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 DF0F82EE608 for ; Mon, 25 Aug 2025 13:55:03 +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=1756130104; cv=none; b=s+W5uErzKgYYtFPa38j10AmwW9BwZqKUiS91B5av3EuqUyxYwUP0VmIqd+9s89ZC/dY4f7YlIkt4hfdY0JPBieyfEd8w4EvQddevUpGOvSIGrOnwYCPBg4CdmG1IeRt1kQBeL8FBpmXc1jzRPYGyqmlHfEU0CKkbiTca8sEDLAU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756130104; c=relaxed/simple; bh=cvEhUlh/at1MYhYP9O/AhyCcG9/rDmrBEzSWnFV4v7U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UCtCivAtaVJnjVtfw2Z3zQGp0r6mTxkkyeP44g45CQ3tR8PSaTyTfU67NRL7zW7FMa2sHtVkNwQMjA4SQH0OzJU0ccDcq2DZ4+8p5VHbDAMbDiLSQg1CutpqzWXZA6VYyckoWgir3TPBCMPIrR+og4RaUIrd3NzaHpPB65Bb0wQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=o8CINZ5J; 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="o8CINZ5J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DEC34C4CEED; Mon, 25 Aug 2025 13:55:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756130103; bh=cvEhUlh/at1MYhYP9O/AhyCcG9/rDmrBEzSWnFV4v7U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=o8CINZ5JC6+BcL7DOxhfO+G6hu3+Cqv/csP6zLOb6b3d9Sif+fbzZYtCw3ebaFWpH f4A/glB5wAT6+knnUndKosxALKyg67ufy97VhGFDRn7IirNKBMthfG/tRGwsjd+lsM Zb5csNR50Co29el2FLClbtJ9kNsdtngVtobMA3LF4qbbBqsfn5/VoSoptzN183jXIS h6Q0dvMy+5rlIvn7nggERm4sNSrwyWpiNgYs3jz2ULpqlt7ScZLyrcdCXnqmoKRGCb MJktIa70CcNKCc/WxfO2MaBz4zLj082c0vs0xvV9/Fy0RiNarsFDTQIvK8c+dEuBe9 YfvdOqe+WLu8g== Date: Mon, 25 Aug 2025 15:55:00 +0200 From: Frederic Weisbecker To: Marco Crivellari Cc: linux-kernel@vger.kernel.org, Tejun Heo , Lai Jiangshan , Thomas Gleixner , Sebastian Andrzej Siewior , Michal Hocko Subject: Re: [PATCH v2 3/4] Workqueue: WQ_PERCPU added to all the remaining users Message-ID: References: <20250825132906.1050437-1-marco.crivellari@suse.com> <20250825132906.1050437-4-marco.crivellari@suse.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250825132906.1050437-4-marco.crivellari@suse.com> Le Mon, Aug 25, 2025 at 03:29:05PM +0200, Marco Crivellari a écrit : > Currently if a user enqueue a work item using schedule_delayed_work() the > used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use > WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to > schedule_work() that is using system_wq and queue_work(), that makes use > again of WORK_CPU_UNBOUND. > This lack of consistentcy cannot be addressed without refactoring the API. > > alloc_workqueue() treats all queues as per-CPU by default, while unbound > workqueues must opt-in via WQ_UNBOUND. > > This default is suboptimal: most workloads benefit from unbound queues, > allowing the scheduler to place worker threads where they’re needed and > reducing noise when CPUs are isolated. > > This default is suboptimal: most workloads benefit from unbound queues, > allowing the scheduler to place worker threads where they’re needed and > reducing noise when CPUs are isolated. > > This patch adds a new WQ_PERCPU flag to explicitly request the use of > the per-CPU behavior. Both flags coexist for one release cycle to allow > callers to transition their calls. > > Once migration is complete, WQ_UNBOUND can be removed and unbound will > become the implicit default. > > With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), > any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND > must now use WQ_PERCPU. > > All existing users have been updated accordingly. > > Suggested-by: Tejun Heo > Signed-off-by: Marco Crivellari A similar per subsystem patch cut should be done here. > --- > block/bio-integrity-auto.c | 5 +++-- > block/bio.c | 3 ++- > block/blk-core.c | 3 ++- > block/blk-throttle.c | 3 ++- > block/blk-zoned.c | 3 ++- One for block. > crypto/cryptd.c | 3 ++- One for crypto API. > drivers/acpi/ec.c | 3 ++- > drivers/acpi/osl.c | 4 ++-- > drivers/acpi/thermal.c | 3 ++- > drivers/ata/libata-sff.c | 3 ++- > drivers/base/core.c | 2 +- > drivers/block/aoe/aoemain.c | 2 +- > drivers/block/rbd.c | 2 +- > drivers/block/rnbd/rnbd-clt.c | 2 +- > drivers/block/sunvdc.c | 2 +- > drivers/block/virtio_blk.c | 2 +- > drivers/bus/mhi/ep/main.c | 2 +- > drivers/char/tpm/tpm-dev-common.c | 3 ++- > drivers/char/xillybus/xillybus_core.c | 2 +- > drivers/char/xillybus/xillyusb.c | 4 ++-- > drivers/cpufreq/tegra194-cpufreq.c | 3 ++- > drivers/crypto/atmel-i2c.c | 2 +- > drivers/crypto/cavium/nitrox/nitrox_mbx.c | 2 +- > drivers/crypto/intel/qat/qat_common/adf_aer.c | 4 ++-- > drivers/crypto/intel/qat/qat_common/adf_isr.c | 3 ++- > .../crypto/intel/qat/qat_common/adf_sriov.c | 3 ++- > .../crypto/intel/qat/qat_common/adf_vf_isr.c | 3 ++- > drivers/firewire/core-transaction.c | 3 ++- > drivers/firewire/ohci.c | 3 ++- > drivers/gpu/drm/amd/amdkfd/kfd_process.c | 3 ++- > drivers/gpu/drm/bridge/analogix/anx7625.c | 3 ++- > .../drm/i915/display/intel_display_driver.c | 3 ++- > drivers/gpu/drm/i915/i915_driver.c | 3 ++- > .../gpu/drm/i915/selftests/i915_sw_fence.c | 2 +- > .../gpu/drm/i915/selftests/mock_gem_device.c | 2 +- > drivers/gpu/drm/nouveau/nouveau_drm.c | 2 +- > drivers/gpu/drm/nouveau/nouveau_sched.c | 3 ++- > drivers/gpu/drm/radeon/radeon_display.c | 3 ++- > drivers/gpu/drm/xe/xe_device.c | 4 ++-- > drivers/gpu/drm/xe/xe_ggtt.c | 2 +- > drivers/gpu/drm/xe/xe_hw_engine_group.c | 3 ++- > drivers/gpu/drm/xe/xe_sriov.c | 2 +- > drivers/greybus/operation.c | 2 +- > drivers/hid/hid-nintendo.c | 3 ++- > drivers/hv/mshv_eventfd.c | 2 +- > drivers/i3c/master.c | 2 +- > drivers/infiniband/core/cm.c | 2 +- > drivers/infiniband/core/device.c | 4 ++-- > drivers/infiniband/hw/hfi1/init.c | 3 +-- > drivers/infiniband/hw/hfi1/opfn.c | 3 +-- > drivers/infiniband/hw/mlx4/cm.c | 2 +- > drivers/infiniband/sw/rdmavt/cq.c | 3 ++- > drivers/infiniband/ulp/iser/iscsi_iser.c | 2 +- > drivers/infiniband/ulp/isert/ib_isert.c | 2 +- > drivers/infiniband/ulp/rtrs/rtrs-clt.c | 2 +- > drivers/infiniband/ulp/rtrs/rtrs-srv.c | 2 +- > drivers/input/mouse/psmouse-smbus.c | 2 +- > drivers/isdn/capi/kcapi.c | 2 +- > drivers/md/bcache/btree.c | 3 ++- > drivers/md/bcache/super.c | 10 ++++++---- > drivers/md/bcache/writeback.c | 2 +- > drivers/md/dm-bufio.c | 3 ++- > drivers/md/dm-cache-target.c | 3 ++- > drivers/md/dm-clone-target.c | 3 ++- > drivers/md/dm-crypt.c | 6 ++++-- > drivers/md/dm-delay.c | 4 +++- > drivers/md/dm-integrity.c | 15 ++++++++++----- > drivers/md/dm-kcopyd.c | 3 ++- > drivers/md/dm-log-userspace-base.c | 3 ++- > drivers/md/dm-mpath.c | 5 +++-- > drivers/md/dm-raid1.c | 5 +++-- > drivers/md/dm-snap-persistent.c | 3 ++- > drivers/md/dm-stripe.c | 2 +- > drivers/md/dm-verity-target.c | 4 +++- > drivers/md/dm-writecache.c | 3 ++- > drivers/md/dm.c | 3 ++- > drivers/md/md.c | 4 ++-- > drivers/media/pci/ddbridge/ddbridge-core.c | 2 +- > .../platform/mediatek/mdp3/mtk-mdp3-core.c | 6 ++++-- > drivers/message/fusion/mptbase.c | 7 +++++-- > drivers/mmc/core/block.c | 3 ++- > drivers/mmc/host/omap.c | 2 +- > drivers/net/can/spi/hi311x.c | 3 ++- > drivers/net/can/spi/mcp251x.c | 3 ++- > .../net/ethernet/cavium/liquidio/lio_core.c | 2 +- > .../net/ethernet/cavium/liquidio/lio_main.c | 8 +++++--- > .../ethernet/cavium/liquidio/lio_vf_main.c | 3 ++- > .../cavium/liquidio/request_manager.c | 2 +- > .../cavium/liquidio/response_manager.c | 3 ++- > .../net/ethernet/freescale/dpaa2/dpaa2-eth.c | 2 +- > .../hisilicon/hns3/hns3pf/hclge_main.c | 3 ++- > drivers/net/ethernet/intel/fm10k/fm10k_main.c | 2 +- > drivers/net/ethernet/intel/i40e/i40e_main.c | 2 +- > .../net/ethernet/marvell/octeontx2/af/cgx.c | 2 +- > .../marvell/octeontx2/af/mcs_rvu_if.c | 2 +- > .../ethernet/marvell/octeontx2/af/rvu_cgx.c | 2 +- > .../ethernet/marvell/octeontx2/af/rvu_rep.c | 2 +- > .../marvell/octeontx2/nic/cn10k_ipsec.c | 3 ++- > .../ethernet/marvell/prestera/prestera_main.c | 2 +- > .../ethernet/marvell/prestera/prestera_pci.c | 2 +- > drivers/net/ethernet/mellanox/mlxsw/core.c | 4 ++-- > drivers/net/ethernet/netronome/nfp/nfp_main.c | 2 +- > drivers/net/ethernet/qlogic/qed/qed_main.c | 3 ++- > drivers/net/ethernet/wiznet/w5100.c | 2 +- > drivers/net/fjes/fjes_main.c | 5 +++-- > drivers/net/wireguard/device.c | 6 ++++-- > drivers/net/wireless/ath/ath6kl/usb.c | 2 +- > .../net/wireless/marvell/libertas/if_sdio.c | 3 ++- > .../net/wireless/marvell/libertas/if_spi.c | 3 ++- > .../net/wireless/marvell/libertas_tf/main.c | 2 +- > drivers/net/wireless/quantenna/qtnfmac/core.c | 3 ++- > drivers/net/wireless/realtek/rtlwifi/base.c | 2 +- > drivers/net/wireless/realtek/rtw88/usb.c | 3 ++- > drivers/net/wireless/silabs/wfx/main.c | 2 +- > drivers/net/wireless/st/cw1200/bh.c | 4 ++-- > drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c | 3 ++- > drivers/net/wwan/wwan_hwsim.c | 2 +- > drivers/nvme/host/tcp.c | 2 ++ > drivers/nvme/target/core.c | 5 +++-- > drivers/nvme/target/fc.c | 6 +++--- > drivers/nvme/target/tcp.c | 2 +- > drivers/pci/endpoint/functions/pci-epf-mhi.c | 2 +- > drivers/pci/endpoint/functions/pci-epf-ntb.c | 5 +++-- > drivers/pci/endpoint/functions/pci-epf-test.c | 3 ++- > drivers/pci/endpoint/functions/pci-epf-vntb.c | 5 +++-- > drivers/pci/hotplug/pnv_php.c | 3 ++- > drivers/pci/hotplug/shpchp_core.c | 3 ++- > .../platform/surface/surface_acpi_notify.c | 2 +- > drivers/power/supply/ab8500_btemp.c | 3 ++- > drivers/power/supply/ipaq_micro_battery.c | 3 ++- > drivers/rapidio/rio.c | 2 +- > drivers/s390/char/tape_3590.c | 2 +- > drivers/scsi/be2iscsi/be_main.c | 3 ++- > drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 2 +- > drivers/scsi/device_handler/scsi_dh_alua.c | 2 +- > drivers/scsi/fcoe/fcoe.c | 2 +- > drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 3 ++- > drivers/scsi/lpfc/lpfc_init.c | 2 +- > drivers/scsi/pm8001/pm8001_init.c | 2 +- > drivers/scsi/qedf/qedf_main.c | 15 ++++++++++----- > drivers/scsi/qedi/qedi_main.c | 2 +- > drivers/scsi/qla2xxx/qla_os.c | 2 +- > drivers/scsi/qla2xxx/qla_target.c | 2 +- > drivers/scsi/qla2xxx/tcm_qla2xxx.c | 2 +- > drivers/scsi/qla4xxx/ql4_os.c | 3 ++- > drivers/scsi/scsi_transport_fc.c | 7 ++++--- > drivers/soc/fsl/qbman/qman.c | 2 +- > drivers/staging/greybus/sdio.c | 2 +- > drivers/target/target_core_transport.c | 4 ++-- > drivers/target/target_core_xcopy.c | 2 +- > drivers/target/tcm_fc/tfc_conf.c | 2 +- > drivers/usb/core/hub.c | 2 +- > drivers/usb/gadget/function/f_hid.c | 3 +-- > drivers/usb/storage/uas.c | 2 +- > drivers/usb/typec/anx7411.c | 3 +-- > drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++- > drivers/virt/acrn/irqfd.c | 3 ++- > drivers/virtio/virtio_balloon.c | 3 ++- > drivers/xen/privcmd.c | 3 ++- One for drivers. > include/linux/workqueue.h | 4 ++-- One for workqueue. > kernel/bpf/cgroup.c | 3 ++- One for BPF. > kernel/cgroup/cgroup-v1.c | 2 +- > kernel/cgroup/cgroup.c | 2 +- One for cgroup. > kernel/padata.c | 5 +++-- One for padata. > kernel/power/main.c | 2 +- One for power. > kernel/rcu/tree.c | 4 ++-- One for RCU. > kernel/workqueue.c | 19 ++++++++++--------- Join the workqueue change above. > virt/kvm/eventfd.c | 2 +- And one for KVM. Thanks. -- Frederic Weisbecker SUSE Labs