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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25B95C433EF for ; Sat, 9 Oct 2021 00:21:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F010D60FD7 for ; Sat, 9 Oct 2021 00:21:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243990AbhJIAXa (ORCPT ); Fri, 8 Oct 2021 20:23:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243892AbhJIAX3 (ORCPT ); Fri, 8 Oct 2021 20:23:29 -0400 Received: from smtp.gentoo.org (smtp.gentoo.org [IPv6:2001:470:ea4a:1:5054:ff:fec7:86e4]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A881C061570 for ; Fri, 8 Oct 2021 17:21:33 -0700 (PDT) Received: from grubbs.orbis-terrarum.net (localhost [127.0.0.1]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by smtp.gentoo.org (Postfix) with ESMTPS id 233063430EF for ; Sat, 9 Oct 2021 00:21:30 +0000 (UTC) Received: (qmail 561 invoked by uid 10000); 9 Oct 2021 00:21:29 -0000 Date: Sat, 9 Oct 2021 00:21:29 +0000 From: "Robin H. Johnson" To: Steven Rostedt Cc: "Robin H. Johnson" , Peter Zijlstra , linux-kernel@vger.kernel.org, mingo@redhat.com, rjohnson@digitalocean.com, Arnaldo Carvalho de Melo Subject: Re: [PATCH 1/2] tracing: show size of requested buffer Message-ID: References: <20210831043723.13481-1-robbat2@gentoo.org> <20210907212426.73ed81d1@rorschach.local.home> <20211007071151.GL174703@worktop.programming.kicks-ass.net> <20211007092358.65152792@gandalf.local.home> <20211008181348.4c2488b7@gandalf.local.home> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="kfJPulgMX8wmlwUv" Content-Disposition: inline In-Reply-To: <20211008181348.4c2488b7@gandalf.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --kfJPulgMX8wmlwUv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 08, 2021 at 06:13:48PM -0400, Steven Rostedt wrote: > On Thu, 7 Oct 2021 17:26:04 +0000 > "Robin H. Johnson" wrote: >=20 > > I was trying to think further what would make sense for the constant. > > - What are the negative impacts of a too-large value? > > - Is there demand for more reconfigurability?=20 > > - Should PERF_MAX_TRACE_SIZE be a knob in Kconfig? >=20 > One thing you haven't discussed was, have you hit this warning, and if so, > what were you doing? Ah, I covered that in patch 2/2 in the original series, which discussed why I was raising the limit, and how I came to the 8K value for PERF_MAX_TRACE_SIZE. https://lore.kernel.org/all/20210831043723.13481-2-robbat2@gentoo.org/ To summarize here: $work requires that all employees run endpoint security software from SentinalOne [1]. I can see that it uses trace/perf stuff to dig deeply into what's taking place on the system. Something in my personal setup/configuration, leads to SentinelOne getting large perf backlogs during heavy workloads, primarily when I'm doing deep things with containers (esp with tun devices inside containers). I haven't been able to narrow it down much more than that, and I don't have the source to SentinelOne at all. It does feel like SentinelOne either has a leak of some sort, or gets a backlog of work that takes a noticible amount of time to clean up. [1] https://www.sentinelone.com/ --=20 Robin Hugh Johnson Gentoo Linux: Dev, Infra Lead, Foundation Treasurer E-Mail : robbat2@gentoo.org GnuPG FP : 11ACBA4F 4778E3F6 E4EDF38E B27B944E 34884E85 GnuPG FP : 7D0B3CEB E9B85B1F 825BCECF EE05E6F6 A48F6136 --kfJPulgMX8wmlwUv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: Robbat2 @ Orbis-Terrarum Networks - The text below is a digital signature. 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