From ea5d20cf99db5d26d43b6d322d3ace17e08a6552 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 25 Mar 2009 12:30:25 +0100 Subject: [PATCH] perf_counter: optionally provide the pid/tid of the sampled task Allow cpu wide counters to profile userspace by providing what process the sample belongs to. This raises the first issue with the output type, lots of these options: group, tid, callchain, etc.. are non-exclusive and could be combined, suggesting a bitfield. However, things like the mmap() data stream doesn't fit in that. How to split the type field... Signed-off-by: Peter Zijlstra Cc: Paul Mackerras Cc: Mike Galbraith Cc: Arjan van de Ven Cc: Wu Fengguang Orig-LKML-Reference: <20090325113317.013775235@chello.nl> Signed-off-by: Ingo Molnar --- include/linux/perf_counter.h | 5 ++++- kernel/perf_counter.c | 18 ++++++++++++++++-- 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index c256635377d4..7fdbdf8be775 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -127,8 +127,9 @@ struct perf_counter_hw_event { exclude_kernel : 1, /* ditto kernel */ exclude_hv : 1, /* ditto hypervisor */ exclude_idle : 1, /* don't count when idle */ + include_tid : 1, /* include the tid */ - __reserved_1 : 55; + __reserved_1 : 54; __u32 extra_config_len; __u32 __reserved_4; @@ -164,6 +165,8 @@ struct perf_event_header { enum perf_event_type { PERF_EVENT_IP = 0, PERF_EVENT_GROUP = 1, + + __PERF_EVENT_TID = 0x100, }; #ifdef __KERNEL__ diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 7669afe82cc7..f3e1b27bc1b8 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1528,16 +1528,30 @@ static int perf_output_write(struct perf_counter *counter, int nmi, static void perf_output_simple(struct perf_counter *counter, int nmi, struct pt_regs *regs) { + unsigned int size; struct { struct perf_event_header header; u64 ip; + u32 pid, tid; } event; event.header.type = PERF_EVENT_IP; - event.header.size = sizeof(event); event.ip = instruction_pointer(regs); - perf_output_write(counter, nmi, &event, sizeof(event)); + size = sizeof(event); + + if (counter->hw_event.include_tid) { + /* namespace issues */ + event.pid = current->group_leader->pid; + event.tid = current->pid; + + event.header.type |= __PERF_EVENT_TID; + } else + size -= sizeof(u64); + + event.header.size = size; + + perf_output_write(counter, nmi, &event, size); } static void perf_output_group(struct perf_counter *counter, int nmi) -- GitLab