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f83d436aef
Increase the parallelism level for pwork clients to the workqueue defaults so that we can take advantage of computers with a lot of CPUs and a lot of hardware. On fast systems this will speed up quotacheck by a large factor, and the following posteof/cowblocks cleanup series will use the functionality presented in this patch to run garbage collection as quickly as possible. We do this by switching the pwork workqueue to unbounded, since the current user (quotacheck) runs lengthy scans for each work item and we don't care about dispatching the work on a warm cpu cache or anything like that. Also set WQ_SYSFS so that we can monitor where the wq is running. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com>
121 lines
3.2 KiB
C
121 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2019 Oracle. All Rights Reserved.
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* Author: Darrick J. Wong <darrick.wong@oracle.com>
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*/
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#include "xfs.h"
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#include "xfs_fs.h"
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#include "xfs_shared.h"
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#include "xfs_format.h"
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#include "xfs_log_format.h"
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#include "xfs_trans_resv.h"
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#include "xfs_mount.h"
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#include "xfs_trace.h"
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#include "xfs_sysctl.h"
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#include "xfs_pwork.h"
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#include <linux/nmi.h>
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/*
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* Parallel Work Queue
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* ===================
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*
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* Abstract away the details of running a large and "obviously" parallelizable
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* task across multiple CPUs. Callers initialize the pwork control object with
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* a desired level of parallelization and a work function. Next, they embed
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* struct xfs_pwork in whatever structure they use to pass work context to a
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* worker thread and queue that pwork. The work function will be passed the
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* pwork item when it is run (from process context) and any returned error will
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* be recorded in xfs_pwork_ctl.error. Work functions should check for errors
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* and abort if necessary; the non-zeroness of xfs_pwork_ctl.error does not
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* stop workqueue item processing.
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*
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* This is the rough equivalent of the xfsprogs workqueue code, though we can't
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* reuse that name here.
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*/
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/* Invoke our caller's function. */
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static void
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xfs_pwork_work(
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struct work_struct *work)
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{
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struct xfs_pwork *pwork;
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struct xfs_pwork_ctl *pctl;
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int error;
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pwork = container_of(work, struct xfs_pwork, work);
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pctl = pwork->pctl;
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error = pctl->work_fn(pctl->mp, pwork);
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if (error && !pctl->error)
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pctl->error = error;
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if (atomic_dec_and_test(&pctl->nr_work))
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wake_up(&pctl->poll_wait);
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}
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/*
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* Set up control data for parallel work. @work_fn is the function that will
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* be called. @tag will be written into the kernel threads. @nr_threads is
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* the level of parallelism desired, or 0 for no limit.
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*/
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int
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xfs_pwork_init(
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struct xfs_mount *mp,
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struct xfs_pwork_ctl *pctl,
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xfs_pwork_work_fn work_fn,
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const char *tag)
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{
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unsigned int nr_threads = 0;
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#ifdef DEBUG
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if (xfs_globals.pwork_threads >= 0)
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nr_threads = xfs_globals.pwork_threads;
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#endif
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trace_xfs_pwork_init(mp, nr_threads, current->pid);
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pctl->wq = alloc_workqueue("%s-%d",
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WQ_UNBOUND | WQ_SYSFS | WQ_FREEZABLE, nr_threads, tag,
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current->pid);
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if (!pctl->wq)
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return -ENOMEM;
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pctl->work_fn = work_fn;
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pctl->error = 0;
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pctl->mp = mp;
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atomic_set(&pctl->nr_work, 0);
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init_waitqueue_head(&pctl->poll_wait);
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return 0;
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}
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/* Queue some parallel work. */
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void
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xfs_pwork_queue(
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struct xfs_pwork_ctl *pctl,
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struct xfs_pwork *pwork)
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{
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INIT_WORK(&pwork->work, xfs_pwork_work);
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pwork->pctl = pctl;
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atomic_inc(&pctl->nr_work);
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queue_work(pctl->wq, &pwork->work);
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}
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/* Wait for the work to finish and tear down the control structure. */
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int
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xfs_pwork_destroy(
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struct xfs_pwork_ctl *pctl)
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{
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destroy_workqueue(pctl->wq);
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pctl->wq = NULL;
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return pctl->error;
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}
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/*
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* Wait for the work to finish by polling completion status and touch the soft
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* lockup watchdog. This is for callers such as mount which hold locks.
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*/
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void
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xfs_pwork_poll(
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struct xfs_pwork_ctl *pctl)
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{
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while (wait_event_timeout(pctl->poll_wait,
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atomic_read(&pctl->nr_work) == 0, HZ) == 0)
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touch_softlockup_watchdog();
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}
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