From patchwork Wed Apr 17 13:09:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Slavomir Kaslev X-Patchwork-Id: 10905317 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E47D417E0 for ; Wed, 17 Apr 2019 13:10:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CCAAC285E0 for ; Wed, 17 Apr 2019 13:10:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C0A69287C9; Wed, 17 Apr 2019 13:10:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2826C287C9 for ; Wed, 17 Apr 2019 13:10:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729940AbfDQNKO (ORCPT ); Wed, 17 Apr 2019 09:10:14 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:39995 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726800AbfDQNKN (ORCPT ); Wed, 17 Apr 2019 09:10:13 -0400 Received: by mail-wm1-f67.google.com with SMTP id z24so3549208wmi.5 for ; Wed, 17 Apr 2019 06:10:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=6GiBiUljA8IUa0lL0JwcJ4NVuYMWI5gvpRyMp9EWdE0=; b=Jv/SBNEEDaujN9xSswRcWTAa4sQWsJuVxDUdbDyl9tIB2Za3CiGj/WLD/PlYyIl1lK 1QohhKjFNQ4T6AO0hxK5FZqV20iAW3os4eaG8z+qkNjDGzmFkxwUtcrMgW0+IDODXBdK yGtJk35g21LIQBWdrtKLQj+1Zmjb/Fvz2pOLFLR89QZvFBnePQBtaSN/HeE4Jy8ALkr7 hghtFcuaNYjpJonjLf6f54cD8+j/gQmuf5ixg04fuALcLAAq9kaASvqxnC5nJthwHxo1 d5Snhi0EY56YIZ3wVmfCZfIIzhJPvXtnJ3WcDfAXLDXZAOM7QIa+mN5EF5zVyuYO9fAI Wufg== X-Gm-Message-State: APjAAAVbqMJXjlHhCDXTfiIs/ZZfGRGW/wDzfjhVHvh7Ao0Q3JOabfNb FcrwnvInQNjOzpDhJR4VwQ== X-Google-Smtp-Source: APXvYqw8xW5MHvFJf1jXLpAMUNM3kqUM+f50HrmdNHH8T5Ajg782l1JSTed6hspubhk1rgYele3Tlg== X-Received: by 2002:a1c:7f10:: with SMTP id a16mr32018025wmd.30.1555506611301; Wed, 17 Apr 2019 06:10:11 -0700 (PDT) Received: from localhost.localdomain ([151.251.252.188]) by smtp.gmail.com with ESMTPSA id d16sm48124303wrs.68.2019.04.17.06.10.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Apr 2019 06:10:07 -0700 (PDT) From: Slavomir Kaslev To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org, pauld@redhat.com, ykaradzhov@vmware.com, jbacik@fb.com, tstoyanov@vmware.com, slavomir.kaslev@gmail.com Subject: [PATCH v4 1/2] trace-cmd: Optimize how pid filters are expressed Date: Wed, 17 Apr 2019 16:09:58 +0300 Message-Id: <20190417130959.10064-2-kaslevs@vmware.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190417130959.10064-1-kaslevs@vmware.com> References: <20190417130959.10064-1-kaslevs@vmware.com> MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Express pid filters as allowed/disallowed filter ranges (pid>=100&&pid<=103) instead of specifying them per pid (pid==100||pid==101||pid==102||pid==103) This makes the size of the resulting filter smaller (and faster) and avoids overflowing the filter size limit of one page which we can hit on bigger machines (say >160 CPUs). Signed-off-by: Slavomir Kaslev Reported-by: Phil Auld Suggested-by: Steven Rostedt (VMware) Tested-by: Phil Auld --- tracecmd/trace-record.c | 117 +++++++++++++++++++++++++++------------- 1 file changed, 81 insertions(+), 36 deletions(-) diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c index a3a34f1..4523128 100644 --- a/tracecmd/trace-record.c +++ b/tracecmd/trace-record.c @@ -951,10 +951,63 @@ static void update_ftrace_pids(int reset) static void update_event_filters(struct buffer_instance *instance); static void update_pid_event_filters(struct buffer_instance *instance); +static void append_filter_pid_range(char **filter, int *curr_len, + const char *field, + int start_pid, int end_pid, bool exclude) +{ + const char *op = "", *op1, *op2, *op3; + int len; + + if (*filter && **filter) + op = exclude ? "&&" : "||"; + + /* Handle thus case explicitly so that we get `pid==3` instead of + * `pid>=3&&pid<=3` for singleton ranges + */ + if (start_pid == end_pid) { +#define FMT "%s(%s%s%d)" + len = snprintf(NULL, 0, FMT, op, + field, exclude ? "!=" : "==", start_pid); + *filter = realloc(*filter, *curr_len + len + 1); + if (!*filter) + die("realloc"); + + len = snprintf(*filter + *curr_len, len + 1, FMT, op, + field, exclude ? "!=" : "==", start_pid); + *curr_len += len; + + return; +#undef FMT + } + + if (exclude) { + op1 = "<"; + op2 = "||"; + op3 = ">"; + } else { + op1 = ">="; + op2 = "&&"; + op3 = "<="; + } + +#define FMT "%s(%s%s%d%s%s%s%d)" + len = snprintf(NULL, 0, FMT, op, + field, op1, start_pid, op2, + field, op3, end_pid); + *filter = realloc(*filter, *curr_len + len + 1); + if (!*filter) + die("realloc"); + + len = snprintf(*filter + *curr_len, len + 1, FMT, op, + field, op1, start_pid, op2, + field, op3, end_pid); + *curr_len += len; +} + /** * make_pid_filter - create a filter string to all pids against @field * @curr_filter: Append to a previous filter (may realloc). Can be NULL - * @field: The fild to compare the pids against + * @field: The field to compare the pids against * * Creates a new string or appends to an existing one if @curr_filter * is not NULL. The new string will contain a filter with all pids @@ -964,54 +1017,46 @@ static void update_pid_event_filters(struct buffer_instance *instance); */ static char *make_pid_filter(char *curr_filter, const char *field) { + int start_pid = -1, last_pid = -1; + int last_exclude = -1; struct filter_pids *p; - char *filter; - char *orit; - char *match; - char *str; + char *filter = NULL; int curr_len = 0; - int len; /* Use the new method if possible */ if (have_set_event_pid) return NULL; - len = len_filter_pids + (strlen(field) + strlen("(==)||")) * nr_filter_pids; - - if (curr_filter) { - curr_len = strlen(curr_filter); - filter = realloc(curr_filter, curr_len + len + strlen("(&&())")); - if (!filter) - die("realloc"); - memmove(filter+1, curr_filter, curr_len); - filter[0] = '('; - strcat(filter, ")&&("); - curr_len = strlen(filter); - } else - filter = malloc(len); - if (!filter) - die("Failed to allocate pid filter"); - - /* Last '||' that is not used will cover the \0 */ - str = filter + curr_len; + if (!filter_pids) + return curr_filter; for (p = filter_pids; p; p = p->next) { - if (p->exclude) { - match = "!="; - orit = "&&"; - } else { - match = "=="; - orit = "||"; + /* + * PIDs are inserted in `filter_pids` from the front and that's + * why we expect them in descending order here. + */ + if (p->pid == last_pid - 1 && p->exclude == last_exclude) { + last_pid = p->pid; + continue; } - if (p == filter_pids) - orit = ""; - len = sprintf(str, "%s(%s%s%d)", orit, field, match, p->pid); - str += len; + if (start_pid != -1) + append_filter_pid_range(&filter, &curr_len, field, + last_pid, start_pid, + last_exclude); + + start_pid = last_pid = p->pid; + last_exclude = p->exclude; + } + append_filter_pid_range(&filter, &curr_len, field, + last_pid, start_pid, last_exclude); - if (curr_len) - sprintf(str, ")"); + if (curr_filter) { + char *save = filter; + asprintf(&filter, "(%s)&&(%s)", curr_filter, filter); + free(save); + } return filter; }