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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85A15EB64DC for ; Thu, 15 Jun 2023 16:44:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232208AbjFOQnz (ORCPT ); Thu, 15 Jun 2023 12:43:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235592AbjFOQnb (ORCPT ); Thu, 15 Jun 2023 12:43:31 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14A4B2711 for ; Thu, 15 Jun 2023 09:42:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1686847362; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Rj+HZrGceh1/5T+xxc4svlJVZP7112zLUTsVEWs0gK0=; b=aSEEE4SEwpMPLB8GMloJ8193FCXEB3fb6uHAYnUy1c8uqxa3GTxKYs52cO6MpbXwLFj8Ps XZBwtGD5b7MsyiLnGREn36Hvmc3eleggDOl7qVF/kxHk92dKO87/KO0Ael4S822sw1kzzb cFTD6shNXUX39Jhr4y9bJUQZuACKLtI= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-120-FAMA0aw8NICTg3T5oAVoOw-1; Thu, 15 Jun 2023 12:42:39 -0400 X-MC-Unique: FAMA0aw8NICTg3T5oAVoOw-1 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-3110f149dd5so819232f8f.1 for ; Thu, 15 Jun 2023 09:42:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686847358; x=1689439358; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Rj+HZrGceh1/5T+xxc4svlJVZP7112zLUTsVEWs0gK0=; b=JNKTXq1uozVgPhEGONw+tHREe5q1ONBkXhM08Wq7gNDbS53yekJOiyte6YXa2vYe2Z nAHENYXE9QLRqTbL2Rj2nohJ2dEhh2N9mbSCXq9AdpFc2EJsZ+yIHwdROyADROgFdYzS Yl0Rfr73SmfZDscc7QuefAv6UCx6gSatJDhpL6cWtMcld78D27o1zqg6sKCgX/C/5K/X OyGPznrHYbzTimUfWxcd6yAmS8LtyPoSBl9pc0YFpvmSjgW/jsJPbOlMA+aoxNBS7NFD 0qXSMAaaCDRcpt0yUl02Ag/p/5UrhzAvvBsDufyOFZXAKFfWrY+P+QHVine4HUo3fvLW Lw6Q== X-Gm-Message-State: AC+VfDwk84S4bYPIHYXuThhNW0aPnMfu2P0VMYm4/ROOyKBc72p9TqQE dKXaeCZRcAJtfiVtcmn+w5EaYbbeU89tYvJI4B+LA5+XfcylPCrXwvv+R2mkKSFgyNmaVmrGnL9 VueheRGYdBSfqtCp22ZKxfGgt X-Received: by 2002:a5d:6949:0:b0:311:101f:6c17 with SMTP id r9-20020a5d6949000000b00311101f6c17mr3191745wrw.2.1686847358414; Thu, 15 Jun 2023 09:42:38 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ6huGVDbjkL6h5ZmquE64pBw+y8CBHR4bn2cBEEEyfJXfF0yPF+idvDgy8YSHCA8GN8yo54TA== X-Received: by 2002:a5d:6949:0:b0:311:101f:6c17 with SMTP id r9-20020a5d6949000000b00311101f6c17mr3191731wrw.2.1686847358091; Thu, 15 Jun 2023 09:42:38 -0700 (PDT) Received: from vschneid.remote.csb ([154.57.232.159]) by smtp.gmail.com with ESMTPSA id q7-20020adff947000000b0030af72bca98sm21375624wrr.103.2023.06.15.09.42.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Jun 2023 09:42:37 -0700 (PDT) From: Valentin Schneider To: Leonardo Bras , Steven Rostedt , Masami Hiramatsu , Leonardo Bras , Peter Zijlstra , "Paul E. McKenney" , Juergen Gross , Yury Norov , Sebastian Andrzej Siewior Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [RFC PATCH v5 1/2] trace,smp: Add tracepoints around remotelly called functions In-Reply-To: <20230615065944.188876-5-leobras@redhat.com> References: <20230615065944.188876-3-leobras@redhat.com> <20230615065944.188876-5-leobras@redhat.com> Date: Thu, 15 Jun 2023 17:42:36 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15/06/23 03:59, Leonardo Bras wrote: > The recently added ipi_send_{cpu,cpumask} tracepoints allow finding sources > of IPIs targeting CPUs running latency-sensitive applications. > > For NOHZ_FULL CPUs, all IPIs are interference, and those tracepoints are > sufficient to find them and work on getting rid of them. In some setups > however, not *all* IPIs are to be suppressed, but long-running IPI > callbacks can still be problematic. > > Add a pair of tracepoints to mark the start and end of processing a CSD IPI > callback, similar to what exists for softirq, workqueue or timer callbacks. > > Signed-off-by: Leonardo Bras Tested-and-reviewed-by: Valentin Schneider