From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5AA68472F81 for ; Tue, 6 Oct 2026 15:03:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791299014; cv=none; b=ER9hBLVfsxkzJ5nIbREmo+ZCv9ebnatvaLh6A7KiCdYPvTkrPsJ6YlWyRN5XyUAAJIFiSef+PbNyL7Hdo58g/nMxFlKgSw7wcOJja06/ncy1J7HzuSj924+PYPpPjfg69xFLzHGhxJPpJBJEQxEaLfQFkujDeHOOw/HrSTuld2k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791299014; c=relaxed/simple; bh=jgAIfCf3cv0gECmzUtBGEQL5+TPUrp8X/vwGcLE+2UY=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=m4NpSMwnz83YYGIeSnE5d547VX3Ezfgf9TVUiuIUDfI+AK74VSnNJfR7y9cAfchc0k1giYo16MK8rH0mrS6oRuSmt5Yyz8+48q5QzT7mVJEp6Ej3INYad4L2YnBujyuzS886BJO0Es9z2tOT7HwbSt14IFX2CDt9/Fjw2POIwJ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GU9ChsWo; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GU9ChsWo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFB491F0089B; Tue, 6 Oct 2026 15:03:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791299012; bh=RY4NdtXMcGdcmz6wCn6uOOks7MGNFa/Cn+Egq2u62Uk=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=GU9ChsWowDVdOOydt3tk2qMlOvCf86WpFYNrg0MlrbOHBerLwdSNHmesaZN1sYh++ WpLpO2qY06HnmYIv+9kaP9Jxunumo+Vbo35+PsCu3BkOpm3sUKwTsNH55nyp1zPHSv sklbOKYVBCPah68njgJa0OP51Cqpyyx2MmaQd1uCDtMmgKjiyFExWEqB8bJlmoE+uc PAfjcvikwK1OqT0DTebxvhSbmxGSXklRTSgYNzFXGm4Yefl2z8UXJ9EkDnIyMGt9uj PnTcjn4JGR6hiT91ZOsqok55es2go/GdhJ8101S7Y2P/5JIWJ3gTc3C33c+JRhAFf+ 4lEmoQBINH8ZQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH 8/8] perf test: Add false_sharing workload exhibiting cross-CPU false sharing Reply-To: sashiko-reviews@lists.linux.dev To: "Arnaldo Carvalho de Melo" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261006145729.3028247-9-acme@kernel.org> References: <20261006145729.3028247-1-acme@kernel.org> <20261006145729.3028247-9-acme@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 06 Oct 2026 15:03:32 +0000 Message-Id: <20261006150332.BFB491F0089B@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > From: Arnaldo Carvalho de Melo >=20 > Add a 'perf test -w false_sharing' workload that hammers one shared > struct from several CPUs, shaped as a TCP connection: a read-mostly > identity (five-tuple) shares a cacheline with per-packet rx counters > (the false-sharing line), a second line has packet-path private tx and > congestion control counters, and a third the connection config. >=20 > The packet path runs in the main thread and up to four lookup threads > sum the five-tuple and pull the config, reading one volatile shared > instance directly so the accesses are PC-relative and resolvable by the > data type profiler. >=20 > Data type profiling of the workload with cacheline info: >=20 > [ ... ] > 0.00% 0.01% struct folio +0x34 (_refcount.counter) > 0.00% 0.00% struct folio +0x18 (mapping) >=20 > Assisted-by: LLM > Signed-off-by: Arnaldo Carvalho de Melo Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261006145729.3028= 247-1-acme@kernel.org?part=3D8