From d0f40998dcf71051d8ff8632b2c399f18475716a Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 11 Jan 2018 15:06:40 +1100 Subject: [PATCH] staging: lustre: libcfs: remove workitem code. There are now no users. workqueues are doing the job that this used to do. Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- .../staging/lustre/include/linux/libcfs/libcfs.h | 1 - .../lustre/include/linux/libcfs/libcfs_workitem.h | 104 ----- drivers/staging/lustre/lnet/libcfs/Makefile | 2 +- drivers/staging/lustre/lnet/libcfs/module.c | 11 +- drivers/staging/lustre/lnet/libcfs/workitem.c | 466 --------------------- 5 files changed, 2 insertions(+), 582 deletions(-) delete mode 100644 drivers/staging/lustre/include/linux/libcfs/libcfs_workitem.h delete mode 100644 drivers/staging/lustre/lnet/libcfs/workitem.c diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs.h b/drivers/staging/lustre/include/linux/libcfs/libcfs.h index 5bd7bee..ca3472c 100644 --- a/drivers/staging/lustre/include/linux/libcfs/libcfs.h +++ b/drivers/staging/lustre/include/linux/libcfs/libcfs.h @@ -45,7 +45,6 @@ #include #include #include -#include #include #include #include diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs_workitem.h b/drivers/staging/lustre/include/linux/libcfs/libcfs_workitem.h deleted file mode 100644 index ddaca33..0000000 --- a/drivers/staging/lustre/include/linux/libcfs/libcfs_workitem.h +++ /dev/null @@ -1,104 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * GPL HEADER START - * - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 only, - * as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License version 2 for more details (a copy is included - * in the LICENSE file that accompanied this code). - * - * You should have received a copy of the GNU General Public License - * version 2 along with this program; If not, see - * http://www.gnu.org/licenses/gpl-2.0.html - * - * GPL HEADER END - */ -/* - * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. - * Use is subject to license terms. - * - * Copyright (c) 2012, Intel Corporation. - */ -/* - * This file is part of Lustre, http://www.lustre.org/ - * Lustre is a trademark of Sun Microsystems, Inc. - * - * libcfs/include/libcfs/libcfs_workitem.h - * - * Author: Isaac Huang - * Liang Zhen - * - * A workitems is deferred work with these semantics: - * - a workitem always runs in thread context. - * - a workitem can be concurrent with other workitems but is strictly - * serialized with respect to itself. - * - no CPU affinity, a workitem does not necessarily run on the same CPU - * that schedules it. However, this might change in the future. - * - if a workitem is scheduled again before it has a chance to run, it - * runs only once. - * - if a workitem is scheduled while it runs, it runs again after it - * completes; this ensures that events occurring while other events are - * being processed receive due attention. This behavior also allows a - * workitem to reschedule itself. - * - * Usage notes: - * - a workitem can sleep but it should be aware of how that sleep might - * affect others. - * - a workitem runs inside a kernel thread so there's no user space to access. - * - do not use a workitem if the scheduling latency can't be tolerated. - * - * When wi_action returns non-zero, it means the workitem has either been - * freed or reused and workitem scheduler won't touch it any more. - */ - -#ifndef __LIBCFS_WORKITEM_H__ -#define __LIBCFS_WORKITEM_H__ - -struct cfs_wi_sched; - -void cfs_wi_sched_destroy(struct cfs_wi_sched *sched); -int cfs_wi_sched_create(char *name, struct cfs_cpt_table *cptab, int cpt, - int nthrs, struct cfs_wi_sched **sched_pp); - -struct cfs_workitem; - -typedef int (*cfs_wi_action_t) (struct cfs_workitem *); -struct cfs_workitem { - /** chain on runq or rerunq */ - struct list_head wi_list; - /** working function */ - cfs_wi_action_t wi_action; - /** in running */ - unsigned short wi_running:1; - /** scheduled */ - unsigned short wi_scheduled:1; -}; - -static inline void -cfs_wi_init(struct cfs_workitem *wi, cfs_wi_action_t action) -{ - INIT_LIST_HEAD(&wi->wi_list); - - wi->wi_running = 0; - wi->wi_scheduled = 0; - wi->wi_action = action; -} - -void cfs_wi_schedule(struct cfs_wi_sched *sched, struct cfs_workitem *wi); -int cfs_wi_deschedule(struct cfs_wi_sched *sched, struct cfs_workitem *wi); -void cfs_wi_exit(struct cfs_wi_sched *sched, struct cfs_workitem *wi); - -int cfs_wi_startup(void); -void cfs_wi_shutdown(void); - -/** # workitem scheduler loops before reschedule */ -#define CFS_WI_RESCHED 128 - -#endif /* __LIBCFS_WORKITEM_H__ */ diff --git a/drivers/staging/lustre/lnet/libcfs/Makefile b/drivers/staging/lustre/lnet/libcfs/Makefile index db5b36c..730f2c6 100644 --- a/drivers/staging/lustre/lnet/libcfs/Makefile +++ b/drivers/staging/lustre/lnet/libcfs/Makefile @@ -15,7 +15,7 @@ libcfs-linux-objs += linux-mem.o libcfs-linux-objs := $(addprefix linux/,$(libcfs-linux-objs)) libcfs-all-objs := debug.o fail.o module.o tracefile.o \ - libcfs_string.o hash.o workitem.o \ + libcfs_string.o hash.o \ libcfs_cpu.o libcfs_mem.o libcfs_lock.o libcfs-objs := $(libcfs-linux-objs) $(libcfs-all-objs) diff --git a/drivers/staging/lustre/lnet/libcfs/module.c b/drivers/staging/lustre/lnet/libcfs/module.c index 555f476..a03f924 100644 --- a/drivers/staging/lustre/lnet/libcfs/module.c +++ b/drivers/staging/lustre/lnet/libcfs/module.c @@ -547,12 +547,6 @@ static int libcfs_init(void) goto cleanup_cpu; } - rc = cfs_wi_startup(); - if (rc) { - CERROR("initialize workitem: error %d\n", rc); - goto cleanup_deregister; - } - cfs_rehash_wq = alloc_workqueue("cfs_rh", WQ_SYSFS, 4); if (!cfs_rehash_wq) { CERROR("Failed to start rehash workqueue.\n"); @@ -563,15 +557,13 @@ static int libcfs_init(void) rc = cfs_crypto_register(); if (rc) { CERROR("cfs_crypto_register: error %d\n", rc); - goto cleanup_wi; + goto cleanup_deregister; } lustre_insert_debugfs(lnet_table, lnet_debugfs_symlinks); CDEBUG(D_OTHER, "portals setup OK\n"); return 0; - cleanup_wi: - cfs_wi_shutdown(); cleanup_deregister: misc_deregister(&libcfs_dev); cleanup_cpu: @@ -593,7 +585,6 @@ static void libcfs_exit(void) } cfs_crypto_unregister(); - cfs_wi_shutdown(); misc_deregister(&libcfs_dev); diff --git a/drivers/staging/lustre/lnet/libcfs/workitem.c b/drivers/staging/lustre/lnet/libcfs/workitem.c deleted file mode 100644 index 74a9595..0000000 --- a/drivers/staging/lustre/lnet/libcfs/workitem.c +++ /dev/null @@ -1,466 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * GPL HEADER START - * - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 only, - * as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License version 2 for more details (a copy is included - * in the LICENSE file that accompanied this code). - * - * You should have received a copy of the GNU General Public License - * version 2 along with this program; If not, see - * http://www.gnu.org/licenses/gpl-2.0.html - * - * GPL HEADER END - */ -/* - * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved. - * Use is subject to license terms. - * - * Copyright (c) 2011, 2012, Intel Corporation. - */ -/* - * This file is part of Lustre, http://www.lustre.org/ - * Lustre is a trademark of Sun Microsystems, Inc. - * - * libcfs/libcfs/workitem.c - * - * Author: Isaac Huang - * Liang Zhen - */ - -#define DEBUG_SUBSYSTEM S_LNET - -#include - -#define CFS_WS_NAME_LEN 16 - -struct cfs_wi_sched { - /* chain on global list */ - struct list_head ws_list; - /** serialised workitems */ - spinlock_t ws_lock; - /** where schedulers sleep */ - wait_queue_head_t ws_waitq; - /** concurrent workitems */ - struct list_head ws_runq; - /** - * rescheduled running-workitems, a workitem can be rescheduled - * while running in wi_action(), but we don't to execute it again - * unless it returns from wi_action(), so we put it on ws_rerunq - * while rescheduling, and move it to runq after it returns - * from wi_action() - */ - struct list_head ws_rerunq; - /** CPT-table for this scheduler */ - struct cfs_cpt_table *ws_cptab; - /** CPT id for affinity */ - int ws_cpt; - /** number of scheduled workitems */ - int ws_nscheduled; - /** started scheduler thread, protected by cfs_wi_data::wi_glock */ - unsigned int ws_nthreads:30; - /** shutting down, protected by cfs_wi_data::wi_glock */ - unsigned int ws_stopping:1; - /** serialize starting thread, protected by cfs_wi_data::wi_glock */ - unsigned int ws_starting:1; - /** scheduler name */ - char ws_name[CFS_WS_NAME_LEN]; -}; - -static struct cfs_workitem_data { - /** serialize */ - spinlock_t wi_glock; - /** list of all schedulers */ - struct list_head wi_scheds; - /** WI module is initialized */ - int wi_init; - /** shutting down the whole WI module */ - int wi_stopping; -} cfs_wi_data; - -static inline int -cfs_wi_sched_cansleep(struct cfs_wi_sched *sched) -{ - spin_lock(&sched->ws_lock); - if (sched->ws_stopping) { - spin_unlock(&sched->ws_lock); - return 0; - } - - if (!list_empty(&sched->ws_runq)) { - spin_unlock(&sched->ws_lock); - return 0; - } - spin_unlock(&sched->ws_lock); - return 1; -} - -/* XXX: - * 0. it only works when called from wi->wi_action. - * 1. when it returns no one shall try to schedule the workitem. - */ -void -cfs_wi_exit(struct cfs_wi_sched *sched, struct cfs_workitem *wi) -{ - LASSERT(!in_interrupt()); /* because we use plain spinlock */ - LASSERT(!sched->ws_stopping); - - spin_lock(&sched->ws_lock); - - LASSERT(wi->wi_running); - if (wi->wi_scheduled) { /* cancel pending schedules */ - LASSERT(!list_empty(&wi->wi_list)); - list_del_init(&wi->wi_list); - - LASSERT(sched->ws_nscheduled > 0); - sched->ws_nscheduled--; - } - - LASSERT(list_empty(&wi->wi_list)); - - wi->wi_scheduled = 1; /* LBUG future schedule attempts */ - spin_unlock(&sched->ws_lock); -} -EXPORT_SYMBOL(cfs_wi_exit); - -/** - * cancel schedule request of workitem \a wi - */ -int -cfs_wi_deschedule(struct cfs_wi_sched *sched, struct cfs_workitem *wi) -{ - int rc; - - LASSERT(!in_interrupt()); /* because we use plain spinlock */ - LASSERT(!sched->ws_stopping); - - /* - * return 0 if it's running already, otherwise return 1, which - * means the workitem will not be scheduled and will not have - * any race with wi_action. - */ - spin_lock(&sched->ws_lock); - - rc = !(wi->wi_running); - - if (wi->wi_scheduled) { /* cancel pending schedules */ - LASSERT(!list_empty(&wi->wi_list)); - list_del_init(&wi->wi_list); - - LASSERT(sched->ws_nscheduled > 0); - sched->ws_nscheduled--; - - wi->wi_scheduled = 0; - } - - LASSERT(list_empty(&wi->wi_list)); - - spin_unlock(&sched->ws_lock); - return rc; -} -EXPORT_SYMBOL(cfs_wi_deschedule); - -/* - * Workitem scheduled with (serial == 1) is strictly serialised not only with - * itself, but also with others scheduled this way. - * - * Now there's only one static serialised queue, but in the future more might - * be added, and even dynamic creation of serialised queues might be supported. - */ -void -cfs_wi_schedule(struct cfs_wi_sched *sched, struct cfs_workitem *wi) -{ - LASSERT(!in_interrupt()); /* because we use plain spinlock */ - LASSERT(!sched->ws_stopping); - - spin_lock(&sched->ws_lock); - - if (!wi->wi_scheduled) { - LASSERT(list_empty(&wi->wi_list)); - - wi->wi_scheduled = 1; - sched->ws_nscheduled++; - if (!wi->wi_running) { - list_add_tail(&wi->wi_list, &sched->ws_runq); - wake_up(&sched->ws_waitq); - } else { - list_add(&wi->wi_list, &sched->ws_rerunq); - } - } - - LASSERT(!list_empty(&wi->wi_list)); - spin_unlock(&sched->ws_lock); -} -EXPORT_SYMBOL(cfs_wi_schedule); - -static int cfs_wi_scheduler(void *arg) -{ - struct cfs_wi_sched *sched = (struct cfs_wi_sched *)arg; - - cfs_block_allsigs(); - - /* CPT affinity scheduler? */ - if (sched->ws_cptab) - if (cfs_cpt_bind(sched->ws_cptab, sched->ws_cpt)) - CWARN("Unable to bind %s on CPU partition %d\n", - sched->ws_name, sched->ws_cpt); - - spin_lock(&cfs_wi_data.wi_glock); - - LASSERT(sched->ws_starting == 1); - sched->ws_starting--; - sched->ws_nthreads++; - - spin_unlock(&cfs_wi_data.wi_glock); - - spin_lock(&sched->ws_lock); - - while (!sched->ws_stopping) { - int nloops = 0; - int rc; - struct cfs_workitem *wi; - - while (!list_empty(&sched->ws_runq) && - nloops < CFS_WI_RESCHED) { - wi = list_entry(sched->ws_runq.next, - struct cfs_workitem, wi_list); - LASSERT(wi->wi_scheduled && !wi->wi_running); - - list_del_init(&wi->wi_list); - - LASSERT(sched->ws_nscheduled > 0); - sched->ws_nscheduled--; - - wi->wi_running = 1; - wi->wi_scheduled = 0; - - spin_unlock(&sched->ws_lock); - nloops++; - - rc = (*wi->wi_action)(wi); - - spin_lock(&sched->ws_lock); - if (rc) /* WI should be dead, even be freed! */ - continue; - - wi->wi_running = 0; - if (list_empty(&wi->wi_list)) - continue; - - LASSERT(wi->wi_scheduled); - /* wi is rescheduled, should be on rerunq now, we - * move it to runq so it can run action now - */ - list_move_tail(&wi->wi_list, &sched->ws_runq); - } - - if (!list_empty(&sched->ws_runq)) { - spin_unlock(&sched->ws_lock); - /* don't sleep because some workitems still - * expect me to come back soon - */ - cond_resched(); - spin_lock(&sched->ws_lock); - continue; - } - - spin_unlock(&sched->ws_lock); - rc = wait_event_interruptible_exclusive(sched->ws_waitq, - !cfs_wi_sched_cansleep(sched)); - spin_lock(&sched->ws_lock); - } - - spin_unlock(&sched->ws_lock); - - spin_lock(&cfs_wi_data.wi_glock); - sched->ws_nthreads--; - spin_unlock(&cfs_wi_data.wi_glock); - - return 0; -} - -void -cfs_wi_sched_destroy(struct cfs_wi_sched *sched) -{ - int i; - - LASSERT(cfs_wi_data.wi_init); - LASSERT(!cfs_wi_data.wi_stopping); - - spin_lock(&cfs_wi_data.wi_glock); - if (sched->ws_stopping) { - CDEBUG(D_INFO, "%s is in progress of stopping\n", - sched->ws_name); - spin_unlock(&cfs_wi_data.wi_glock); - return; - } - - LASSERT(!list_empty(&sched->ws_list)); - sched->ws_stopping = 1; - - spin_unlock(&cfs_wi_data.wi_glock); - - i = 2; - wake_up_all(&sched->ws_waitq); - - spin_lock(&cfs_wi_data.wi_glock); - while (sched->ws_nthreads > 0) { - CDEBUG(is_power_of_2(++i) ? D_WARNING : D_NET, - "waiting for %d threads of WI sched[%s] to terminate\n", - sched->ws_nthreads, sched->ws_name); - - spin_unlock(&cfs_wi_data.wi_glock); - set_current_state(TASK_UNINTERRUPTIBLE); - schedule_timeout(cfs_time_seconds(1) / 20); - spin_lock(&cfs_wi_data.wi_glock); - } - - list_del(&sched->ws_list); - - spin_unlock(&cfs_wi_data.wi_glock); - LASSERT(!sched->ws_nscheduled); - - kfree(sched); -} -EXPORT_SYMBOL(cfs_wi_sched_destroy); - -int -cfs_wi_sched_create(char *name, struct cfs_cpt_table *cptab, - int cpt, int nthrs, struct cfs_wi_sched **sched_pp) -{ - struct cfs_wi_sched *sched; - int rc; - - LASSERT(cfs_wi_data.wi_init); - LASSERT(!cfs_wi_data.wi_stopping); - LASSERT(!cptab || cpt == CFS_CPT_ANY || - (cpt >= 0 && cpt < cfs_cpt_number(cptab))); - - sched = kzalloc(sizeof(*sched), GFP_NOFS); - if (!sched) - return -ENOMEM; - - if (strlen(name) > sizeof(sched->ws_name) - 1) { - kfree(sched); - return -E2BIG; - } - strncpy(sched->ws_name, name, sizeof(sched->ws_name)); - - sched->ws_cptab = cptab; - sched->ws_cpt = cpt; - - spin_lock_init(&sched->ws_lock); - init_waitqueue_head(&sched->ws_waitq); - INIT_LIST_HEAD(&sched->ws_runq); - INIT_LIST_HEAD(&sched->ws_rerunq); - INIT_LIST_HEAD(&sched->ws_list); - - rc = 0; - while (nthrs > 0) { - char name[16]; - struct task_struct *task; - - spin_lock(&cfs_wi_data.wi_glock); - while (sched->ws_starting > 0) { - spin_unlock(&cfs_wi_data.wi_glock); - schedule(); - spin_lock(&cfs_wi_data.wi_glock); - } - - sched->ws_starting++; - spin_unlock(&cfs_wi_data.wi_glock); - - if (sched->ws_cptab && sched->ws_cpt >= 0) { - snprintf(name, sizeof(name), "%s_%02d_%02u", - sched->ws_name, sched->ws_cpt, - sched->ws_nthreads); - } else { - snprintf(name, sizeof(name), "%s_%02u", - sched->ws_name, sched->ws_nthreads); - } - - task = kthread_run(cfs_wi_scheduler, sched, "%s", name); - if (!IS_ERR(task)) { - nthrs--; - continue; - } - rc = PTR_ERR(task); - - CERROR("Failed to create thread for WI scheduler %s: %d\n", - name, rc); - - spin_lock(&cfs_wi_data.wi_glock); - - /* make up for cfs_wi_sched_destroy */ - list_add(&sched->ws_list, &cfs_wi_data.wi_scheds); - sched->ws_starting--; - - spin_unlock(&cfs_wi_data.wi_glock); - - cfs_wi_sched_destroy(sched); - return rc; - } - spin_lock(&cfs_wi_data.wi_glock); - list_add(&sched->ws_list, &cfs_wi_data.wi_scheds); - spin_unlock(&cfs_wi_data.wi_glock); - - *sched_pp = sched; - return 0; -} -EXPORT_SYMBOL(cfs_wi_sched_create); - -int -cfs_wi_startup(void) -{ - memset(&cfs_wi_data, 0, sizeof(cfs_wi_data)); - - spin_lock_init(&cfs_wi_data.wi_glock); - INIT_LIST_HEAD(&cfs_wi_data.wi_scheds); - cfs_wi_data.wi_init = 1; - - return 0; -} - -void -cfs_wi_shutdown(void) -{ - struct cfs_wi_sched *sched; - struct cfs_wi_sched *temp; - - spin_lock(&cfs_wi_data.wi_glock); - cfs_wi_data.wi_stopping = 1; - spin_unlock(&cfs_wi_data.wi_glock); - - /* nobody should contend on this list */ - list_for_each_entry(sched, &cfs_wi_data.wi_scheds, ws_list) { - sched->ws_stopping = 1; - wake_up_all(&sched->ws_waitq); - } - - list_for_each_entry(sched, &cfs_wi_data.wi_scheds, ws_list) { - spin_lock(&cfs_wi_data.wi_glock); - - while (sched->ws_nthreads) { - spin_unlock(&cfs_wi_data.wi_glock); - set_current_state(TASK_UNINTERRUPTIBLE); - schedule_timeout(cfs_time_seconds(1) / 20); - spin_lock(&cfs_wi_data.wi_glock); - } - spin_unlock(&cfs_wi_data.wi_glock); - } - list_for_each_entry_safe(sched, temp, &cfs_wi_data.wi_scheds, ws_list) { - list_del(&sched->ws_list); - kfree(sched); - } - - cfs_wi_data.wi_stopping = 0; - cfs_wi_data.wi_init = 0; -} -- 2.7.4