From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793941616; b=JHBvYNYATg/YLduFKh2Tx0nmAIhLh6WkkQj6CQRyarfperduxBDhs+XxLtmNonD/54RA d60jWU1/LZXYyFUb8IYrS1okqvbkAesYlnfJ4SCuJyg5icXTEMVhSfT+zKZr5ovtzLLZA ZDNJ9MR5iaTKbH5uGhKG2A3Y9gwZcLMM78hqToFDuAFAemfQxBPnA8/A78nftUl0b4q4U z19bP6APGCQtoEVzHj5x6dyHFC29/gGnY6KASGCpcETd9Vq3Bt3+g1h2cZa1jvJLBWuXF A4YS93ioc0Z4Q+JJzCZr34jy/cHzVbJp6Q+Ol6Ear1AtkpNQJKbB/rH7EpRNFUOCWBA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793941616; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=aOMsEvfHj9rMRLucaFcY3QEQu2DM7YKIhu7nrKbO8vM=; b=sbj/mp+Ra3MuKZp+WnogII4EI9UIfLiuHYRHgrcSsfor9GSWl3WixTd2Xs41D/3V4vYE Kr9jKa8uxsGK0dXSTSfxgV0dDggODddU3T4ircK8BI+AC8KHoCehoBppswC3X3SVoZxUx HNKDqL7GOvRy8ZZSM5q+2Pr56g2V/oYRW/Uf2OX0SMgx7Y1SPni0s6TKsBwj594j68J2y M5FDADTPp63FoAKTMdMbR+t9st5F1bfOBZmBUfXap1g5ugS+0pzKa3foUKBvDhWCUYhM2 nKpfmOBhXzZNBA2TnZUULanGFQw2vDXCkDT4LamKtV9/M0FgwP/EgIostwyKKkJgfQw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=a3R4Dy8S; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 53847606A31B for ; Fri, 6 Nov 2026 05:06:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=a3R4Dy8S Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8C9F1F0089F; Fri, 6 Nov 2026 05:06:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793941615; bh=aOMsEvfHj9rMRLucaFcY3QEQu2DM7YKIhu7nrKbO8vM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=a3R4Dy8Sr131r2Pc6V+LXcc7HQLN2daxoTad6avzigLDFEKzN/oxQvTu/rwuSFsSu 3JtLFj5XgfrPGDq7GkOz798/7hXaWBNU5yFcIirvn/ZuaJoB/KMQFQ5Ng8sZy5xKKu 1AgPFDiZgMEngWbVT82XuFSaocjp7TZEG2So7gDYedFLILHdj6WR/nig8BuBe80W64 E6W9y2GH2X6q2qeP/xriKzX1RrfUG4WfoEqPgPaI/RqKXgNIZfA/QlFSg/6kfBgM2V KUqjlWVI8Urq43fpOVi5w/gJ1KgpBNHXQ9Ea2CwF4DmctilKZXfnFUhcl71n0jpCzi uA/3Q1KB12OUA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v7 07/14] alpha/perf: implement ProfileMe sampling Reply-To: sashiko-reviews@lists.linux.dev To: "Matt Turner" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261105-alpha-profileme-v7-7-c474e892abb0@gmail.com> References: <20261105-alpha-profileme-v7-0-c474e892abb0@gmail.com> <20261105-alpha-profileme-v7-7-c474e892abb0@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 06 Nov 2026 05:06:55 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > The 21264 (EV67 and later) and 21364 have two performance counting modes, > and the driver only uses Aggregate mode. Its samples report the PC at > which the counter interrupt was taken, which lands a variable number of > instructions after the one that overflowed the counter. On an EV7 a > 16-instruction user loop shows up at only 4 PCs, anywhere from 15 > instructions before to 12 after the real one. >=20 > In ProfileMe mode, the instruction that overflows PCTR0 opens a window > during which PCTR1 counts, and when it closes PALcode delivers the > interrupt with that instruction's PC latched in PMPC. >=20 > Select ProfileMe with the new profileme config bit or with precise_ip, > since PMPC has no skid. PCTR_CTL[SL0] selects the mode for both > counters, so a ProfileMe event is scheduled alone and perf core > multiplexes it with other hardware events. precise_ip 3 is refused, as > [ ... ] > Suggested-by: Magnus Lindholm > Assisted-by: Claude:claude-opus-5-5 > Reviewed-by: Magnus Lindholm > Tested-by: Magnus Lindholm > Signed-off-by: Matt Turner Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261105-alpha-prof= ileme-v7-0-c474e892abb0@gmail.com?part=3D7