From patchwork Tue Apr 2 13:42:26 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Slavomir Kaslev X-Patchwork-Id: 10881751 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 55EE118E8 for ; Tue, 2 Apr 2019 13:43:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 424E528892 for ; Tue, 2 Apr 2019 13:43:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 373BC28895; Tue, 2 Apr 2019 13:43:02 +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 D28DA288A2 for ; Tue, 2 Apr 2019 13:43:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731884AbfDBNnB (ORCPT ); Tue, 2 Apr 2019 09:43:01 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:40018 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731879AbfDBNnA (ORCPT ); Tue, 2 Apr 2019 09:43:00 -0400 Received: by mail-wr1-f68.google.com with SMTP id h4so16701526wre.7 for ; Tue, 02 Apr 2019 06:42:59 -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=wGyYqYTaWp7jSzh02FXSmxuS07TS71n2orhCthe5OBo=; b=b8iYLivQW/3GZ2COWHJ7z82Fymj1qj27+DT+b94gbqzIZ+SmBZIJUTJYTXFQ0E0HSk DKSRkfqcBlroXK9PQ4X+S1ed77DcrraXXum7jeMnRYXIRjFNzdRO+D+yfCLOxCnnWDS5 9OrhD980iEPObIC7ePgIB6b35c36htbsC3yQps40yT8AwryoNYQL8koxK6OWtuuM6P4J 87JK5j9CRAfXYYWtDZ+9pAKFXMh9WDkTiw3+1A9vpfXlNKK6zx4CNJKJLsaHidvwIf6S dZESxWfM0i/TIBg3TntA14meM2BsW99VkoiwMGFYTGllRL/QGXAIKoqrN99PrF8Yqxu4 Uxhw== X-Gm-Message-State: APjAAAVfyLFV1w+n7nPgCeOOSPHOv1VqbY9GELMXaJS4dIB8Y0tHIiLZ ZYig4Wsl4SeFMkZmisHA9jbcDTd+vw== X-Google-Smtp-Source: APXvYqze7+EurR6bHbP3zNjLkG15g+L+tE2w+DPFo810qrStk/lyOpArTDFg+MPslloq9F4fysSMvQ== X-Received: by 2002:a5d:6a4f:: with SMTP id t15mr45375064wrw.156.1554212578538; Tue, 02 Apr 2019 06:42:58 -0700 (PDT) Received: from box.eng.vmware.com ([146.247.46.5]) by smtp.gmail.com with ESMTPSA id h84sm19207083wmf.15.2019.04.02.06.42.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Apr 2019 06:42:57 -0700 (PDT) From: Slavomir Kaslev To: rostedt@goodmis.org, linux-trace-devel@vger.kernel.org Cc: slavomir.kaslev@gmail.com Subject: [RFC PATCH v8 10/13] trace-cmd: Try to autodetect number of guest CPUs in setup-guest if not specified Date: Tue, 2 Apr 2019 16:42:26 +0300 Message-Id: <20190402134230.30988-21-kaslevs@vmware.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190402134230.30988-1-kaslevs@vmware.com> References: <20190402134230.30988-1-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 When no number of guest CPUs is provided with the -c flag to `trace-cmd setup-guest`, try to autodetect it using virsh for libvirt managed guests. Signed-off-by: Slavomir Kaslev --- tracecmd/trace-setup-guest.c | 21 +++++++++++++++++++++ tracecmd/trace-usage.c | 2 +- 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/tracecmd/trace-setup-guest.c b/tracecmd/trace-setup-guest.c index 5e66551..15ec637 100644 --- a/tracecmd/trace-setup-guest.c +++ b/tracecmd/trace-setup-guest.c @@ -93,6 +93,24 @@ static int make_guest_fifos(const char *guest, int nr_cpus, mode_t mode) return ret; } +static int get_guest_cpu_count(const char *guest) +{ + const char *cmd_fmt = "virsh vcpucount --maximum '%s' 2>/dev/null"; + int nr_cpus = -1; + char cmd[1024]; + FILE *f; + + snprintf(cmd, sizeof(cmd), cmd_fmt, guest); + f = popen(cmd, "r"); + if (!f) + return -errno; + + fscanf(f, "%d", &nr_cpus); + pclose(f); + + return nr_cpus; +} + static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gid) { gid_t save_egid; @@ -171,6 +189,9 @@ void trace_setup_guest(int argc, char **argv) guest = argv[optind+1]; + if (nr_cpus <= 0) + nr_cpus = get_guest_cpu_count(guest); + if (nr_cpus <= 0) pdie("invalid number of cpus for guest %s", guest); diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c index 7a8002f..9a13d93 100644 --- a/tracecmd/trace-usage.c +++ b/tracecmd/trace-usage.c @@ -249,7 +249,7 @@ static struct usage_help usage_help[] = { { "setup-guest", "create FIFOs for tracing guest VMs", - " %s setup-guest -c cpus[-p perm][-g group] guest\n" + " %s setup-guest [-c cpus][-p perm][-g group] guest\n" " -c number of guest virtual CPUs\n" " -p FIFOs permissions (default: 0660)\n" " -g FIFOs group owner\n"