From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZr0JpreXblJra/HyNeCIzkn0XnldV3bLMup+E5Ocfm5zU/JoEg0lMzGl+aKXzEymvSnEIld ARC-Seal: i=1; a=rsa-sha256; t=1525360382; cv=none; d=google.com; s=arc-20160816; b=zk4ljCsLKTVj8JgHQnw5oMykvKkaHRJeBZ92BuvCQMT7DfCthQvucsAqBwYSW6iW0Z gB5SosOL+2IC2lJwlGzc+tXqhLtmq2hPyL8yWqJ/HWLq5Rxg4s5xm4PT6Xn1reoCoknn V6xWq+qH52bBBI5zbsuRhxm5JZSC86ofDJS6YMHATB8euilfFJqjbbg18r2FNIIz99do tYaWk02v3LCRMBj7i7YJGFqXqbxHcLo8l/WrelmPyKfy/BM77261+Vnz+V1Aj0hiXWgy I2HgLcoPz2D5ad0U2pFIjsSvtsWqAjL1mzuUx351z7Rc7WDDhsKgckB/zdWVvrLrhExh IK9Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:arc-authentication-results; bh=kFhlqmjAN8XThnq4kv75WoxmejmVQnN0zA/GJBOW98s=; b=uio8lTteLf3vgw82oCnPkeB1+8yx6JST2qKZucdop2bdHBxF2rZgbbwmoowCfZw0T3 mXBdgbIryGcrbiCj03tBAYRKeaWHOhzHdbFjR639rD7fXbvbOZJLyrm+WLNE4GVUCPFT uJ+8b1VMQOIqUSyWdwF6L3PbPE0wQjYmGCzWjrkg62qBHKbmsMdrTd1nXo/Aq94FIS8D Pi0Vxy7ytyXFANdfW+GifOVyMFa15pMHxj51r1D2vR4AaDsFSSAPhMFnNKOqLTq65anu AWIYj71dXVGRWwWJaJ6FKhT/qTHyJkbEtKSgNxnqSNYKZPjuOG0h7QlVYrMON5rmV3Gg 2xtA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of morten.rasmussen@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=morten.rasmussen@arm.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of morten.rasmussen@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=morten.rasmussen@arm.com Date: Thu, 3 May 2018 16:12:55 +0100 From: Morten Rasmussen To: Jeremy Linton Cc: linux-acpi@vger.kernel.org, Sudeep.Holla@arm.com, linux-arm-kernel@lists.infradead.org, Lorenzo.Pieralisi@arm.com, hanjun.guo@linaro.org, rjw@rjwysocki.net, Will.Deacon@arm.com, Catalin.Marinas@arm.com, gregkh@linuxfoundation.org, Mark.Rutland@arm.com, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, wangxiongfeng2@huawei.com, vkilari@codeaurora.org, ahs3@redhat.com, Dietmar.Eggemann@arm.com, palmer@sifive.com, lenb@kernel.org, john.garry@huawei.com, austinwc@codeaurora.org, tnowicki@caviumnetworks.com, jhugo@qti.qualcomm.com, timur@qti.qualcomm.com, ard.biesheuvel@linaro.org Subject: Re: [PATCH v8 13/13] arm64: topology: divorce MC scheduling domain from core_siblings Message-ID: <20180503151255.GB28409@work-enc> References: <20180425233121.13270-1-jeremy.linton@arm.com> <20180425233121.13270-14-jeremy.linton@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180425233121.13270-14-jeremy.linton@arm.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1598766330955487456?= X-GMAIL-MSGID: =?utf-8?q?1599456288836095881?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, Apr 25, 2018 at 06:31:21PM -0500, Jeremy Linton wrote: > Now that we have an accurate view of the physical topology > we need to represent it correctly to the scheduler. Generally MC > should equal the LLC in the system, but there are a number of > special cases that need to be dealt with. > > In the case of NUMA in socket, we need to assure that the sched > domain we build for the MC layer isn't larger than the DIE above it. > Similarly for LLC's that might exist in cross socket interconnect or > directory hardware we need to assure that MC is shrunk to the socket > or NUMA node. > > This patch builds a sibling mask for the LLC, and then picks the > smallest of LLC, socket siblings, or NUMA node siblings, which > gives us the behavior described above. This is ever so slightly > different than the similar alternative where we look for a cache > layer less than or equal to the socket/NUMA siblings. > > The logic to pick the MC layer affects all arm64 machines, but > only changes the behavior for DT/MPIDR systems if the NUMA domain > is smaller than the core siblings (generally set to the cluster). > Potentially this fixes a possible bug in DT systems, but really > it only affects ACPI systems where the core siblings is correctly > set to the socket siblings. Thus all currently available ACPI > systems should have MC equal to LLC, including the NUMA in socket > machines where the LLC is partitioned between the NUMA nodes. > > Signed-off-by: Jeremy Linton This patch looks good to me. Acked-by: Morten Rasmussen