diff options
author | Stephane Eranian <eranian@google.com> | 2014-09-24 11:48:37 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2014-11-16 10:41:57 (GMT) |
commit | 60e2364e60e86e81bc6377f49779779e6120977f (patch) | |
tree | 669f675c67744cbdd61291f2ec3d03cbb51288d3 /kernel/events | |
parent | af4bdcf675cf768dc3558682fc178e0e3e70bb52 (diff) | |
download | linux-60e2364e60e86e81bc6377f49779779e6120977f.tar.xz |
perf: Add ability to sample machine state on interrupt
Enable capture of interrupted machine state for each sample.
Registers to sample are passed per event in the sample_regs_intr bitmask.
To sample interrupt machine state, the PERF_SAMPLE_INTR_REGS must be passed in
sample_type.
The list of available registers is arch dependent and provided by asm/perf_regs.h
Registers are laid out as u64 in the order of the bit order of sample_intr_regs.
This patch also adds a new ABI version PERF_ATTR_SIZE_VER4 because we extend
the perf_event_attr struct with a new u64 field.
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: cebbert.lkml@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/1411559322-16548-2-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
-rw-r--r-- | kernel/events/core.c | 46 |
1 files changed, 44 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 1cd5eef..c2be159 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4460,7 +4460,7 @@ perf_output_sample_regs(struct perf_output_handle *handle, } } -static void perf_sample_regs_user(struct perf_regs_user *regs_user, +static void perf_sample_regs_user(struct perf_regs *regs_user, struct pt_regs *regs) { if (!user_mode(regs)) { @@ -4476,6 +4476,14 @@ static void perf_sample_regs_user(struct perf_regs_user *regs_user, } } +static void perf_sample_regs_intr(struct perf_regs *regs_intr, + struct pt_regs *regs) +{ + regs_intr->regs = regs; + regs_intr->abi = perf_reg_abi(current); +} + + /* * Get remaining task size from user stack pointer. * @@ -4857,6 +4865,23 @@ void perf_output_sample(struct perf_output_handle *handle, if (sample_type & PERF_SAMPLE_TRANSACTION) perf_output_put(handle, data->txn); + if (sample_type & PERF_SAMPLE_REGS_INTR) { + u64 abi = data->regs_intr.abi; + /* + * If there are no regs to dump, notice it through + * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). + */ + perf_output_put(handle, abi); + + if (abi) { + u64 mask = event->attr.sample_regs_intr; + + perf_output_sample_regs(handle, + data->regs_intr.regs, + mask); + } + } + if (!event->attr.watermark) { int wakeup_events = event->attr.wakeup_events; @@ -4943,7 +4968,7 @@ void perf_prepare_sample(struct perf_event_header *header, * in case new sample type is added, because we could eat * up the rest of the sample size. */ - struct perf_regs_user *uregs = &data->regs_user; + struct perf_regs *uregs = &data->regs_user; u16 stack_size = event->attr.sample_stack_user; u16 size = sizeof(u64); @@ -4964,6 +4989,21 @@ void perf_prepare_sample(struct perf_event_header *header, data->stack_user_size = stack_size; header->size += size; } + + if (sample_type & PERF_SAMPLE_REGS_INTR) { + /* regs dump ABI info */ + int size = sizeof(u64); + + perf_sample_regs_intr(&data->regs_intr, regs); + + if (data->regs_intr.regs) { + u64 mask = event->attr.sample_regs_intr; + + size += hweight64(mask) * sizeof(u64); + } + + header->size += size; + } } static void perf_event_output(struct perf_event *event, @@ -7151,6 +7191,8 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr, ret = -EINVAL; } + if (attr->sample_type & PERF_SAMPLE_REGS_INTR) + ret = perf_reg_validate(attr->sample_regs_intr); out: return ret; |