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authorTejun Heo <tj@kernel.org>2011-03-04 19:09:02 +0100
committerTejun Heo <tj@kernel.org>2011-03-04 19:09:02 +0100
commite83a46bbb1d4c03defd733a64b727632a40059ad (patch)
treec4bc4822b2d3af1bf38095f531adc0a2aac054a5 /arch/x86/kernel/cpu/perf_event_p4.c
parentda527770007fce8e4541947d47918248286da875 (diff)
parentfd51469fb68b987032e46297e0a4fe9020063c20 (diff)
downloadop-kernel-dev-e83a46bbb1d4c03defd733a64b727632a40059ad.zip
op-kernel-dev-e83a46bbb1d4c03defd733a64b727632a40059ad.tar.gz
Merge branch 'for-linus' of ../linux-2.6-block into block-for-2.6.39/core
This merge creates two set of conflicts. One is simple context conflicts caused by removal of throtl_scheduled_delayed_work() in for-linus and removal of throtl_shutdown_timer_wq() in for-2.6.39/core. The other is caused by commit 255bb490c8 (block: blk-flush shouldn't call directly into q->request_fn() __blk_run_queue()) in for-linus crashing with FLUSH reimplementation in for-2.6.39/core. The conflict isn't trivial but the resolution is straight-forward. * __blk_run_queue() calls in flush_end_io() and flush_data_end_io() should be called with @force_kblockd set to %true. * elv_insert() in blk_kick_flush() should use %ELEVATOR_INSERT_REQUEUE. Both changes are to avoid invoking ->request_fn() directly from request completion path and closely match the changes in the commit 255bb490c8. Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event_p4.c')
-rw-r--r--arch/x86/kernel/cpu/perf_event_p4.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index f7a0993..ff751a9 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -770,9 +770,14 @@ static inline int p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc)
return 1;
}
- /* it might be unflagged overflow */
- rdmsrl(hwc->event_base + hwc->idx, v);
- if (!(v & ARCH_P4_CNTRVAL_MASK))
+ /*
+ * In some circumstances the overflow might issue an NMI but did
+ * not set P4_CCCR_OVF bit. Because a counter holds a negative value
+ * we simply check for high bit being set, if it's cleared it means
+ * the counter has reached zero value and continued counting before
+ * real NMI signal was received:
+ */
+ if (!(v & ARCH_P4_UNFLAGGED_BIT))
return 1;
return 0;
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