OpenCloudOS-Kernel/include
Mark Rutland 48538b5863 drivers/perf: arm_pmu: expose a cpumask in sysfs
In systems with heterogeneous CPUs, there are multiple logical CPU PMUs,
each of which covers a subset of CPUs in the system. In some cases
userspace needs to know which CPUs a given logical PMU covers, so we'd
like to expose a cpumask under sysfs, similar to what is done for uncore
PMUs.

Unfortunately, prior to commit 00e727bb38 ("perf stat: Balance
opening and reading events"), perf stat only correctly handled a cpumask
holding a single CPU, and only when profiling in system-wide mode. In
other cases, the presence of a cpumask file could cause perf stat to
behave erratically.

Thus, exposing a cpumask file would break older perf binaries in cases
where they would otherwise work.

To avoid this issue while still providing userspace with the information
it needs, this patch exposes a differently-named file (cpus) under
sysfs. New tools can look for this and operate correctly, while older
tools will not be adversely affected by its presence.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09 14:51:51 +01:00
..
acpi treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
asm-generic locking/qrwlock: Fix write unlock bug on big endian systems 2016-08-10 14:13:27 +02:00
clocksource clocksource/drivers/sp804: Convert init function to return error 2016-06-28 10:19:30 +02:00
crypto A number of improvements for the /dev/random driver; the most 2016-07-27 15:11:55 -07:00
drm Merge branch 'drm-next-4.8' of git://people.freedesktop.org/~agd5f/linux into drm-next 2016-08-08 16:45:33 +10:00
dt-bindings ARM: DT updates for v4.8 2016-08-01 18:37:45 -04:00
keys KEYS: Strip trailing spaces 2016-06-14 10:29:44 +01:00
kvm KVM/ARM Changes for v4.8 - Take 2 2016-08-04 13:59:56 +02:00
linux drivers/perf: arm_pmu: expose a cpumask in sysfs 2016-09-09 14:51:51 +01:00
math-emu
media dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
memory
misc cxl: Add cxl_check_and_switch_mode() API to switch bi-modal cards 2016-07-14 20:28:11 +10:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-08-17 17:26:58 -07:00
pcmcia
ras tracing, RAS: Cleanup on __get_str() usage 2016-07-15 15:51:16 -04:00
rdma Second round of merge items for 4.8 2016-08-04 20:26:31 -04:00
rxrpc
scsi Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-08-04 20:04:37 -04:00
soc ARM: SoC driver updates for v4.8 2016-08-01 18:36:01 -04:00
sound Merge tag 'drm-for-v4.8' of git://people.freedesktop.org/~airlied/linux 2016-08-01 21:44:08 -04:00
target target: Fix ordered task CHECK_CONDITION early exception handling 2016-07-20 00:58:40 -07:00
trace Luiz Capitulino noticed that the tick_stop tracepoint wasn't being parsed 2016-08-09 10:34:09 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-08-17 17:26:58 -07:00
video gpu: ipu-v3: ipu-dmfc: Use static DMFC FIFO allocation mechanism 2016-07-12 18:23:43 +02:00
xen dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
Kbuild