From 40786717c88c2d4cb426cc2eb99ac50000e5a910 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 3 Jul 2019 07:33:26 -0700 Subject: [PATCH] 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/Makefile | 1 + fs/xfs/xfs_globals.c | 3 ++ fs/xfs/xfs_iwalk.c | 82 ++++++++++++++++++++++++++++++ fs/xfs/xfs_iwalk.h | 2 + fs/xfs/xfs_pwork.c | 117 +++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_pwork.h | 58 +++++++++++++++++++++ fs/xfs/xfs_qm.c | 2 +- fs/xfs/xfs_sysctl.h | 3 ++ fs/xfs/xfs_sysfs.c | 40 +++++++++++++++ fs/xfs/xfs_trace.h | 18 +++++++ 10 files changed, 325 insertions(+), 1 deletion(-) create mode 100644 fs/xfs/xfs_pwork.c create mode 100644 fs/xfs/xfs_pwork.h diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index e4dc99dcf5ee..b74a47169297 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -85,6 +85,7 @@ xfs-y += xfs_aops.o \ xfs_message.o \ xfs_mount.o \ xfs_mru_cache.o \ + xfs_pwork.o \ xfs_reflink.o \ xfs_stats.o \ xfs_super.o \ diff --git a/fs/xfs/xfs_globals.c b/fs/xfs/xfs_globals.c index 4e4a7a299ccb..fa55ab8b8d80 100644 --- a/fs/xfs/xfs_globals.c +++ b/fs/xfs/xfs_globals.c @@ -40,4 +40,7 @@ struct xfs_globals xfs_globals = { #else .bug_on_assert = false, /* assert failures WARN() */ #endif +#ifdef DEBUG + .pwork_threads = -1, /* automatic thread detection */ +#endif }; diff --git a/fs/xfs/xfs_iwalk.c b/fs/xfs/xfs_iwalk.c index a0903150d2d8..d610eefed409 100644 --- a/fs/xfs/xfs_iwalk.c +++ b/fs/xfs/xfs_iwalk.c @@ -20,6 +20,7 @@ #include "xfs_icache.h" #include "xfs_health.h" #include "xfs_trans.h" +#include "xfs_pwork.h" /* * Walking Inodes in the Filesystem @@ -45,6 +46,9 @@ */ struct xfs_iwalk_ag { + /* parallel work control data; will be null if single threaded */ + struct xfs_pwork pwork; + struct xfs_mount *mp; struct xfs_trans *tp; @@ -182,6 +186,9 @@ xfs_iwalk_ag_recs( trace_xfs_iwalk_ag_rec(mp, agno, irec); + if (xfs_pwork_want_abort(&iwag->pwork)) + return 0; + if (iwag->inobt_walk_fn) { error = iwag->inobt_walk_fn(mp, tp, agno, irec, iwag->data); @@ -193,6 +200,9 @@ xfs_iwalk_ag_recs( continue; for (j = 0; j < XFS_INODES_PER_CHUNK; j++) { + if (xfs_pwork_want_abort(&iwag->pwork)) + return 0; + /* Skip if this inode is free */ if (XFS_INOBT_MASK(j) & irec->ir_free) continue; @@ -387,6 +397,8 @@ xfs_iwalk_ag( struct xfs_inobt_rec_incore *irec; cond_resched(); + if (xfs_pwork_want_abort(&iwag->pwork)) + goto out; /* Fetch the inobt record. */ irec = &iwag->recs[iwag->nr_recs]; @@ -520,6 +532,7 @@ xfs_iwalk( .sz_recs = xfs_iwalk_prefetch(inode_records), .trim_start = 1, .skip_empty = 1, + .pwork = XFS_PWORK_SINGLE_THREADED, }; xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, startino); int error; @@ -541,6 +554,74 @@ xfs_iwalk( return error; } +/* Run per-thread iwalk work. */ +static int +xfs_iwalk_ag_work( + struct xfs_mount *mp, + struct xfs_pwork *pwork) +{ + struct xfs_iwalk_ag *iwag; + int error = 0; + + iwag = container_of(pwork, struct xfs_iwalk_ag, pwork); + if (xfs_pwork_want_abort(pwork)) + goto out; + + error = xfs_iwalk_alloc(iwag); + if (error) + goto out; + + error = xfs_iwalk_ag(iwag); + xfs_iwalk_free(iwag); +out: + kmem_free(iwag); + return error; +} + +/* + * Walk all the inodes in the filesystem using multiple threads to process each + * AG. + */ +int +xfs_iwalk_threaded( + struct xfs_mount *mp, + xfs_ino_t startino, + xfs_iwalk_fn iwalk_fn, + unsigned int inode_records, + void *data) +{ + struct xfs_pwork_ctl pctl; + xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, startino); + unsigned int nr_threads; + int error; + + ASSERT(agno < mp->m_sb.sb_agcount); + + nr_threads = xfs_pwork_guess_datadev_parallelism(mp); + error = xfs_pwork_init(mp, &pctl, xfs_iwalk_ag_work, "xfs_iwalk", + nr_threads); + if (error) + return error; + + for (; agno < mp->m_sb.sb_agcount; agno++) { + struct xfs_iwalk_ag *iwag; + + if (xfs_pwork_ctl_want_abort(&pctl)) + break; + + iwag = kmem_zalloc(sizeof(struct xfs_iwalk_ag), KM_SLEEP); + iwag->mp = mp; + iwag->iwalk_fn = iwalk_fn; + iwag->data = data; + iwag->startino = startino; + iwag->sz_recs = xfs_iwalk_prefetch(inode_records); + xfs_pwork_queue(&pctl, &iwag->pwork); + startino = XFS_AGINO_TO_INO(mp, agno + 1, 0); + } + + return xfs_pwork_destroy(&pctl); +} + /* * Allow callers to cache up to a page's worth of inobt records. This reflects * the existing inumbers prefetching behavior. Since the inobt walk does not @@ -601,6 +682,7 @@ xfs_inobt_walk( .data = data, .startino = startino, .sz_recs = xfs_inobt_walk_prefetch(inobt_records), + .pwork = XFS_PWORK_SINGLE_THREADED, }; xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, startino); int error; diff --git a/fs/xfs/xfs_iwalk.h b/fs/xfs/xfs_iwalk.h index 94fad060b3e9..22c31763a9b8 100644 --- a/fs/xfs/xfs_iwalk.h +++ b/fs/xfs/xfs_iwalk.h @@ -15,6 +15,8 @@ typedef int (*xfs_iwalk_fn)(struct xfs_mount *mp, struct xfs_trans *tp, int xfs_iwalk(struct xfs_mount *mp, struct xfs_trans *tp, xfs_ino_t startino, xfs_iwalk_fn iwalk_fn, unsigned int inode_records, void *data); +int xfs_iwalk_threaded(struct xfs_mount *mp, xfs_ino_t startino, + xfs_iwalk_fn iwalk_fn, unsigned int inode_records, void *data); /* Walk all inode btree records in the filesystem starting from @startino. */ typedef int (*xfs_inobt_walk_fn)(struct xfs_mount *mp, struct xfs_trans *tp, 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; +} diff --git a/fs/xfs/xfs_pwork.h b/fs/xfs/xfs_pwork.h new file mode 100644 index 000000000000..99a9d210d49e --- /dev/null +++ b/fs/xfs/xfs_pwork.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2019 Oracle. All Rights Reserved. + * Author: Darrick J. Wong + */ +#ifndef __XFS_PWORK_H__ +#define __XFS_PWORK_H__ + +struct xfs_pwork; +struct xfs_mount; + +typedef int (*xfs_pwork_work_fn)(struct xfs_mount *mp, struct xfs_pwork *pwork); + +/* + * Parallel work coordination structure. + */ +struct xfs_pwork_ctl { + struct workqueue_struct *wq; + struct xfs_mount *mp; + xfs_pwork_work_fn work_fn; + int error; +}; + +/* + * Embed this parallel work control item inside your own work structure, + * then queue work with it. + */ +struct xfs_pwork { + struct work_struct work; + struct xfs_pwork_ctl *pctl; +}; + +#define XFS_PWORK_SINGLE_THREADED { .pctl = NULL } + +/* Have we been told to abort? */ +static inline bool +xfs_pwork_ctl_want_abort( + struct xfs_pwork_ctl *pctl) +{ + return pctl && pctl->error; +} + +/* Have we been told to abort? */ +static inline bool +xfs_pwork_want_abort( + struct xfs_pwork *pwork) +{ + return xfs_pwork_ctl_want_abort(pwork->pctl); +} + +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); +void xfs_pwork_queue(struct xfs_pwork_ctl *pctl, struct xfs_pwork *pwork); +int xfs_pwork_destroy(struct xfs_pwork_ctl *pctl); +unsigned int xfs_pwork_guess_datadev_parallelism(struct xfs_mount *mp); + +#endif /* __XFS_PWORK_H__ */ diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c index 588e36fe43f2..fb7a41fdde7f 100644 --- a/fs/xfs/xfs_qm.c +++ b/fs/xfs/xfs_qm.c @@ -1300,7 +1300,7 @@ xfs_qm_quotacheck( flags |= XFS_PQUOTA_CHKD; } - error = xfs_iwalk(mp, NULL, 0, xfs_qm_dqusage_adjust, 0, NULL); + error = xfs_iwalk_threaded(mp, 0, xfs_qm_dqusage_adjust, 0, NULL); if (error) goto error_return; diff --git a/fs/xfs/xfs_sysctl.h b/fs/xfs/xfs_sysctl.h index ad7f9be13087..8abf4640f1d5 100644 --- a/fs/xfs/xfs_sysctl.h +++ b/fs/xfs/xfs_sysctl.h @@ -82,6 +82,9 @@ enum { extern xfs_param_t xfs_params; struct xfs_globals { +#ifdef DEBUG + int pwork_threads; /* parallel workqueue threads */ +#endif int log_recovery_delay; /* log recovery delay (secs) */ int mount_delay; /* mount setup delay (secs) */ bool bug_on_assert; /* BUG() the kernel on assert failure */ diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c index 688366d42cd8..ddd0bf7a4740 100644 --- a/fs/xfs/xfs_sysfs.c +++ b/fs/xfs/xfs_sysfs.c @@ -204,11 +204,51 @@ always_cow_show( } XFS_SYSFS_ATTR_RW(always_cow); +#ifdef DEBUG +/* + * Override how many threads the parallel work queue is allowed to create. + * This has to be a debug-only global (instead of an errortag) because one of + * the main users of parallel workqueues is mount time quotacheck. + */ +STATIC ssize_t +pwork_threads_store( + struct kobject *kobject, + const char *buf, + size_t count) +{ + int ret; + int val; + + ret = kstrtoint(buf, 0, &val); + if (ret) + return ret; + + if (val < -1 || val > num_possible_cpus()) + return -EINVAL; + + xfs_globals.pwork_threads = val; + + return count; +} + +STATIC ssize_t +pwork_threads_show( + struct kobject *kobject, + char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.pwork_threads); +} +XFS_SYSFS_ATTR_RW(pwork_threads); +#endif /* DEBUG */ + static struct attribute *xfs_dbg_attrs[] = { ATTR_LIST(bug_on_assert), ATTR_LIST(log_recovery_delay), ATTR_LIST(mount_delay), ATTR_LIST(always_cow), +#ifdef DEBUG + ATTR_LIST(pwork_threads), +#endif NULL, }; diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index e61d519961a1..8094b1920eef 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -3557,6 +3557,24 @@ TRACE_EVENT(xfs_iwalk_ag_rec, __entry->startino, __entry->freemask) ) +TRACE_EVENT(xfs_pwork_init, + TP_PROTO(struct xfs_mount *mp, unsigned int nr_threads, pid_t pid), + TP_ARGS(mp, nr_threads, pid), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(unsigned int, nr_threads) + __field(pid_t, pid) + ), + TP_fast_assign( + __entry->dev = mp->m_super->s_dev; + __entry->nr_threads = nr_threads; + __entry->pid = pid; + ), + TP_printk("dev %d:%d nr_threads %u pid %u", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->nr_threads, __entry->pid) +) + #endif /* _TRACE_XFS_H */ #undef TRACE_INCLUDE_PATH