From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACFB9CA9ECB for ; Thu, 31 Oct 2019 20:31:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76FDF20656 for ; Thu, 31 Oct 2019 20:31:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="mABEo0zY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729742AbfJaUao (ORCPT ); Thu, 31 Oct 2019 16:30:44 -0400 Received: from linux.microsoft.com ([13.77.154.182]:44404 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726741AbfJaUan (ORCPT ); Thu, 31 Oct 2019 16:30:43 -0400 Received: by linux.microsoft.com (Postfix, from userid 1040) id D4EE720B7192; Thu, 31 Oct 2019 13:30:41 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D4EE720B7192 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1572553841; bh=QC5IgGNX+K4lVNk5r7CO7rrQsO2IiDjy89D6wZ29yao=; h=From:To:Cc:Subject:Date:From; b=mABEo0zYKzYzi4Eq8fYMg1nmLPNjv8cm6B8HL8F5JSjSSKQBh8O6TeOtjiRap2lTp WG+6t2Xu44TZ/prmYeQNicUvEOoVt1WLFWZoCYzN0lBqC1nMCDRib4hyU5dU6MIVQp 7TOZJKntn6qA1qVjJj9UdRRo36aQjQ/jYwUWd6mk= From: Steve MacLean Cc: Steve MacLean , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Stephane Eranian , linux-kernel@vger.kernel.org Subject: [PATCH v3] perf inject --jit: Remove //anon mmap events Date: Thu, 31 Oct 2019 13:30:36 -0700 Message-Id: <1572553836-32361-1-git-send-email-steve.maclean@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steve MacLean While a JIT is jitting code it will eventually need to commit more pages and change these pages to executable permissions. Typically the JIT will want these colocated to minimize branch displacements. The kernel will coalesce these anonymous mapping with identical permissions before sending an MMAP event for the new pages. This means the mmap event for the new pages will include the older pages. These anonymous mmap events will obscure the jitdump injected pseudo events. This means that the jitdump generated symbols, machine code, debugging info, and unwind info will no longer be used. Observations: When a process emits a jit dump marker and a jitdump file, the perf-xxx.map file represents inferior information which has been superceded by the jitdump jit-xxx.dump file. Further the '//anon*' mmap events are only required for the legacy perf-xxx.map mapping. When attaching to an existing process, the synthetic anon map events are given a time stamp of -1. These should not obscure the jitdump events which have an actual time. Summary: Use thread->priv to store whether a jitdump file has been processed During "perf inject --jit", discard "//anon*" mmap events for any pid which has sucessfully processed a jitdump file. Committer testing: // jitdump case perf record perf inject --jit --input perf.data --output perfjit.data // verify mmap "//anon" events present initially perf script --input perf.data --show-mmap-events | grep '//anon' // verify mmap "//anon" events removed perf script --input perfjit.data --show-mmap-events | grep '//anon' // no jitdump case perf record perf inject --jit --input perf.data --output perfjit.data // verify mmap "//anon" events present initially perf script --input perf.data --show-mmap-events | grep '//anon' // verify mmap "//anon" events not removed perf script --input perfjit.data --show-mmap-events | grep '//anon' Repro: This issue was discovered while testing the initial CoreCLR jitdump implementation. https://github.com/dotnet/coreclr/pull/26897. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Mark Rutland Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Cc: linux-kernel@vger.kernel.org Signed-off-by: Steve MacLean --- tools/perf/builtin-inject.c | 4 ++-- tools/perf/util/jitdump.c | 31 ++++++++++++++++++++++++++++++- 2 files changed, 32 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index 372ecb3..0f38862 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -263,7 +263,7 @@ static int perf_event__jit_repipe_mmap(struct perf_tool *tool, * if jit marker, then inject jit mmaps and generate ELF images */ ret = jit_process(inject->session, &inject->output, machine, - event->mmap.filename, sample->pid, &n); + event->mmap.filename, event->mmap.pid, &n); if (ret < 0) return ret; if (ret) { @@ -301,7 +301,7 @@ static int perf_event__jit_repipe_mmap2(struct perf_tool *tool, * if jit marker, then inject jit mmaps and generate ELF images */ ret = jit_process(inject->session, &inject->output, machine, - event->mmap2.filename, sample->pid, &n); + event->mmap2.filename, event->mmap2.pid, &n); if (ret < 0) return ret; if (ret) { diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c index e3ccb0c..d18596e 100644 --- a/tools/perf/util/jitdump.c +++ b/tools/perf/util/jitdump.c @@ -26,6 +26,7 @@ #include "jit.h" #include "jitdump.h" #include "genelf.h" +#include "thread.h" #include #include @@ -749,6 +750,28 @@ static int jit_repipe_debug_info(struct jit_buf_desc *jd, union jr_entry *jr) return 0; } +static void jit_add_pid(struct machine *machine, pid_t pid) +{ + struct thread *thread = machine__findnew_thread(machine, pid, pid); + + if (!thread) { + pr_err("%s: thread %d not found or created\n", __func__, pid); + return; + } + + thread->priv = (void *)1; +} + +static bool jit_has_pid(struct machine *machine, pid_t pid) +{ + struct thread *thread = machine__find_thread(machine, pid, pid); + + if (!thread) + return 0; + + return (bool)thread->priv; +} + int jit_process(struct perf_session *session, struct perf_data *output, @@ -764,8 +787,13 @@ static int jit_repipe_debug_info(struct jit_buf_desc *jd, union jr_entry *jr) /* * first, detect marker mmap (i.e., the jitdump mmap) */ - if (jit_detect(filename, pid)) + if (jit_detect(filename, pid)) { + // Strip //anon* mmaps if we processed a jitdump for this pid + if (jit_has_pid(machine, pid) && (strncmp(filename, "//anon", 6) == 0)) + return 1; + return 0; + } memset(&jd, 0, sizeof(jd)); @@ -784,6 +812,7 @@ static int jit_repipe_debug_info(struct jit_buf_desc *jd, union jr_entry *jr) ret = jit_inject(&jd, filename); if (!ret) { + jit_add_pid(machine, pid); *nbytes = jd.bytes_written; ret = 1; } -- 1.8.3.1