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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,T_MIXED_ES,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE0F2C67839 for ; Thu, 13 Dec 2018 13:10:24 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AC7D020849 for ; Thu, 13 Dec 2018 13:10:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="YJi7y7Iy"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="DwgYHu3D" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AC7D020849 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0HlhEEfVLNL1XnZO7YQZAEb+eAGXrTw2bxRh0yOXKxk=; b=YJi7y7IyTdNj+M vmOubEgApVhQF+9ifdcYDsyZQomILnT1ZyAah1FUtZTJrlJ+RJ34xi/j4A7zNlA1s++8mpzAqYdHW hKl2i4ngIQaa2NubCaYh6OhdAj2tC8ucWOpZ76DqXzYbvZn+uUqE87FOSkRPGON5ys1kD9dvarzrC sUUJJgK3DJVNOX/f9cUuICFX4vG83kJJyzw9/DXY3f45NZ1+yUKFAXF+wq8XuFsDux+JyHzQU+jPV 51g6aTdyWb7Ck5R0uhuR3dQkR+PSLJ5Y0P4Oh+ZoWIVeMgaS/XiFElJ2aDRv7P/8wNykdzTZHXCBx U6cARavPx4rS8EU9/qyQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gXQkx-0000Qt-Te; Thu, 13 Dec 2018 13:10:23 +0000 Received: from mail-wm1-x344.google.com ([2a00:1450:4864:20::344]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gXQku-000865-Ld for linux-arm-kernel@lists.infradead.org; Thu, 13 Dec 2018 13:10:22 +0000 Received: by mail-wm1-x344.google.com with SMTP id s14so2302896wmh.1 for ; Thu, 13 Dec 2018 05:10:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=38mbt+BqVhFnc/CjZGS2t6U4Vp7zJP4jXDTl/C7yvYY=; b=DwgYHu3D5WYQJRF4/72VhnR6oNXBOgmN/Uo1a62KHbYyC8jN6zL4KZNhUXO/c0OeCL pSGIakLqb8mRF+NG6S7fq9N6IdlyD27dYvw7u+csVxpsScCu+jYlDk8dQqyxGe54z4iI n+viNKVVnSNRk2DPDrVV/tdg5S4Xx0ei2a3Eg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=38mbt+BqVhFnc/CjZGS2t6U4Vp7zJP4jXDTl/C7yvYY=; b=rKTWzXJyPUxOMsULxCI92P0Y0QmT7r/3abUEsEPcPGlY1L5JVbKRQw8qYveBjZrnap My+El5RbDvch/MFXquziM4tDmjcRJpceD1XZtJSOG/5IpMEybEcc0R+5LLkbfSRgqRBf Uxtgi3nxvcZaZaZn8dxJ5RhXXXjfZJcQmsJ+sOQGDxWwbFqKczSvpKx9kgpINGwd+Yu6 rmc/XvbscNuCh3vCWgclS7iISqZqrVZJhpNtKb6Au7fyL6lbNFyvZWpiVmDbtakrUmj9 MrGBQsbBS7pg7WHCnTCrEOJ7DFBGWX+JEmuLROMFZRlAgqd401W8O3Q4ohu1WsS4OUVd 0JMg== X-Gm-Message-State: AA+aEWY2/8LWHpSdxTv6tCRXVrMi8a0gKCVHwgkYFXKVccFkEvrykxe4 AOsLc11iOmhI+aGJ7CNmatIhRw== X-Google-Smtp-Source: AFSGD/WyFLVEfjsdKtOcn9yelNWlk6saP74A/ECCNprpBA7mXmBpPy2H53+CUCvHQfsVKeb/aVqOaQ== X-Received: by 2002:a1c:b515:: with SMTP id e21mr10258132wmf.82.1544706608515; Thu, 13 Dec 2018 05:10:08 -0800 (PST) Received: from leoy-ThinkPad-X240s ([209.250.228.18]) by smtp.gmail.com with ESMTPSA id o5sm3727983wmg.25.2018.12.13.05.10.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 13 Dec 2018 05:10:07 -0800 (PST) Date: Thu, 13 Dec 2018 21:09:49 +0800 From: leo.yan@linaro.org To: Arnaldo Carvalho de Melo Subject: Re: [PATCH v3 6/8] perf cs-etm: Treat NO_SYNC element as trace discontinuity Message-ID: <20181213130949.GB17663@leoy-ThinkPad-X240s> References: <1544513908-16805-1-git-send-email-leo.yan@linaro.org> <1544513908-16805-7-git-send-email-leo.yan@linaro.org> <20181213123854.GE21027@kernel.org> <20181213124154.GF21027@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181213124154.GF21027@kernel.org> User-Agent: Mutt/1.10+31 (9cdd884) (2018-06-19) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181213_051020_712360_D0E24E26 X-CRM114-Status: GOOD ( 25.34 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mathieu Poirier , Alexander Shishkin , Coresight ML , linux-kernel@vger.kernel.org, Namhyung Kim , Robert Walker , Jiri Olsa , linux-arm-kernel@lists.infradead.org, Mike Leach Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Arnaldo, On Thu, Dec 13, 2018 at 09:41:54AM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, Dec 13, 2018 at 09:38:54AM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Tue, Dec 11, 2018 at 03:38:26PM +0800, Leo Yan escreveu: > > > CoreSight tracer driver might insert barrier packet between different > > > buffers, thus the decoder can spot the boundaries based on the barrier > > > packet; the decoder is possible to hit a barrier packet and emit a > > > NO_SYNC element, then the decoder will find a periodic synchronisation > > > point inside that next trace block that starts trace again but does not > > > have the TRACE_ON element as indicator - usually because this block of > > > trace has wrapped the buffer so we have lost the original point that > > > trace was enabled. > > > > > > In upper case, it results in the trace stream only inserts the > > > OCSD_GEN_TRC_ELEM_NO_SYNC element in the middle of tracing stream, but > > > we don't handle NO_SYNC element properly and at the end users miss to > > > see the info for trace discontinuity. > > > > > > "In upper case"? Maybe: > > > > In the former case it causes the insertion of a OCSD_GEN_TRC_ELEM_NO_SYNC > > in the middle of the the tracing stream, but as we were npt handling the > > NO_SYNC element properly which ends up making users miss the > > discontinuity indication"? > > > > Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON when > > > output from the decoder, but both of them indicate the trace data is > > > > can we remove the "but" and "of them" (redundant) above? > > > > > discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as trace > > a > > > discontinuity and generates CS_ETM_DISCONTINUITY packet for it, so > > > cs-etm can handle discontinuity for this case, finally it saves the last > > it (way too many "discontinuity") > > > trace data for previous trace block and restart samples for new block. > > I've tentatively done those changes (and a few more) in my local branch, > resulting in the wording below, plese let me know if you are ok with it: Very appreciate your helping. Please see some minor typos in below commit: > commit 148068b45fe2e93b19c06cfc1140ea12ca72eb59 > Author: Leo Yan > Date: Tue Dec 11 15:38:26 2018 +0800 > > perf cs-etm: Treat NO_SYNC element as trace discontinuity > > The CoreSight tracer driver might insert a barrier packets between packet > different buffers, thus the decoder can spot the boundaries based on the > barrier packet; it is possible for the decoder to hit a barrier packet > and emit a NO_SYNC element, then the decoder will find a periodic > synchronisation point inside that next trace block that starts the trace > again but does not have the TRACE_ON element as indicator - usually > because this trace block has wrapped the buffer so we have lost the > original point when the trace was enabled. > > In the first case it causes the insertion of a OCSD_GEN_TRC_ELEM_NO_SYNC former > in the middle of the the tracing stream, but as we were npt handling the not > NO_SYNC element properly which ends up making users miss the > discontinuity indication"? s/?/. Thanks a lot for helping. If you prefer me to resend the patch set, also let me know. > Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON when > output from the decoder, both indicate that the trace data is > discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as a trace > discontinuity and generates a CS_ETM_DISCONTINUITY packet for it, so > cs-etm can handle the discontinuity for this case, finally it saves the > last trace data for the previous trace block and restart samples for the > new block. > > Signed-off-by: Leo Yan > Reviewed-by: Mathieu Poirier > Cc: Alexander Shishkin > Cc: Jiri Olsa > Cc: Mike Leach > Cc: Namhyung Kim > Cc: Robert Walker > Cc: coresight ml > Cc: linux-arm-kernel@lists.infradead.org > Link: http://lkml.kernel.org/r/1544513908-16805-7-git-send-email-leo.yan@linaro.org > Signed-off-by: Arnaldo Carvalho de Melo > > diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > index 1039f364f4cc..bee026e76a4c 100644 > --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > @@ -410,7 +410,6 @@ static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer( > case OCSD_GEN_TRC_ELEM_UNKNOWN: > break; > case OCSD_GEN_TRC_ELEM_NO_SYNC: > - break; > case OCSD_GEN_TRC_ELEM_TRACE_ON: > resp = cs_etm_decoder__buffer_discontinuity(decoder, > trace_chan_id); > > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel