We currently bundle the callchain handling code with the PMU code,
despite the fact the two are distinct, and the former can be useful even
in the absence of the latter.
Follow the example of arch/arm and factor the callchain handling into
its own file dependent on CONFIG_PERF_EVENTS rather than
CONFIG_HW_PERF_EVENTS.
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>
For ARM64, when tracing with tracepoint events, the IP and pstate are set
to 0, preventing the perf code parsing the callchain and resolving the
symbols correctly.
./perf record -e sched:sched_switch -g --call-graph dwarf ls
[ perf record: Captured and wrote 0.146 MB perf.data ]
./perf report -f
Samples: 194 of event 'sched:sched_switch', Event count (approx.): 194
Children Self Command Shared Object Symbol
100.00% 100.00% ls [unknown] [.] 0000000000000000
The fix is to implement perf_arch_fetch_caller_regs for ARM64, which fills
several necessary registers used for callchain unwinding, including pc,sp,
fp and spsr .
With this patch, callchain can be parsed correctly as follows:
......
+ 2.63% 0.00% ls [kernel.kallsyms] [k] vfs_symlink
+ 2.63% 0.00% ls [kernel.kallsyms] [k] follow_down
+ 2.63% 0.00% ls [kernel.kallsyms] [k] pfkey_get
+ 2.63% 0.00% ls [kernel.kallsyms] [k] do_execveat_common.isra.33
- 2.63% 0.00% ls [kernel.kallsyms] [k] pfkey_send_policy_notify
pfkey_send_policy_notify
pfkey_get
v9fs_vfs_rename
page_follow_link_light
link_path_walk
el0_svc_naked
.......
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add minimal guest support to perf, so it can distinguish whether
the PMU interrupt was in the host or the guest, as well as collecting
some very basic information (guest PC, user vs kernel mode).
This is not feature complete though, as it doesn't support backtracing
in the guest.
Based on the x86 implementation, tested with KVM/arm64.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch adds support for the AArch64 performance counters.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Mark Rutland