From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A0ECF1EB39 for ; Mon, 1 Jul 2024 08:02:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719820922; cv=none; b=AEPvxSO8kfXt0z00Qx6O1j7NwpbbGZnxLUc4Bk20QrgucibYSMk6WVzANKrQraUdU9fxYqvO4+fdQ04hBeKELHPli1gLJt13ZxrwKj3AflDmFYXcdooJH6voIkbgAR3HscK3i4Nr0aP/8ZZjQVsu15jXQQUM4J4wJTeY84a5hJE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719820922; c=relaxed/simple; bh=RNR6K2TOb1Ga1tcDvDTlnAeZP4UvL2eIARu705tjdf4=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=Xb4pnzmzETDQR3mk2AdmxfpdXDumB+gUOldRmEK5wTZylbNCZDXjze05au7ZlNV5AEfvVKzT93/EhQCnzo+a9v1b+uLS4ger0s90ap1kILu3QGLmkfv5AjwG9xwBwhmbebtoTtjfEmIJupHf/kRMUlaEi4jT9pvzKidhpW4M4R4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mnrOLyib; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mnrOLyib" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40C15C116B1; Mon, 1 Jul 2024 08:02:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719820922; bh=RNR6K2TOb1Ga1tcDvDTlnAeZP4UvL2eIARu705tjdf4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mnrOLyibTtnCEosmDKMhOnpW+NDSK/wuJlIx3L50kNzvo4gdZS8zfiyh2XCebp+YU FaDNLZJ8xQh63rB+wBt81f9xGgOCerSyYYgZr0gS1uA8SOBjJw19ibSOrys5bpItPp XjpcIFjzsXdYYqtedz3SgYmdm9gSjZuQyFNOl1ZyaZRKtKopdcsfjjjWg66ebJ/bdV hbEQiCKPW9HYPFXjaMvqzrsuBhEKiyS0JMJmK+/RB2y3V30HpsSDXRrIQGK0TZj9IO l4mCBDIoOvyBGjRCkFtbxQlpRr/f9Dad7ermqYEfzohXI2kMwlPuoSBzpqXZN9iZ8T 8JTitQkjwzU3A== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1sOBz5-008hlF-Ur; Mon, 01 Jul 2024 09:02:00 +0100 Date: Mon, 01 Jul 2024 09:01:59 +0100 Message-ID: <86a5j1ilqg.wl-maz@kernel.org> From: Marc Zyngier To: Nianyao Tang Cc: , , , , Subject: Re: [RESPIN PATCH] irqchip/gic-v4.1: Use local 4_1 ITS to generate VSGI In-Reply-To: <20240701062042.4128863-1-tangnianyao@huawei.com> References: <20240701062042.4128863-1-tangnianyao@huawei.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.2 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: tangnianyao@huawei.com, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, guoyang2@huawei.com, wangwudi@hisilicon.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Please don't use "RESPIN" as a subject tag. This means nothing, and confuses the tooling such as b4, which expects a version number. If the code has changed in any way, increment the version number. This really should have been a v2. On Mon, 01 Jul 2024 07:20:42 +0100, Nianyao Tang wrote: > > On multi-node GICv4.1 system, VSGI senders always use one certain 4_1 ITS, > because find_4_1_its return the first its_node in list, regardless of > which node the VSGI sender is on. This brings guest vsgi performance drop > when VM is not deployed on the same node as this returned ITS. s/deployed/running/ > > On a 2-socket environment, each with one ITS and 32 cpu, GICv4.1 enabled, > 4U8G guest, 4 vcpu is deployed on same socket. s/deployed/running/ > When VM on socket0, kvm-unit-tests ipi_hw result is 850ns. > When VM on socket1, it is 750ns. The reason is VSGI sender always > use lasted reported ITS(that on socket1) to inject VSGI. The access s/lasted/the last/ > from cpu to other-socket ITS will cost 100ns more compared to cpu to > local ITS. > > To use local ITS, we can get 12% reduction in IPI latency. s/To use/By using a/ > > The patch modify find_4_1_its to firstly return per-cpu local_4_1_its, Drop "the patch". s/firstly/first/ > which is init when inherit the VPE table from the ITS on secondary CPUs. or from another CPU. > If fail to find local 4_1 ITS, return any 4_1 ITS like before. > > Signed-off-by: Nianyao Tang > Reviewed-by: Marc Zyngier No. I never gave this tag. You can (and probably should) add a "Suggested-by:" tag, but not a "Reviewed-by:", until I explicitly reply to the patch with that tag. Please resend it as a v3 with all of the above fixed. Thanks, M. -- Without deviation from the norm, progress is not possible.