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 36B6518EFD4 for ; Thu, 26 Sep 2024 22:49:15 +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=1727390956; cv=none; b=l3cphM9Pc9C3Gx0nYuAAjvqkB0APSjALxwsI5rfv2r7Dig/kOghgRwplIzyAh9I2nBfRiONs8WmfxXI3kLyQ1iPY8U92iuQtewcTDvMBKaxNekmgDJn6GoGl9BzlQO1zoF9dLNShbMg9529Eo/yFwL6jaSj4VWj6SwFyaUV+izU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727390956; c=relaxed/simple; bh=UVWqd8JCyJZfI34n8W5YWdpj7Ne7Q02mox/PTG8iVws=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=GWPC5FvYKEVgk9pK+6MCUYPewUPh/uOBkRccYevD2N6M8N/MyKCUX+tD0j+kqf6qIXxMoAfxywR50KA0lJM+5EIQPMUrNgzFmTM8KA7rgQvdpmGzF0gPVwTtb0rR+ssKXl+FM3TPHc+o4wlCawzBOcHrcq6GNXz4sr8abEZxXAI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a9O1E/e6; 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="a9O1E/e6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 896A3C4CEC5; Thu, 26 Sep 2024 22:49:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727390955; bh=UVWqd8JCyJZfI34n8W5YWdpj7Ne7Q02mox/PTG8iVws=; h=From:To:Cc:Subject:Date:From; b=a9O1E/e6vdfNhh6/L+Xm3iLWW5POV6AmVZNr1OnkPhjinxGzwHNHVSeOfSlVEzBNE GpmjJSCvRZNoLilGgXLk7nNj5+Rqma5wUB7mRq/VXEFRIFjWBLTv4xqDdh67+q3H7d /rVfozKGlM4B8DQVyFGPMHft4t/XszLYgvTgTTqBrXjUxb8yzT7le3tAt35NbXqXqU nfElEZPhjAPV8QoWtg7W0H7VaKuvnG40M8JHcb8bjOwNb6gAX8GZW3PAr+8mnEeBZJ CtGoq7rJgc/ko4GBmN4oDStE6DR6mm5y8ivrtH9JUIWYGxT1g/9vXV9y+ct0bHP2U5 kZYbrjh8prX4A== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Andrew Morton , Peter Zijlstra , Thomas Gleixner , Vlastimil Babka Subject: [PATCH 00/20] kthread: Introduce preferred affinity v4 Date: Fri, 27 Sep 2024 00:48:48 +0200 Message-ID: <20240926224910.11106-1-frederic@kernel.org> X-Mailer: git-send-email 2.46.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Affining kthreads follow either of 4 existing different patterns: 1) Per-CPU kthreads must stay affine to a single CPU and never execute relevant code on any other CPU. This is currently handled by smpboot code which takes care of CPU-hotplug operations. 2) Kthreads that _have_ to be affine to a specific set of CPUs and can't run anywhere else. The affinity is set through kthread_bind_mask() and the subsystem takes care by itself to handle CPU-hotplug operations. 3) Kthreads that _prefer_ to be affine to a specific NUMA node. 4) Similar to the previous point but kthreads have a _preferred_ affinity different than a node. It is set manually like any other task and CPU-hotplug is supposed to be handled by the relevant subsystem so that the task is properly reaffined whenever a given CPU from the preferred affinity comes up or down. Also care must be taken so that the preferred affinity doesn't cross housekeeping cpumask boundaries. Currently the preferred affinity patterns (3 and 4) have at least 4 identified users, with more or less success when it comes to handle CPU-hotplug operations and CPU isolation. This is a infrastructure proposal to handle this (after cleanups from 01 to 10). Changes since v3: _ Handle CPU down from scheduler fallback (new patch 11/20), suggested by Michal Hocko _ Simplify accordlingly 13/20 and 16/20 _ Add acks Frederic Weisbecker (20): arm/bL_switcher: Use kthread_run_on_cpu() x86/resctrl: Use kthread_run_on_cpu() firmware: stratix10-svc: Use kthread_run_on_cpu() scsi: bnx2fc: Use kthread_create_on_cpu() scsi: bnx2i: Use kthread_create_on_cpu() scsi: qedi: Use kthread_create_on_cpu() soc/qman: test: Use kthread_run_on_cpu() kallsyms: Use kthread_run_on_cpu() lib: test_objpool: Use kthread_run_on_cpu() net: pktgen: Use kthread_create_on_node() sched: Handle CPU isolation on last resort fallback rq selection kthread: Make sure kthread hasn't started while binding it kthread: Default affine kthread to its preferred NUMA node mm: Create/affine kcompactd to its preferred node mm: Create/affine kswapd to its preferred node kthread: Implement preferred affinity rcu: Use kthread preferred affinity for RCU boost kthread: Unify kthread_create_on_cpu() and kthread_create_worker_on_cpu() automatic format treewide: Introduce kthread_run_worker[_on_cpu]() rcu: Use kthread preferred affinity for RCU exp kworkers arch/arm/common/bL_switcher.c | 10 +- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 28 +-- arch/x86/kvm/i8254.c | 2 +- crypto/crypto_engine.c | 2 +- drivers/cpufreq/cppc_cpufreq.c | 2 +- drivers/firmware/stratix10-svc.c | 9 +- drivers/gpu/drm/drm_vblank_work.c | 2 +- .../drm/i915/gem/selftests/i915_gem_context.c | 2 +- drivers/gpu/drm/i915/gt/selftest_execlists.c | 2 +- drivers/gpu/drm/i915/gt/selftest_hangcheck.c | 2 +- drivers/gpu/drm/i915/gt/selftest_slpc.c | 2 +- drivers/gpu/drm/i915/selftests/i915_request.c | 8 +- drivers/gpu/drm/msm/disp/msm_disp_snapshot.c | 2 +- drivers/gpu/drm/msm/msm_atomic.c | 2 +- drivers/gpu/drm/msm/msm_gpu.c | 2 +- drivers/gpu/drm/msm/msm_kms.c | 2 +- .../platform/chips-media/wave5/wave5-vpu.c | 2 +- drivers/net/dsa/mv88e6xxx/chip.c | 2 +- drivers/net/ethernet/intel/ice/ice_dpll.c | 2 +- drivers/net/ethernet/intel/ice/ice_gnss.c | 2 +- drivers/net/ethernet/intel/ice/ice_ptp.c | 2 +- drivers/platform/chrome/cros_ec_spi.c | 2 +- drivers/ptp/ptp_clock.c | 2 +- drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 7 +- drivers/scsi/bnx2i/bnx2i_init.c | 7 +- drivers/scsi/qedi/qedi_main.c | 6 +- drivers/soc/fsl/qbman/qman_test_stash.c | 6 +- drivers/spi/spi.c | 2 +- drivers/usb/typec/tcpm/tcpm.c | 2 +- drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 +- drivers/watchdog/watchdog_dev.c | 2 +- fs/erofs/zdata.c | 2 +- include/linux/cpuhotplug.h | 1 + include/linux/kthread.h | 56 ++++- kernel/kallsyms_selftest.c | 4 +- kernel/kthread.c | 201 ++++++++++++++++-- kernel/rcu/tree.c | 94 ++------ kernel/rcu/tree_plugin.h | 11 +- kernel/sched/core.c | 17 +- kernel/sched/ext.c | 2 +- kernel/workqueue.c | 2 +- lib/test_objpool.c | 19 +- mm/compaction.c | 43 +--- mm/vmscan.c | 8 +- net/core/pktgen.c | 7 +- net/dsa/tag_ksz.c | 2 +- net/dsa/tag_ocelot_8021q.c | 2 +- net/dsa/tag_sja1105.c | 2 +- 48 files changed, 339 insertions(+), 261 deletions(-) -- 2.46.0