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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9FFB7C433EF for ; Wed, 20 Jul 2022 15:47:58 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Lp0TT1Sw9z3chT for ; Thu, 21 Jul 2022 01:47:57 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=sIAZtEgu; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=google.com (client-ip=2a00:1450:4864:20::32a; helo=mail-wm1-x32a.google.com; envelope-from=irogers@google.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=sIAZtEgu; dkim-atps=neutral Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Lp0Sr2k2Vz2xrj for ; Thu, 21 Jul 2022 01:47:23 +1000 (AEST) Received: by mail-wm1-x32a.google.com with SMTP id j29-20020a05600c1c1d00b003a2fdafdefbso1536841wms.2 for ; Wed, 20 Jul 2022 08:47:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=mWnAaZCfU7C7OmxHqnYWgl+iLsNs720nTVq22EtgHY0=; b=sIAZtEguKhFTVPEcL45Kz2Y7TjZTXwniuvUqVOFt6zTUcFdJADS0J8AqBdnyMplZjY exEHIpC5cGIigKdZRLIrpUGSld8LfBC+X94IatTDzW+dLDf1k6TIHWW6ATZVIngS1Oos nXNorTzk3OQ+4Bw6EpGvQnLBrkMxd5it3oR2PPezjhMG5Q19ijxeGtIEqA74Qr5sjlGW N88s/rNDien3FWAJVSLrlCkT2frzA2AlziXYuogGSjxppzEPV90/SDc6MNYJGwkKv/to DVOUTZLRibFdeN8jUFaxX1PaFm9GcCgplfvOEKFNijKoimUdpo/tP/OlK08U7ey7KuN7 RXiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mWnAaZCfU7C7OmxHqnYWgl+iLsNs720nTVq22EtgHY0=; b=KtejXRJktNtyBuDw+zUpJGSTkhtuAFzGgaqiWz7VOZ5tOJ/7XeWD+XeOR1bs/DsT5J wJ8mRMblS9XY51z0JXLsOPwHJXvNSWyyIdDWyxT7LHAtl27xF2fdh1vhM80HllZX8K9V pJXAxCXtgQHxHQilScgTwix07qgVwygXeI+1BuC4RNcBa0OYhX6VV5foc/b+1crDQvOW L5uyAd/x7eoc6NfiNaF9vbXlA106r25JwxYqXyJ8w+AQwt3Mnnn6H79SFPsaND5+mum8 4Z8hY+Nne04k+vNSs8tbnazz8C4aJz558+KBB+X7EBJQJDCMTQz+C/Q9qBfPRC2ENGAF /POw== X-Gm-Message-State: AJIora9TUP/lZ3uyBuG5ajDj8jJi8KRyENYGRSENxKhXM569hTNDDLvO 5IynH8HXLB/z3hvDUmJkjBZRI9++FXbLAmZfkneZcA== X-Google-Smtp-Source: AGRyM1uVihkw2Sdalue9OE0oAHLSWWUsyLw0DH9Y+XMIaKbggZq5DpgzwDU0hZoWHWE5Iq2mk7j/ulCfYP4kQSqFlzU= X-Received: by 2002:a7b:ce13:0:b0:3a3:102c:23d3 with SMTP id m19-20020a7bce13000000b003a3102c23d3mr4391193wmc.67.1658332040566; Wed, 20 Jul 2022 08:47:20 -0700 (PDT) MIME-Version: 1.0 References: <20220704150514.48816-1-elver@google.com> In-Reply-To: From: Ian Rogers Date: Wed, 20 Jul 2022 08:47:08 -0700 Message-ID: Subject: Re: [PATCH v3 00/14] perf/hw_breakpoint: Optimize for thousands of tasks To: Marco Elver Content-Type: text/plain; charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-sh@vger.kernel.org, Peter Zijlstra , Frederic Weisbecker , x86@kernel.org, linuxppc-dev@lists.ozlabs.org, Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexander Shishkin , kasan-dev@googlegroups.com, Namhyung Kim , Thomas Gleixner , Jiri Olsa , Ingo Molnar , Dmitry Vyukov Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Jul 12, 2022 at 6:41 AM Marco Elver wrote: > > On Mon, 4 Jul 2022 at 17:05, Marco Elver wrote: > > > > The hw_breakpoint subsystem's code has seen little change in over 10 > > years. In that time, systems with >100s of CPUs have become common, > > along with improvements to the perf subsystem: using breakpoints on > > thousands of concurrent tasks should be a supported usecase. > [...] > > Marco Elver (14): > > perf/hw_breakpoint: Add KUnit test for constraints accounting > > perf/hw_breakpoint: Provide hw_breakpoint_is_used() and use in test > > perf/hw_breakpoint: Clean up headers > > perf/hw_breakpoint: Optimize list of per-task breakpoints > > perf/hw_breakpoint: Mark data __ro_after_init > > perf/hw_breakpoint: Optimize constant number of breakpoint slots > > perf/hw_breakpoint: Make hw_breakpoint_weight() inlinable > > perf/hw_breakpoint: Remove useless code related to flexible > > breakpoints > > powerpc/hw_breakpoint: Avoid relying on caller synchronization > > locking/percpu-rwsem: Add percpu_is_write_locked() and > > percpu_is_read_locked() > > perf/hw_breakpoint: Reduce contention with large number of tasks > > perf/hw_breakpoint: Introduce bp_slots_histogram > > perf/hw_breakpoint: Optimize max_bp_pinned_slots() for CPU-independent > > task targets > > perf/hw_breakpoint: Optimize toggle_bp_slot() for CPU-independent task > > targets > [...] > > This is ready from our side, and given the silence, assume it's ready > to pick up and/or have a maintainer take a look. Since this is mostly > kernel/events, would -tip/perf/core be appropriate? These are awesome improvements, I've added my acked-by to every change. I hope we can pull these changes, as you say, into tip.git perf/core and get them into 5.20. Thanks, Ian > Thanks, > -- Marco