Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754930AbaGHWQt (ORCPT ); Tue, 8 Jul 2014 18:16:49 -0400 Received: from mail-wi0-f177.google.com ([209.85.212.177]:50032 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754590AbaGHWQp (ORCPT ); Tue, 8 Jul 2014 18:16:45 -0400 From: Stephane Eranian To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, mingo@elte.hu, ak@linux.intel.com, jolsa@redhat.com, acme@redhat.com, namhyung@kernel.org Subject: [PATCH 1/4] perf: add ability to sample machine state on interrupt Date: Wed, 9 Jul 2014 00:15:56 +0200 Message-Id: <1404857759-25105-2-git-send-email-eranian@google.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1404857759-25105-1-git-send-email-eranian@google.com> References: <1404857759-25105-1-git-send-email-eranian@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Enable capture of interrupted machine state in 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. Signed-off-by: Stephane Eranian --- include/linux/perf_event.h | 7 +++++-- include/uapi/linux/perf_event.h | 14 ++++++++++++- kernel/events/core.c | 44 +++++++++++++++++++++++++++++++++++++++-- 3 files changed, 60 insertions(+), 5 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 707617a..4970c1d 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -78,7 +78,7 @@ struct perf_branch_stack { struct perf_branch_entry entries[0]; }; -struct perf_regs_user { +struct perf_regs { __u64 abi; struct pt_regs *regs; }; @@ -595,7 +595,8 @@ struct perf_sample_data { struct perf_callchain_entry *callchain; struct perf_raw_record *raw; struct perf_branch_stack *br_stack; - struct perf_regs_user regs_user; + struct perf_regs regs_user; + struct perf_regs regs_intr; u64 stack_user_size; u64 weight; /* @@ -618,6 +619,8 @@ static inline void perf_sample_data_init(struct perf_sample_data *data, data->weight = 0; data->data_src.val = 0; data->txn = 0; + data->regs_intr.abi = PERF_SAMPLE_REGS_ABI_NONE; + data->regs_intr.regs = NULL; } extern void perf_output_sample(struct perf_output_handle *handle, diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 9269de2..543cc19 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -137,8 +137,9 @@ enum perf_event_sample_format { PERF_SAMPLE_DATA_SRC = 1U << 15, PERF_SAMPLE_IDENTIFIER = 1U << 16, PERF_SAMPLE_TRANSACTION = 1U << 17, + PERF_SAMPLE_REGS_INTR = 1U << 18, - PERF_SAMPLE_MAX = 1U << 18, /* non-ABI */ + PERF_SAMPLE_MAX = 1U << 19, /* non-ABI */ }; /* @@ -334,6 +335,15 @@ struct perf_event_attr { /* Align to u64. */ __u32 __reserved_2; + /* + * Defines set of user regs to dump on samples. + * state capture on: + * - precise = 0: PMU interrupt + * - precise > 0: sampled instruction + * + * See asm/perf_regs.h for details. + */ + __u64 sample_regs_intr; }; #define perf_flags(attr) (*(&(attr)->read_format + 1)) @@ -686,6 +696,8 @@ enum perf_event_type { * { u64 weight; } && PERF_SAMPLE_WEIGHT * { u64 data_src; } && PERF_SAMPLE_DATA_SRC * { u64 transaction; } && PERF_SAMPLE_TRANSACTION + * { u64 abi; # enum perf_sample_regs_abi + * u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_INTR * }; */ PERF_RECORD_SAMPLE = 9, diff --git a/kernel/events/core.c b/kernel/events/core.c index 57e9190..018939c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4296,7 +4296,7 @@ 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)) { @@ -4312,6 +4312,14 @@ static void perf_sample_regs_user(struct perf_regs_user *regs_user, } } +static void perf_sample_regs_intr(struct perf_regs *regs_user, + struct pt_regs *regs) +{ + regs_user->regs = regs; + regs_user->abi = perf_reg_abi(current); +} + + /* * Get remaining task size from user stack pointer. * @@ -4693,6 +4701,22 @@ 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; @@ -4779,7 +4803,7 @@ 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); @@ -4800,6 +4824,20 @@ 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, @@ -6994,6 +7032,8 @@ 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; -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/