From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB83BC433E0 for ; Wed, 12 Aug 2020 12:54:57 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7242920829 for ; Wed, 12 Aug 2020 12:54:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="iZkHMjgR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7242920829 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=QuSzOgSv7w8kblsLYtdRNPA1r8P86K8ldp9Tr/BndKc=; b=iZkHMjgRWbYQYHPDL8Bpgt70v/ MJqMfcw97Xh73uqmwXJ66QqMdAux0gYfdEnFu0QgJp9IRe5AGpSqNtuKcn5T3L4ZS8QeIxAEUe2nP pHLIN/khtEqKV7aE/RHnlhjnae6W/TY74fVyxYe30N6NTZhZ6VI8qsJgjSt6e9xJIep/m897jQcmX 6ySNiSrD7oCnW/Oi1ig21XYXw4Y4upbNMyqBbn6+3ag0SBVvuPLcirdXf1ZxMf2hfJiBwBzfqscpm ULjLEY2E3GGY3Z7sx1vJ2+TOX/EQZ2TvfJFU2BWRUjQlub5/xAHzfboQxBmjFn8hBcZLXZrEllSAM bgxc7PQg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k5qFv-0003sc-Py; Wed, 12 Aug 2020 12:53:23 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k5qFo-0003oL-9R for linux-arm-kernel@lists.infradead.org; Wed, 12 Aug 2020 12:53:18 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AFEE331B; Wed, 12 Aug 2020 05:53:12 -0700 (PDT) Received: from e113632-lin.cambridge.arm.com (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7AA023F70D; Wed, 12 Aug 2020 05:53:11 -0700 (PDT) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 00/17] sched: Instrument sched domain flags Date: Wed, 12 Aug 2020 13:52:43 +0100 Message-Id: <20200812125300.11889-1-valentin.schneider@arm.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200812_085316_461468_5172FAF0 X-CRM114-Status: GOOD ( 17.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: vincent.guittot@linaro.org, Quentin Perret , peterz@infradead.org, morten.rasmussen@arm.com, mingo@kernel.org, dietmar.eggemann@arm.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, I've repeatedly stared at an SD flag and asked myself "how should that be set up in the domain hierarchy anyway?". I figured that if we formalize our flags zoology a bit, we could also do some runtime assertions on them - this is what this series is all about. Patches ======= The idea is to associate the flags with metaflags that describes how they should be set in a sched domain hierarchy ("if this SD has it, all its {parents, children} have it") or how they behave wrt degeneration - details are in the comments and commit logs. The good thing is that the debugging bits go away when CONFIG_SCHED_DEBUG isn't set. The bad thing is that this replaces SD_* flags definitions with some unsavoury macros. This is mainly because I wanted to avoid having to duplicate work between declaring the flags and declaring their metaflags. Conceptually they are pretty close to the macros used for SCHED_FEAT. o Patches 1-2 remove a derelict flag and align the arm scheduler topology with arm64's o Patches 3-8 instrument SD flags with metadata and add assertions o Patches 9-10 are additional topology cleanups o Patches 11-16 each add a new flag to SD_DEGENERATE_GROUPS_MASK o Patch 17 leverage the previous 6 patches to further factorize domain degeneration Revisions ========= v4 -> v5 -------- The final git diff between v4 and v5 isn't too big; there is no diff on the domain degeneration side of things, it has just been split up in more patches. o Shuffled the series around to facilitate bisection (Ingo) I kept the arm bits at the start because that was a bit simpler, and in the unlikely case that needs to be reverted it won't be too hard. o Split the degeneration mask tweak into individual commits per new flag (Ingo) o Collected Reviewed-by from Dietmar; since I shuffled the whole lot I didn't keep your Tested-by, sorry! o Turned the SD flags into an enum with automagic power of 2 assignment. I poked the dwarves and they assured me the SD flag values haven't changed. o [new patch] Made SD flag debug file output flag names v3 -> v4 -------- o Reordered the series to have fixes / cleanups first o Added SD_ASYM_CPUCAPACITY propagation (Quentin) o Made ARM revert back to the default sched topology (Dietmar) o Removed SD_SERIALIZE degeneration special case (Peter) o Made SD_NUMA and SD_SERIALIZE have SDF_NEEDS_GROUPS As discussed on v3, I thought this wasn't required, but thinking some more about it there can be cases where that changes the current behaviour. For instance, in the following wacky triangle: 0\ 30 | \ 20 | 2 | / 1/ 30 there are two unique distances thus two NUMA topology levels, however the first one for node 2 would have the same span as its child domain and thus should be degenerated. If we don't give SD_NUMA and SD_SERIALIZE SDF_NEEDS_GROUPS, this domain wouldn't be denegerated since its child *doesn't* have either SD_NUMA or SD_SERIALIZE (it's the first NUMA domain), and we'd have this weird NUMA domain lingering with a single group. v2 -> v3 -------- o Reworded comment for SD_OVERLAP (it's about the groups, not the domains) o Added more flags to the SD degeneration mask o Added generation of an SD flag mask for the degeneration functions (Peter) RFC -> v2 --------- o Rebased on top of tip/sched/core o Aligned wording of comments between flags o Rectified some flag descriptions (Morten) o Added removal of SD_SHARE_POWERDOMAIN (Morten) Valentin Schneider (17): ARM, sched/topology: Remove SD_SHARE_POWERDOMAIN ARM: Revert back to default scheduler topology. sched/topology: Split out SD_* flags declaration to its own file sched/topology: Define and assign sched_domain flag metadata sched/topology: Verify SD_* flags setup when sched_debug is on sched/debug: Output SD flag names rather than their values sched/topology: Introduce SD metaflag for flags needing > 1 groups sched/topology: Use prebuilt SD flag degeneration mask sched/topology: Remove SD_SERIALIZE degeneration special case sched/topology: Propagate SD_ASYM_CPUCAPACITY upwards sched/topology: Mark SD_PREFER_SIBLING as SDF_NEEDS_GROUPS sched/topology: Mark SD_BALANCE_WAKE as SDF_NEEDS_GROUPS sched/topology: Mark SD_SERIALIZE as SDF_NEEDS_GROUPS sched/topology: Mark SD_ASYM_PACKING as SDF_NEEDS_GROUPS sched/topology: Mark SD_OVERLAP as SDF_NEEDS_GROUPS sched/topology: Mark SD_NUMA as SDF_NEEDS_GROUPS sched/topology: Expand use of SD_DEGENERATE_GROUPS_MASK to flags not needing groups arch/arm/kernel/topology.c | 26 ------ include/linux/sched/sd_flags.h | 156 +++++++++++++++++++++++++++++++++ include/linux/sched/topology.h | 45 +++++++--- kernel/sched/debug.c | 53 ++++++++++- kernel/sched/topology.c | 54 ++++++------ 5 files changed, 265 insertions(+), 69 deletions(-) create mode 100644 include/linux/sched/sd_flags.h -- 2.27.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel