex)
 #4	    mutex_lock_nested(ctx->mutex, 1);

	perf_try_init_event()
 #4	  mutex_lock_nested(ctx->mutex, 1)
	  x86_pmu_event_init()
	    intel_pmu_hw_config()
	      x86_add_exclusive()
 #0		mutex_lock(&pmc_reserve_mutex)

Fix it by using ordering constructs instead of locking.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-25 14:48:30 +01:00
..
bts.c x86,perf: Disable intel_bts when PTI 2018-01-14 11:42:10 +01:00
core.c perf/x86/intel: Plug memory leak in intel_pmu_init() 2017-12-27 20:23:59 +01:00
cstate.c perf/x86/intel/cstate: Add missing CPU IDs 2017-09-25 09:36:17 +02:00
ds.c perf/x86: Fix perf,x86,cpuhp deadlock 2018-01-25 14:48:30 +01:00
knc.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
lbr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
p4.c x86: Mark various structures and functions as 'static' 2017-08-11 14:49:43 +02:00
p6.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pt.c perf/core, pt, bts: Get rid of itrace_started 2017-08-29 15:09:24 +02:00
pt.h perf/x86/intel/pt: Allow the disabling of branch tracing 2017-03-30 09:53:49 +02:00
rapl.c perf/x86/rapl: Fix Haswell and Broadwell server RAPL event 2018-01-12 14:59:54 +01:00
uncore_nhmex.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
uncore_snb.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
uncore_snbep.c Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:11:54 -08:00
uncore.c perf/x86/intel/uncore: Cache logical pkg id in uncore driver 2017-11-17 16:22:30 +01:00
uncore.h perf/x86/intel/uncore: Cache logical pkg id in uncore driver 2017-11-17 16:22:30 +01:00