From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760636AbZENLsz (ORCPT ); Thu, 14 May 2009 07:48:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758858AbZENLsg (ORCPT ); Thu, 14 May 2009 07:48:36 -0400 Received: from bilbo.ozlabs.org ([203.10.76.25]:40191 "EHLO bilbo.ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759531AbZENLsf (ORCPT ); Thu, 14 May 2009 07:48:35 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18956.1272.818511.561835@cargo.ozlabs.ibm.com> Date: Thu, 14 May 2009 21:48:08 +1000 From: Paul Mackerras To: Ingo Molnar CC: Peter Zijlstra , linux-kernel@vger.kernel.org, Corey Ashford , Thomas Gleixner Subject: [PATCH 2/3 v2] perf_counter: allow arch to supply event misc flags and instruction pointer X-Mailer: VM 8.0.12 under 22.2.1 (i486-pc-linux-gnu) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At present the values we put in overflow events for the misc flags indicating processor mode and the instruction pointer are obtained using the standard user_mode() and instruction_pointer() functions. Those functions tell you where the performance monitor interrupt was taken, which might not be exactly where the counter overflow occurred, for example because interrupts were disabled at the point where the overflow occurred, or because the processor had many instructions in flight and chose to complete some more instructions beyond the one that caused the counter overflow. Some architectures (e.g. powerpc) can supply more precise information about where the counter overflow occurred and the processor mode at that point. This introduces new functions, perf_misc_flags() and perf_instruction_pointer(), which arch code can override to provide more precise information if available. They have default implementations which are identical to the existing code. This also adds a new misc flag value, PERF_EVENT_MISC_HYPERVISOR, for the case where a counter overflow occurred in the hypervisor. We encode the processor mode in the 2 bits previously used to indicate user or kernel mode; the values for user and kernel mode are unchanged and hypervisor mode is indicated by both bits being set. Signed-off-by: Paul Mackerras --- Patches 1/3 and 3/3 of this series are unchanged. Ingo, do you need me to repost them? include/linux/perf_counter.h | 11 ++++++++++- kernel/perf_counter.c | 5 ++--- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 614f921..8ddde14 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -210,8 +210,11 @@ struct perf_counter_mmap_page { __u32 data_head; /* head in the data section */ }; +#define PERF_EVENT_MISC_CPUMODE_MASK (3 << 0) +#define PERF_EVENT_MISC_CPUMODE_UNKNOWN (0 << 0) #define PERF_EVENT_MISC_KERNEL (1 << 0) -#define PERF_EVENT_MISC_USER (1 << 1) +#define PERF_EVENT_MISC_USER (2 << 0) +#define PERF_EVENT_MISC_HYPERVISOR (3 << 0) #define PERF_EVENT_MISC_OVERFLOW (1 << 2) struct perf_event_header { @@ -588,6 +591,12 @@ extern int sysctl_perf_counter_mlock; extern void perf_counter_init(void); +#ifndef perf_misc_flags +#define perf_misc_flags(regs) (user_mode(regs) ? PERF_EVENT_MISC_USER : \ + PERF_EVENT_MISC_KERNEL) +#define perf_instruction_pointer(regs) instruction_pointer(regs) +#endif + #else static inline void perf_counter_task_sched_in(struct task_struct *task, int cpu) { } diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index ff166c1..89568de 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1978,11 +1978,10 @@ static void perf_counter_output(struct perf_counter *counter, header.size = sizeof(header); header.misc = PERF_EVENT_MISC_OVERFLOW; - header.misc |= user_mode(regs) ? - PERF_EVENT_MISC_USER : PERF_EVENT_MISC_KERNEL; + header.misc |= perf_misc_flags(regs); if (record_type & PERF_RECORD_IP) { - ip = instruction_pointer(regs); + ip = perf_instruction_pointer(regs); header.type |= PERF_RECORD_IP; header.size += sizeof(ip); }