From 40786717c88c2d4cb426cc2eb99ac50000e5a910 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 3 Jul 2019 07:33:26 -0700 Subject: xfs: multithreaded iwalk implementation Create a parallel iwalk implementation and switch quotacheck to use it. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster --- fs/xfs/xfs_pwork.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 fs/xfs/xfs_pwork.c (limited to 'fs/xfs/xfs_pwork.c') diff --git a/fs/xfs/xfs_pwork.c b/fs/xfs/xfs_pwork.c new file mode 100644 index 000000000000..752c897741e0 --- /dev/null +++ b/fs/xfs/xfs_pwork.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2019 Oracle. All Rights Reserved. + * Author: Darrick J. Wong + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_trace.h" +#include "xfs_sysctl.h" +#include "xfs_pwork.h" + +/* + * Parallel Work Queue + * =================== + * + * Abstract away the details of running a large and "obviously" parallelizable + * task across multiple CPUs. Callers initialize the pwork control object with + * a desired level of parallelization and a work function. Next, they embed + * struct xfs_pwork in whatever structure they use to pass work context to a + * worker thread and queue that pwork. The work function will be passed the + * pwork item when it is run (from process context) and any returned error will + * be recorded in xfs_pwork_ctl.error. Work functions should check for errors + * and abort if necessary; the non-zeroness of xfs_pwork_ctl.error does not + * stop workqueue item processing. + * + * This is the rough equivalent of the xfsprogs workqueue code, though we can't + * reuse that name here. + */ + +/* Invoke our caller's function. */ +static void +xfs_pwork_work( + struct work_struct *work) +{ + struct xfs_pwork *pwork; + struct xfs_pwork_ctl *pctl; + int error; + + pwork = container_of(work, struct xfs_pwork, work); + pctl = pwork->pctl; + error = pctl->work_fn(pctl->mp, pwork); + if (error && !pctl->error) + pctl->error = error; +} + +/* + * Set up control data for parallel work. @work_fn is the function that will + * be called. @tag will be written into the kernel threads. @nr_threads is + * the level of parallelism desired, or 0 for no limit. + */ +int +xfs_pwork_init( + struct xfs_mount *mp, + struct xfs_pwork_ctl *pctl, + xfs_pwork_work_fn work_fn, + const char *tag, + unsigned int nr_threads) +{ +#ifdef DEBUG + if (xfs_globals.pwork_threads >= 0) + nr_threads = xfs_globals.pwork_threads; +#endif + trace_xfs_pwork_init(mp, nr_threads, current->pid); + + pctl->wq = alloc_workqueue("%s-%d", WQ_FREEZABLE, nr_threads, tag, + current->pid); + if (!pctl->wq) + return -ENOMEM; + pctl->work_fn = work_fn; + pctl->error = 0; + pctl->mp = mp; + + return 0; +} + +/* Queue some parallel work. */ +void +xfs_pwork_queue( + struct xfs_pwork_ctl *pctl, + struct xfs_pwork *pwork) +{ + INIT_WORK(&pwork->work, xfs_pwork_work); + pwork->pctl = pctl; + queue_work(pctl->wq, &pwork->work); +} + +/* Wait for the work to finish and tear down the control structure. */ +int +xfs_pwork_destroy( + struct xfs_pwork_ctl *pctl) +{ + destroy_workqueue(pctl->wq); + pctl->wq = NULL; + return pctl->error; +} + +/* + * Return the amount of parallelism that the data device can handle, or 0 for + * no limit. + */ +unsigned int +xfs_pwork_guess_datadev_parallelism( + struct xfs_mount *mp) +{ + struct xfs_buftarg *btp = mp->m_ddev_targp; + + /* + * For now we'll go with the most conservative setting possible, + * which is two threads for an SSD and 1 thread everywhere else. + */ + return blk_queue_nonrot(btp->bt_bdev->bd_queue) ? 2 : 1; +} -- cgit v1.2.3