From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754904AbbCaP4s (ORCPT ); Tue, 31 Mar 2015 11:56:48 -0400 Received: from mail.kernel.org ([198.145.29.136]:53775 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753322AbbCaP4q (ORCPT ); Tue, 31 Mar 2015 11:56:46 -0400 Date: Tue, 31 Mar 2015 12:56:55 -0300 From: Arnaldo Carvalho de Melo To: David Ahern Cc: Yunlong Song , a.p.zijlstra@chello.nl, paulus@samba.org, mingo@redhat.com, linux-kernel@vger.kernel.org, wangnan0@huawei.com Subject: Re: [PATCH 3/9] perf sched replay: Alloc the memory of pid_to_task dynamically to adapt to the unexpected change of pid_max Message-ID: <20150331155655.GL9438@kernel.org> References: <1427809596-29559-1-git-send-email-yunlong.song@huawei.com> <1427809596-29559-4-git-send-email-yunlong.song@huawei.com> <551AB005.8080102@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <551AB005.8080102@gmail.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, Mar 31, 2015 at 08:32:37AM -0600, David Ahern escreveu: > On 3/31/15 7:46 AM, Yunlong Song wrote: > >- BUG_ON(pid >= MAX_PID); > >+ if (sched->pid_to_task == NULL) { > >+ if (sysctl__read_int("kernel/pid_max", &pid_max) < 0) > >+ pid_max = MAX_PID; > >+ BUG_ON((sched->pid_to_task = calloc(pid_max, sizeof(struct task_desc *))) == NULL); > >+ } > >+ BUG_ON(pid >= (unsigned long)pid_max); > so why the previous patch bumping the MAX_PID count if you move to dynamic > here? And shouldn't MAX_PID get dropped here as well? > So attached is what i put together last week; just have not had time to send > it out. Yunlong, can you please check/Ack this? - Arnaldo > >From 159dc732e0ad66d9151e93761bc9c685872e9fa4 Mon Sep 17 00:00:00 2001 > From: David Ahern > Date: Tue, 24 Mar 2015 16:57:10 -0400 > Subject: [PATCH 3/5] perf sched: Remove max pid assumption from perf-sched > > 'perf sched replay' currently fails on sparc64: > $ perf sched replay > run measurement overhead: 2475 nsecs > sleep measurement overhead: 56165 nsecs > the run test took 999705 nsecs > the sleep test took 1059270 nsecs > perf: builtin-sched.c:384: register_pid: Assertion `!(pid >= 65536)' failed. > Aborted > > The max pid limitation is removed by converting pid_to_task from a > pid based array to an intlist (rblist) with the pid as the index > and task_desc stored in the priv element. > > In the process pid is converted from a long int to int. > > Signed-off-by: David Ahern > --- > tools/perf/builtin-sched.c | 30 ++++++++++++++++++++---------- > 1 file changed, 20 insertions(+), 10 deletions(-) > > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c > index cc52c993a1fa..858d85396d81 100644 > --- a/tools/perf/builtin-sched.c > +++ b/tools/perf/builtin-sched.c > @@ -33,13 +33,12 @@ > #define MAX_CPUS 4096 > #define COMM_LEN 20 > #define SYM_LEN 129 > -#define MAX_PID 65536 > > struct sched_atom; > > struct task_desc { > unsigned long nr; > - unsigned long pid; > + int pid; > char comm[COMM_LEN]; > > unsigned long nr_events; > @@ -129,7 +128,7 @@ struct perf_sched { > struct perf_tool tool; > const char *sort_order; > unsigned long nr_tasks; > - struct task_desc *pid_to_task[MAX_PID]; > + struct intlist *pid_to_task; > struct task_desc **tasks; > const struct trace_sched_handler *tp_handler; > pthread_mutex_t start_work_mutex; > @@ -377,14 +376,18 @@ static void add_sched_event_sleep(struct perf_sched *sched, struct task_desc *ta > } > > static struct task_desc *register_pid(struct perf_sched *sched, > - unsigned long pid, const char *comm) > + int pid, const char *comm) > { > - struct task_desc *task; > > - BUG_ON(pid >= MAX_PID); > + struct int_node *node = intlist__findnew(sched->pid_to_task, pid); > + struct task_desc *task; > > - task = sched->pid_to_task[pid]; > + if (node == NULL) { > + pr_err("Failed to allocate entry for task\n"); > + return NULL; > + } > > + task = (struct task_desc *) node->priv; > if (task) > return task; > > @@ -392,20 +395,21 @@ static struct task_desc *register_pid(struct perf_sched *sched, > task->pid = pid; > task->nr = sched->nr_tasks; > strcpy(task->comm, comm); > + > /* > * every task starts in sleeping state - this gets ignored > * if there's no wakeup pointing to this sleep state: > */ > add_sched_event_sleep(sched, task, 0, 0); > > - sched->pid_to_task[pid] = task; > + node->priv = task; > sched->nr_tasks++; > sched->tasks = realloc(sched->tasks, sched->nr_tasks * sizeof(struct task_task *)); > BUG_ON(!sched->tasks); > sched->tasks[task->nr] = task; > > if (verbose) > - printf("registered task #%ld, PID %ld (%s)\n", sched->nr_tasks, pid, comm); > + printf("registered task #%ld, PID %d (%s)\n", sched->nr_tasks, pid, comm); > > return task; > } > @@ -418,7 +422,7 @@ static void print_task_traces(struct perf_sched *sched) > > for (i = 0; i < sched->nr_tasks; i++) { > task = sched->tasks[i]; > - printf("task %6ld (%20s:%10ld), nr_events: %ld\n", > + printf("task %6ld (%20s:%10d), nr_events: %ld\n", > task->nr, task->comm, task->pid, task->nr_events); > } > } > @@ -2981,6 +2985,12 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused) > }; > unsigned int i; > > + sched.pid_to_task = intlist__new(NULL); > + if (sched.pid_to_task == NULL) { > + pr_err("Failed to allocate intlist for tracking tasks\n"); > + return -ENOMEM; > + } > + > for (i = 0; i < ARRAY_SIZE(sched.curr_pid); i++) > sched.curr_pid[i] = -1; > > -- > 2.3.0 >