From patchwork Thu Jul 14 08:34:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 71989 Delivered-To: patch@linaro.org Received: by 10.140.29.52 with SMTP id a49csp1412833qga; Thu, 14 Jul 2016 01:36:55 -0700 (PDT) X-Received: by 10.66.197.195 with SMTP id iw3mr8091049pac.82.1468485415029; Thu, 14 Jul 2016 01:36:55 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id dc8si1758506pad.280.2016.07.14.01.36.54; Thu, 14 Jul 2016 01:36:55 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752025AbcGNIgt (ORCPT + 30 others); Thu, 14 Jul 2016 04:36:49 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:6600 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751883AbcGNIfW (ORCPT ); Thu, 14 Jul 2016 04:35:22 -0400 Received: from 172.24.1.60 (EHLO szxeml428-hub.china.huawei.com) ([172.24.1.60]) by szxrg01-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DNQ19062; Thu, 14 Jul 2016 16:35:08 +0800 (CST) Received: from linux-4hy3.site (10.107.193.248) by szxeml428-hub.china.huawei.com (10.82.67.183) with Microsoft SMTP Server id 14.3.235.1; Thu, 14 Jul 2016 16:34:59 +0800 From: Wang Nan To: CC: , , , Wang Nan , He Kuang , "Arnaldo Carvalho de Melo" , Jiri Olsa , "Masami Hiramatsu" , Namhyung Kim , "Nilay Vaish" Subject: [PATCH v16 10/15] perf tools: Setup backward mmap state machine Date: Thu, 14 Jul 2016 08:34:42 +0000 Message-ID: <1468485287-33422-11-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1468485287-33422-1-git-send-email-wangnan0@huawei.com> References: <1468485287-33422-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090202.57874EBD.01B0, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: e297a4aa013eeee04f519140ad5d2275 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce a bkw_mmap_state state machine to evlist: .________________(forbid)_____________. | V NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY ^ ^ | ^ | | |__(forbid)____/ |___(forbid)___/| | | \_________________(3)_______________/ NOTREADY : Backward ring buffers are not ready RUNNING : Backward ring buffers are recording DATA_PENDING : We are required to collect data from backward ring buffers EMPTY : We have collected data from backward ring buffers. (0): Setup backward ring buffer (1): Pause ring buffers for reading (2): Read from ring buffers (3): Resume ring buffers for recording We can't avoid this complexity. Since we deliberately drop records from overwritable ring buffer, there's no way for us to check remaining from ring buffer itself (by checking head and old pointers). Therefore, we need DATA_PENDING and EMPTY state to help us recording what we have done to the ring buffer. In record__mmap_read_evlist(), drive this state machine from DATA_PENDING to EMPTY. In perf_evlist__mmap_per_evsel(), drive this state machine from NOTREADY to RUNNING when creating backward mmap. Signed-off-by: Wang Nan Cc: He Kuang Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: Nilay Vaish Cc: pi3orama@163.com --- tools/perf/builtin-record.c | 5 ++++ tools/perf/util/evlist.c | 63 +++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/evlist.h | 32 +++++++++++++++++++++++ 3 files changed, 100 insertions(+) -- 1.8.3.4 diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index dbcb223..d4f15e7 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -513,6 +513,9 @@ static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evli if (!maps) return 0; + if (backward && evlist->bkw_mmap_state != BKW_MMAP_DATA_PENDING) + return 0; + for (i = 0; i < evlist->nr_mmaps; i++) { struct auxtrace_mmap *mm = &maps[i].auxtrace_mmap; @@ -538,6 +541,8 @@ static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evli if (bytes_written != rec->bytes_written) rc = record__write(rec, &finished_round_event, sizeof(finished_round_event)); + if (backward) + perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_EMPTY); out: return rc; } diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 5beb44f..400cb22 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -15,6 +15,7 @@ #include "evlist.h" #include "evsel.h" #include "debug.h" +#include "asm/bug.h" #include #include "parse-events.h" @@ -44,6 +45,7 @@ void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus, perf_evlist__set_maps(evlist, cpus, threads); fdarray__init(&evlist->pollfd, 64); evlist->workload.pid = -1; + evlist->bkw_mmap_state = BKW_MMAP_NOTREADY; } struct perf_evlist *perf_evlist__new(void) @@ -1068,6 +1070,8 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx, if (!maps) return -1; evlist->backward_mmap = maps; + if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY) + perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING); } } @@ -1972,3 +1976,62 @@ perf_evlist__find_evsel_by_str(struct perf_evlist *evlist, return NULL; } + +void +perf_evlist__toggle_bkw_mmap(struct perf_evlist *evlist, + enum bkw_mmap_state state) +{ + enum bkw_mmap_state old_state = evlist->bkw_mmap_state; + enum action { + NONE, + PAUSE, + RESUME, + } action = NONE; + + if (!evlist->backward_mmap) + return; + + switch (old_state) { + case BKW_MMAP_NOTREADY: { + if (state != BKW_MMAP_RUNNING) + goto state_err;; + break; + } + case BKW_MMAP_RUNNING: { + if (state != BKW_MMAP_DATA_PENDING) + goto state_err; + action = PAUSE; + break; + } + case BKW_MMAP_DATA_PENDING: { + if (state != BKW_MMAP_EMPTY) + goto state_err; + break; + } + case BKW_MMAP_EMPTY: { + if (state != BKW_MMAP_RUNNING) + goto state_err; + action = RESUME; + break; + } + default: + WARN_ONCE(1, "Shouldn't get there\n"); + } + + evlist->bkw_mmap_state = state; + + switch (action) { + case PAUSE: + perf_evlist__pause(evlist); + break; + case RESUME: + perf_evlist__resume(evlist); + break; + case NONE: + default: + break; + } + +state_err: + return; +} diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 6a3d9bd..a2b84dd 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -41,6 +41,34 @@ perf_mmap__mmap_len(struct perf_mmap *map) return map->mask + 1 + page_size; } +/* + * State machine of bkw_mmap_state: + * + * .________________(forbid)_____________. + * | V + * NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY + * ^ ^ | ^ | + * | |__(forbid)____/ |___(forbid)___/| + * | | + * \_________________(3)_______________/ + * + * NOTREADY : Backward ring buffers are not ready + * RUNNING : Backward ring buffers are recording + * DATA_PENDING : We are required to collect data from backward ring buffers + * EMPTY : We have collected data from backward ring buffers. + * + * (0): Setup backward ring buffer + * (1): Pause ring buffers for reading + * (2): Read from ring buffers + * (3): Resume ring buffers for recording + */ +enum bkw_mmap_state { + BKW_MMAP_NOTREADY, + BKW_MMAP_RUNNING, + BKW_MMAP_DATA_PENDING, + BKW_MMAP_EMPTY, +}; + struct perf_evlist { struct list_head entries; struct hlist_head heads[PERF_EVLIST__HLIST_SIZE]; @@ -54,6 +82,7 @@ struct perf_evlist { int id_pos; int is_pos; u64 combined_sample_type; + enum bkw_mmap_state bkw_mmap_state; struct { int cork_fd; pid_t pid; @@ -135,6 +164,9 @@ struct perf_evsel *perf_evlist__id2evsel_strict(struct perf_evlist *evlist, struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id); +void +perf_evlist__toggle_bkw_mmap(struct perf_evlist *evlist, enum bkw_mmap_state state); + union perf_event *perf_mmap__read_forward(struct perf_mmap *map, bool check_messup); union perf_event *perf_mmap__read_backward(struct perf_mmap *map);