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[209.132.180.67]) by mx.google.com with ESMTP id j5-v6si7777730plk.145.2018.10.25.07.42.05; Thu, 25 Oct 2018 07:42:25 -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; dkim=pass header.i=@kernel.org header.s=default header.b=tcGXgpld; 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; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728998AbeJYWsb (ORCPT + 99 others); Thu, 25 Oct 2018 18:48:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:57160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728313AbeJYWsa (ORCPT ); Thu, 25 Oct 2018 18:48:30 -0400 Received: from sasha-vm.mshome.net (unknown [167.98.65.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 69CB32085A; Thu, 25 Oct 2018 14:15:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540476933; bh=F5VXkm2S6J+KqUvZ+j79NIwd2E/NaRDjOabMdhk1yDo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tcGXgpldDlEt+ltLocHjA/lircLRUcYLJdVle4jjvKgIkEoxPG6+7kMdb5X0nlS2y h1d8zjYRJESev/JzGCLs2EjrlXOXA5nVxNwT/Dg3WcFZfw+KY/yUA9e3A+RfG2s2ZM n2w5bYdsrO1zSY0ARieJQe3mnNxynoEerVI9oN4A= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Arnaldo Carvalho de Melo , Adrian Hunter , Alexander Shishkin , David Ahern , Namhyung Kim , Peter Zijlstra , Wang Nan , Sasha Levin Subject: [PATCH AUTOSEL 4.9 46/98] perf evsel: Fix probing of precise_ip level for default cycles event Date: Thu, 25 Oct 2018 10:13:31 -0400 Message-Id: <20181025141423.213774-46-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181025141423.213774-1-sashal@kernel.org> References: <20181025141423.213774-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo [ Upstream commit 7a1ac110c22eb726684c837544a2d42c33e07be7 ] Since commit 18e7a45af91a ("perf/x86: Reject non sampling events with precise_ip") returns -EINVAL for sys_perf_event_open() with an attribute with (attr.precise_ip > 0 && attr.sample_period == 0), just like is done in the routine used to probe the max precise level when no events were passed to 'perf record' or 'perf top', i.e.: perf_evsel__new_cycles() perf_event_attr__set_max_precise_ip() The x86 code, in x86_pmu_hw_config(), which is called all the way from sys_perf_event_open() did, starting with the aforementioned commit: /* There's no sense in having PEBS for non sampling events: */ if (!is_sampling_event(event)) return -EINVAL; Which makes it fail for cycles:ppp, cycles:pp and cycles:p, always using just the non precise cycles variant. To make sure that this is the case, I tested it, before this patch, with: # perf probe -L x86_pmu_hw_config 0 int x86_pmu_hw_config(struct perf_event *event) 1 { 2 if (event->attr.precise_ip) { 17 if (event->attr.precise_ip > precise) 18 return -EOPNOTSUPP; /* There's no sense in having PEBS for non sampling events: */ 21 if (!is_sampling_event(event)) 22 return -EINVAL; } # perf probe x86_pmu_hw_config:22 Added new events: probe:x86_pmu_hw_config (on x86_pmu_hw_config:22) probe:x86_pmu_hw_config_1 (on x86_pmu_hw_config:22) You can now use it in all perf tools, such as: perf record -e probe:x86_pmu_hw_config_1 -aR sleep 1 # perf trace -e perf_event_open,probe:x86_pmu_hwconfig*/max-stack=16/ perf record usleep 1 0.000 ( 0.015 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1 ) ... 0.015 ( ): probe:x86_pmu_hw_config:(ffffffff9c0065e1)) x86_pmu_hw_config ([kernel.kallsyms]) hsw_hw_config ([kernel.kallsyms]) x86_pmu_event_init ([kernel.kallsyms]) perf_try_init_event ([kernel.kallsyms]) perf_event_alloc ([kernel.kallsyms]) SYSC_perf_event_open ([kernel.kallsyms]) sys_perf_event_open ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) return_from_SYSCALL_64 ([kernel.kallsyms]) syscall (/usr/lib64/libc-2.24.so) perf_event_attr__set_max_precise_ip (/home/acme/bin/perf) perf_evsel__new_cycles (/home/acme/bin/perf) perf_evlist__add_default (/home/acme/bin/perf) cmd_record (/home/acme/bin/perf) run_builtin (/home/acme/bin/perf) handle_internal_command (/home/acme/bin/perf) 0.000 ( 0.021 ms): perf/4150 ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument 0.023 ( 0.002 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1 ) ... 0.025 ( ): probe:x86_pmu_hw_config:(ffffffff9c0065e1)) x86_pmu_hw_config ([kernel.kallsyms]) hsw_hw_config ([kernel.kallsyms]) x86_pmu_event_init ([kernel.kallsyms]) perf_try_init_event ([kernel.kallsyms]) perf_event_alloc ([kernel.kallsyms]) SYSC_perf_event_open ([kernel.kallsyms]) sys_perf_event_open ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) return_from_SYSCALL_64 ([kernel.kallsyms]) syscall (/usr/lib64/libc-2.24.so) perf_event_attr__set_max_precise_ip (/home/acme/bin/perf) perf_evsel__new_cycles (/home/acme/bin/perf) perf_evlist__add_default (/home/acme/bin/perf) cmd_record (/home/acme/bin/perf) run_builtin (/home/acme/bin/perf) handle_internal_command (/home/acme/bin/perf) 0.023 ( 0.004 ms): perf/4150 ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument 0.028 ( 0.002 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1 ) ... 0.030 ( ): probe:x86_pmu_hw_config:(ffffffff9c0065e1)) x86_pmu_hw_config ([kernel.kallsyms]) hsw_hw_config ([kernel.kallsyms]) x86_pmu_event_init ([kernel.kallsyms]) perf_try_init_event ([kernel.kallsyms]) perf_event_alloc ([kernel.kallsyms]) SYSC_perf_event_open ([kernel.kallsyms]) sys_perf_event_open ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) return_from_SYSCALL_64 ([kernel.kallsyms]) syscall (/usr/lib64/libc-2.24.so) perf_event_attr__set_max_precise_ip (/home/acme/bin/perf) perf_evsel__new_cycles (/home/acme/bin/perf) perf_evlist__add_default (/home/acme/bin/perf) cmd_record (/home/acme/bin/perf) run_builtin (/home/acme/bin/perf) handle_internal_command (/home/acme/bin/perf) 0.028 ( 0.004 ms): perf/4150 ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument 41.018 ( 0.012 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8b5dd0, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4 41.065 ( 0.011 ms): perf/4150 perf_event_open(attr_uptr: 0x3c7db78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4 41.080 ( 0.006 ms): perf/4150 perf_event_open(attr_uptr: 0x3c7db78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4 41.103 ( 0.010 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), group_fd: -1, flags: FD_CLOEXEC) = 4 41.115 ( 0.006 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 5 41.122 ( 0.004 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 6 41.128 ( 0.008 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ] # I.e. that return -EINVAL in x86_pmu_hw_config() is hit three times. So fix it by just setting attr.sample_period Now, after this patch: # perf trace --max-stack=2 -e perf_event_open,probe:x86_pmu_hw_config* perf record usleep 1 [ perf record: Woken up 1 times to write data ] 0.000 ( 0.017 ms): perf/8469 perf_event_open(attr_uptr: 0x7ffe36c27d10, pid: -1, cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 4 syscall (/usr/lib64/libc-2.24.so) perf_event_open_cloexec_flag (/home/acme/bin/perf) 0.050 ( 0.031 ms): perf/8469 perf_event_open(attr_uptr: 0x24ebb78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4 syscall (/usr/lib64/libc-2.24.so) perf_evlist__config (/home/acme/bin/perf) 0.092 ( 0.040 ms): perf/8469 perf_event_open(attr_uptr: 0x24ebb78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4 syscall (/usr/lib64/libc-2.24.so) perf_evlist__config (/home/acme/bin/perf) 0.143 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, cpu: -1, group_fd: -1 ) = 4 syscall (/usr/lib64/libc-2.24.so) perf_event_attr__set_max_precise_ip (/home/acme/bin/perf) 0.161 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), group_fd: -1, flags: FD_CLOEXEC) = 4 syscall (/usr/lib64/libc-2.24.so) perf_evsel__open (/home/acme/bin/perf) 0.171 ( 0.005 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 5 syscall (/usr/lib64/libc-2.24.so) perf_evsel__open (/home/acme/bin/perf) 0.180 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 6 syscall (/usr/lib64/libc-2.24.so) perf_evsel__open (/home/acme/bin/perf) 0.190 ( 0.005 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8 syscall (/usr/lib64/libc-2.24.so) perf_evsel__open (/home/acme/bin/perf) [ perf record: Captured and wrote 0.017 MB perf.data (7 samples) ] # The probe one called from perf_event_attr__set_max_precise_ip() works the first time, with attr.precise_ip = 3, wit hthe next ones being the per cpu ones for the cycles:ppp event. And here is the text from a report and alternative proposed patch by Thomas-Mich Richter: --- On s390 the counter and sampling facility do not support a precise IP skid level and sometimes returns EOPNOTSUPP when structure member precise_ip in struct perf_event_attr is not set to zero. On s390 commnd 'perf record -- true' fails with error EOPNOTSUPP. This happens only when no events are specified on command line. The functions called are ... --> perf_evlist__add_default --> perf_evsel__new_cycles --> perf_event_attr__set_max_precise_ip The last function determines the value of structure member precise_ip by invoking the perf_event_open() system call and checking the return code. The first successful open is the value for precise_ip. However the value is determined without setting member sample_period and indicates no sampling. On s390 the counter facility and sampling facility are different. The above procedure determines a precise_ip value of 3 using the counter facility. Later it uses the sampling facility with a value of 3 and fails with EOPNOTSUPP. --- v2: Older compilers (e.g. gcc 4.4.7) don't support referencing members of unnamed union members in the container struct initialization, so move from: struct perf_event_attr attr = { ... .sample_period = 1, }; to right after it as: struct perf_event_attr attr = { ... }; attr.sample_period = 1; v3: We need to reset .sample_period to 0 to let the users of perf_evsel__new_cycles() to properly setup attr.sample_period or attr.sample_freq. Reported by Ingo Molnar. Reported-and-Acked-by: Thomas-Mich Richter Acked-by: Hendrik Brueckner Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Fixes: 18e7a45af91a ("perf/x86: Reject non sampling events with precise_ip") Link: http://lkml.kernel.org/n/tip-yv6nnkl7tzqocrm0hl3x7vf1@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/tests/task-exit.c | 2 +- tools/perf/util/evsel.c | 12 ++++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/tools/perf/tests/task-exit.c b/tools/perf/tests/task-exit.c index 01a5ba2788c6..b0d005d295a9 100644 --- a/tools/perf/tests/task-exit.c +++ b/tools/perf/tests/task-exit.c @@ -82,7 +82,7 @@ int test__task_exit(int subtest __maybe_unused) evsel = perf_evlist__first(evlist); evsel->attr.task = 1; - evsel->attr.sample_freq = 0; + evsel->attr.sample_freq = 1; evsel->attr.inherit = 0; evsel->attr.watermark = 0; evsel->attr.wakeup_events = 1; diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 3be8c489884e..f7128c2a6386 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -263,8 +263,20 @@ struct perf_evsel *perf_evsel__new_cycles(void) struct perf_evsel *evsel; event_attr_init(&attr); + /* + * Unnamed union member, not supported as struct member named + * initializer in older compilers such as gcc 4.4.7 + * + * Just for probing the precise_ip: + */ + attr.sample_period = 1; perf_event_attr__set_max_precise_ip(&attr); + /* + * Now let the usual logic to set up the perf_event_attr defaults + * to kick in when we return and before perf_evsel__open() is called. + */ + attr.sample_period = 0; evsel = perf_evsel__new(&attr); if (evsel == NULL) -- 2.17.1