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 56F5C3264F6 for ; Wed, 19 Aug 2026 12:59:14 +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=1787144355; cv=none; b=miLUKU6wNcRHCacqgNl1FSI5rJKym4EAsbxAhvq7rZSJWSxk8a8AiplYvOKJ1f3nKsa1EnFUo8U+6esManSLlkHJMxIBPQ/nWyJD0mvefup7GeSukVaEJgTZBKbXtVyvIKBH1eKk+sEv8XeVw+WUeZWZ4Cqwj+4m3LWz69LbxGg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787144355; c=relaxed/simple; bh=9RytVU90FrQIyGmvH9eElAZ7WG4SgDD3l2WiwHz+A2U=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=FCXi+d+q4IiEDvgPzep6J1FRAlGFNcfii5pUkHI67Ngm/714tq9duWl26PF81TfGEfh1aSjBZ425BWMOyr1cseCxTEZrk2jUKyrwj+gnD/sejmsFGOgOxhNQFRLQbvvvVO0Xe660WjnAYfS35hHgyA5TGEtfJM7j+RcAF25HQLg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=T4cwUzwd; 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="T4cwUzwd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7CE41F000E9; Wed, 19 Aug 2026 12:59:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787144354; bh=owJlyF+0OauxR97+lwDmfrQk5NSmjRyt6tuh4JkSx24=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=T4cwUzwdfiFZ5gfn0WWjkd3eYZrQWG/oVSSZVfZctIAIub1ln2be59kHKhVcpjsRx K6pht5+Uge2dH/bJNAN1kmu8OftSDHSDLpI0+Qacwa75Ck9kZ5tYnwHK33NTffazAH WnhynJnTAu0Gl14V1Qp1XwFsw/i5XehewsWKQ/IumX8zNlEhQ/pzTUxbTZRRm+0qdY D9VqVZ3q7MlnC1aQZAnt42oNcEOovyqECSEUPIA6h8NhEggeSWBmZ59JyUKoYs2XHS W0pUNmv2U5J+N9VBDb6k7QFMBmmTOeCtL66fSlhlMFZ33VbvB2lv3PucDAWZytMvG/ /9CU/3q778TPw== From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 6/7] genirq: Adaptive Global Software Interrupt Moderation (GSIM). Reply-To: sashiko-reviews@lists.linux.dev To: "Luigi Rizzo" Cc: linux-pci@vger.kernel.org In-Reply-To: <20260819124341.4185621-7-lrizzo@google.com> References: <20260819124341.4185621-1-lrizzo@google.com> <20260819124341.4185621-7-lrizzo@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 19 Aug 2026 12:59:13 +0000 Message-Id: <20260819125913.D7CE41F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > GSIM helps keeping system load (as defined later) under control, but > the use of a fixed moderation delay causes unnecessary latency when the > system load is already low. >=20 > We focus on two types of system load related to interrupts: > - total device interrupt rates. Some platforms show severe I/O > performance degradation with more than 1-2 Mintr/s across the entire > system. This affects especially server-class hardware with hundreds of > interrupt sources (NIC or SSD queues from many physical or virtualized > devices). > - percentage of time spent in hardirq. This can become problematic in > presence of large numbers of interrupt sources hitting individual CPUs > (for instance, as a result of attempts to isolate application CPUs > from interrupt load). >=20 > [ ... ] > hardirq_percent (delay_us =3D 200, target_intr_rate=3D0, iodepth 128) > hardirq% 1 10 20 30 40 50 60 70 > KIOPS 13900 13800 13300 12100 10400 8600 7400 6500 >=20 > Signed-off-by: Luigi Rizzo Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260819124341.4185= 621-1-lrizzo@google.com?part=3D6