mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 00:04:15 +08:00
3e5a428b26
Create a pwork destroy function that uses polling instead of uninterruptible sleep to wait for work items to finish so that we can touch the softlockup watchdog. IOWs, gross hack. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
137 lines
3.5 KiB
C
137 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (C) 2019 Oracle. All Rights Reserved.
|
|
* Author: Darrick J. Wong <darrick.wong@oracle.com>
|
|
*/
|
|
#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"
|
|
#include <linux/nmi.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;
|
|
if (atomic_dec_and_test(&pctl->nr_work))
|
|
wake_up(&pctl->poll_wait);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
atomic_set(&pctl->nr_work, 0);
|
|
init_waitqueue_head(&pctl->poll_wait);
|
|
|
|
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;
|
|
atomic_inc(&pctl->nr_work);
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Wait for the work to finish by polling completion status and touch the soft
|
|
* lockup watchdog. This is for callers such as mount which hold locks.
|
|
*/
|
|
void
|
|
xfs_pwork_poll(
|
|
struct xfs_pwork_ctl *pctl)
|
|
{
|
|
while (wait_event_timeout(pctl->poll_wait,
|
|
atomic_read(&pctl->nr_work) == 0, HZ) == 0)
|
|
touch_softlockup_watchdog();
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|