From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7931C3DB339; Wed, 3 Jun 2026 18:16:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780510622; cv=none; b=ano3vI4SnRm8EC14NMhPWLslKQzqiB+7CtdSbIo3mXLHVeHgkoSMpiKGrdELtmXnd4yPjUJX2+7PZqMRJOXK+3ztnK4UrpTwayxaGfkrtnKdUj5gV2BXLFPbK6ZrsNBBy/RnSqaNhJoqhjeUUpruy6fXlaMObMGhtfZIJ4OqNWE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780510622; c=relaxed/simple; bh=7g7eSXNFd6x4zcH4Pn9AImxVzHQhVePOAWugkZSlJjg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SIOuQadGFcemzgMVDPeQGffC//56F+Irm21NKV8GIbfLvcWPcS9DT6OlKZmnI0/9XoCYr0P4oOiGrjNn9QXVR2b2ynbOFqP1VSyw7877J8Q/tfiIbUPRvfdvJoC6cYOm4+hEzJ3pe+aVbdeZea4rpRma3c0yt8T+1mGEv/2R0Ug= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=ef7nMb0E; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="ef7nMb0E" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8C4114759; Wed, 3 Jun 2026 11:16:53 -0700 (PDT) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EE8393F86F; Wed, 3 Jun 2026 11:16:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780510618; bh=7g7eSXNFd6x4zcH4Pn9AImxVzHQhVePOAWugkZSlJjg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ef7nMb0E/12bcYNdfNrimAlNTgIO5Hh/D+hGfpd1wQMciIW+L6sdey7AHanePjgGA LeGZso7Nz8eTNiupxyEMegCmZCPZvK2H/wQHJ7OtDm71XoWfD96dpOVpdBNdGT9itY AfIOaAuJc2W6AUR1LCrMFLxWSstgTsUdUJcgEWRw= Date: Wed, 3 Jun 2026 19:16:55 +0100 From: Leo Yan To: James Clark Cc: Suzuki K Poulose , Mike Leach , Arnaldo Carvalho de Melo , Namhyung Kim , Jiri Olsa , Ian Rogers , Amir Ayupov , Jonathan Corbet , Shuah Khan , Paschalis Mpeis , coresight@lists.linaro.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , linux-doc@vger.kernel.org Subject: Re: [PATCH v2 08/18] perf test cs-etm: Replace memcpy test with raw dump stress test Message-ID: <20260603181655.GK101133@e132581.arm.com> References: <20260602-james-cs-context-tracking-fix-v2-0-85b5ce6f55c6@linaro.org> <20260602-james-cs-context-tracking-fix-v2-8-85b5ce6f55c6@linaro.org> <20260603143622.GX101133@e132581.arm.com> <882922c0-042a-4108-bc2f-cec443d0db9f@linaro.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <882922c0-042a-4108-bc2f-cec443d0db9f@linaro.org> On Wed, Jun 03, 2026 at 05:11:30PM +0100, James Clark wrote: [...] > > I am not sure how we can map 2MiB trace data to 50MiB+ raw dump. This > > Why not? Decoding it is roughly equal to decompressing it, and with that > amount of trace the small differences in compressibility average out and you > do get the same amount every time. I think if we got less than half the > amount expected then it would be worth investigating. TBH, I don't know how to calculate decompressing size. Seems to me this is a heuristics value. Maybe Mike could help to confirm if this works or not. [...] > That would work, but that wouldn't be as thorough. The first thing it prints > is " CoreSight .* Trace data: size .* bytes". If it stops working half way > through or prints nothing then the test will still pass. > > The reason I wanted to add a stress test is because all of the other tests > have been reduced to just a few kb of trace so we have nothing that opens a > file with a more reasonable amount of data. > > I suppose with your suggestion we'd still check the exit code, but that's > about it. Is it possible to locate the end of raw dump with a specific parttern? like: Idx:36061; ID:1a; I_IGNORE : Ignore. Idx:36062; ID:1a; I_IGNORE : Ignore. Idx:36063; ID:1a; I_IGNORE : Ignore. Idx:36064; ID:1a; I_IGNORE : Ignore. Idx:36065; ID:1a; I_IGNORE : Ignore. Idx:36066; ID:1a; I_IGNORE : Ignore. Idx:36067; ID:1a; I_IGNORE : Ignore. Idx:36068; ID:1a; I_IGNORE : Ignore. Idx:36069; ID:1a; I_IGNORE : Ignore. Idx:36070; ID:1a; I_IGNORE : Ignore. Idx:36071; ID:1a; I_IGNORE : Ignore. Idx:36072; ID:1a; I_IGNORE : Ignore. Idx:36073; ID:1a; I_IGNORE : Ignore. Idx:36074; ID:1a; I_IGNORE : Ignore. Idx:36075; ID:1a; I_IGNORE : Ignore. Idx:36076; ID:1a; I_IGNORE : Ignore. Idx:36077; ID:1a; I_IGNORE : Ignore. Idx:36078; ID:1a; I_IGNORE : Ignore. Idx:36079; ID:1a; I_IGNORE : Ignore. Idx:36080; ID:1a; I_IGNORE : Ignore. Idx:36081; ID:1a; I_IGNORE : Ignore. Idx:36082; ID:1a; I_IGNORE : Ignore. Idx:36083; ID:1a; I_IGNORE : Ignore. Idx:36084; ID:1a; I_IGNORE : Ignore. Idx:36085; ID:1a; I_IGNORE : Ignore. Idx:36086; ID:1a; I_IGNORE : Ignore. Idx:36087; ID:1a; I_IGNORE : Ignore. Idx:36088; ID:1a; I_IGNORE : Ignore. Idx:36089; ID:1a; I_IGNORE : Ignore. Idx:36090; ID:1a; I_IGNORE : Ignore. Idx:36091; ID:1a; I_IGNORE : Ignore. Idx:36092; ID:1a; I_IGNORE : Ignore. Idx:36093; ID:1a; I_IGNORE : Ignore. Idx:36094; ID:1a; I_IGNORE : Ignore. Idx:36095; ID:1a; I_IGNORE : Ignore. Thanks, Leo