From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 10D2551C40; Tue, 21 Nov 2023 13:40:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OLRQMdk1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87374C433CC; Tue, 21 Nov 2023 13:40:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700574034; bh=SzEJSARPBu356MnqKuppWjOHsICMADRQevq4Qbw7fLE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=OLRQMdk1ttntlk5HgMqe1X6VIwSYnAkEzWqHWW0Ity5Z4JPORqmgTl99QXcoKLiQu +fZ+ZZJogC4pTjB4S6Mb1EMw+cVSNL3gMowOB1pzr19jcuA00B2zx3sJdtYrKUxiCI M5h0d8oLdwnFKckUondaPNxJhBK8uR8oNIoz0DS5VcWCsk2tOmYyUrDLDE2HW+bbVx 9eRalFATDp4mqlEPIX1eFfGGy4KRmIrJ0+XDhNT1hecYgsMZdIVrG6ojUy6yV5u5T6 8ONldjRV9AgPDwm0OQMPZnqMStqDT+LS3sNfS2X/vMcO009u1VJyo8CkcN0SSmCLju th5iBaTWQ0T4Q== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1r5QzQ-00F5sJ-3K; Tue, 21 Nov 2023 13:40:32 +0000 Date: Tue, 21 Nov 2023 13:40:31 +0000 Message-ID: <86pm03z0kw.wl-maz@kernel.org> From: Marc Zyngier To: Hector Martin , Arnaldo Carvalho de Melo , Ian Rogers , James Clark Cc: linux-perf-users@vger.kernel.org, LKML , Asahi Linux , Mark Rutland Subject: Re: [REGRESSION] Perf (userspace) broken on big.LITTLE systems since v6.5 In-Reply-To: <08f1f185-e259-4014-9ca4-6411d5c1bc65@marcan.st> References: <08f1f185-e259-4014-9ca4-6411d5c1bc65@marcan.st> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: marcan@marcan.st, acme@redhat.com, irogers@google.com, james.clark@arm.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, asahi@lists.linux.dev, mark.rutland@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false [Adding key people on Cc] On Tue, 21 Nov 2023 12:08:48 +0000, Hector Martin wrote: > > Perf broke on all Apple ARM64 systems (tested almost everything), and > according to maz also on Juno (so, probably all big.LITTLE) since v6.5. I can confirm that at least on 6.7-rc2, perf is pretty busted on any asymmetric ARM platform. It isn't clear what criteria is used to pick the PMU, but nothing works anymore. The saving grace in my case is that Debian still ships a 6.1 perftool package, but that's obviously not going to last. I'm happy to test potential fixes. M. -- Without deviation from the norm, progress is not possible.