The patch titled
workqueue: remove lock_cpu_hotplug()
has been removed from the -mm tree. Its filename is
workqueue-remove-lock_cpu_hotplug.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: workqueue: remove lock_cpu_hotplug()
From: Andrew Morton <akpm@xxxxxxxx>
Use a private lock instead. It protects all per-cpu data structures in
workqueue.c, including the workqueues list.
Fix a bug in schedule_on_each_cpu(): it was forgetting to lock down the
per-cpu resources.
Unfixed long-standing bug: if someone unplugs the CPU identified by
`singlethread_cpu' the kernel will get very sick.
Cc: Dave Jones <davej@xxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/workqueue.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)
diff -puN kernel/workqueue.c~workqueue-remove-lock_cpu_hotplug kernel/workqueue.c
--- a/kernel/workqueue.c~workqueue-remove-lock_cpu_hotplug
+++ a/kernel/workqueue.c
@@ -68,7 +68,7 @@ struct workqueue_struct {
/* All the per-cpu workqueues on the system, for hotplug cpu to add/remove
threads to each one as cpus come/go. */
-static DEFINE_SPINLOCK(workqueue_lock);
+static DEFINE_MUTEX(workqueue_mutex);
static LIST_HEAD(workqueues);
static int singlethread_cpu;
@@ -320,10 +320,10 @@ void fastcall flush_workqueue(struct wor
} else {
int cpu;
- lock_cpu_hotplug();
+ mutex_lock(&workqueue_mutex);
for_each_online_cpu(cpu)
flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu));
- unlock_cpu_hotplug();
+ mutex_unlock(&workqueue_mutex);
}
}
EXPORT_SYMBOL_GPL(flush_workqueue);
@@ -371,8 +371,7 @@ struct workqueue_struct *__create_workqu
}
wq->name = name;
- /* We don't need the distraction of CPUs appearing and vanishing. */
- lock_cpu_hotplug();
+ mutex_lock(&workqueue_mutex);
if (singlethread) {
INIT_LIST_HEAD(&wq->list);
p = create_workqueue_thread(wq, singlethread_cpu);
@@ -381,9 +380,7 @@ struct workqueue_struct *__create_workqu
else
wake_up_process(p);
} else {
- spin_lock(&workqueue_lock);
list_add(&wq->list, &workqueues);
- spin_unlock(&workqueue_lock);
for_each_online_cpu(cpu) {
p = create_workqueue_thread(wq, cpu);
if (p) {
@@ -393,7 +390,7 @@ struct workqueue_struct *__create_workqu
destroy = 1;
}
}
- unlock_cpu_hotplug();
+ mutex_unlock(&workqueue_mutex);
/*
* Was there any error during startup? If yes then clean up:
@@ -434,17 +431,15 @@ void destroy_workqueue(struct workqueue_
flush_workqueue(wq);
/* We don't need the distraction of CPUs appearing and vanishing. */
- lock_cpu_hotplug();
+ mutex_lock(&workqueue_mutex);
if (is_single_threaded(wq))
cleanup_workqueue_thread(wq, singlethread_cpu);
else {
for_each_online_cpu(cpu)
cleanup_workqueue_thread(wq, cpu);
- spin_lock(&workqueue_lock);
list_del(&wq->list);
- spin_unlock(&workqueue_lock);
}
- unlock_cpu_hotplug();
+ mutex_unlock(&workqueue_mutex);
free_percpu(wq->cpu_wq);
kfree(wq);
}
@@ -515,11 +510,13 @@ int schedule_on_each_cpu(void (*func)(vo
if (!works)
return -ENOMEM;
+ mutex_lock(&workqueue_mutex);
for_each_online_cpu(cpu) {
INIT_WORK(per_cpu_ptr(works, cpu), func, info);
__queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu),
per_cpu_ptr(works, cpu));
}
+ mutex_unlock(&workqueue_mutex);
flush_workqueue(keventd_wq);
free_percpu(works);
return 0;
@@ -635,6 +632,7 @@ static int __devinit workqueue_cpu_callb
switch (action) {
case CPU_UP_PREPARE:
+ mutex_lock(&workqueue_mutex);
/* Create a new workqueue thread for it. */
list_for_each_entry(wq, &workqueues, list) {
if (!create_workqueue_thread(wq, hotcpu)) {
@@ -653,6 +651,7 @@ static int __devinit workqueue_cpu_callb
kthread_bind(cwq->thread, hotcpu);
wake_up_process(cwq->thread);
}
+ mutex_unlock(&workqueue_mutex);
break;
case CPU_UP_CANCELED:
@@ -664,6 +663,15 @@ static int __devinit workqueue_cpu_callb
any_online_cpu(cpu_online_map));
cleanup_workqueue_thread(wq, hotcpu);
}
+ mutex_unlock(&workqueue_mutex);
+ break;
+
+ case CPU_DOWN_PREPARE:
+ mutex_lock(&workqueue_mutex);
+ break;
+
+ case CPU_DOWN_FAILED:
+ mutex_unlock(&workqueue_mutex);
break;
case CPU_DEAD:
@@ -671,6 +679,7 @@ static int __devinit workqueue_cpu_callb
cleanup_workqueue_thread(wq, hotcpu);
list_for_each_entry(wq, &workqueues, list)
take_over_work(wq, hotcpu);
+ mutex_unlock(&workqueue_mutex);
break;
}
_
Patches currently in -mm which might be from akpm@xxxxxxxx are
origin.patch
oops-on-boot-fix-for-ide.patch
revert-input-wistron-fix-section-reference-mismatches.patch
lockdep-fix-blkdev_open-warning-fix.patch
git-acpi.patch
acpi-asus-s3-resume-fix.patch
sony_apci-resume.patch
kauditd_thread-warning-fix.patch
revert-gregkh-driver-class_device_rename-remove.patch
revert-gregkh-driver-network-class_device-to-device.patch
revert-gregkh-driver-tty-device.patch
revert-gregkh-driver-mem-devices.patch
add-__must_check-to-device-management-code.patch
add-config_enable_must_check.patch
v4l-dev2-handle-__must_check.patch
drivers-base-check-errors.patch
sysfs-add-proper-sysfs_init-prototype.patch
scsi-device_reprobe-can-fail.patch
git-drm.patch
git-gfs2.patch
git-ia64.patch
git-ieee1394-fixup.patch
git-input.patch
git-kbuild.patch
git-libata-all.patch
asus-mv-device-ids.patch
1-of-2-jmicron-driver-hard_port_no-fix.patch
git-netdev-all.patch
drivers-net-ns83820c-add-paramter-to-disable-auto.patch
git-nfs.patch
git-pcmcia-fixup.patch
git-powerpc.patch
git-sas.patch
git-block-vs-git-sas.patch
tickle-nmi-watchdog-on-serial-output-fix.patch
serial-fix-uart_bug_txen-test.patch
revert-gregkh-pci-pci-use-pci_bios-as-last-fallback.patch
pcie-check-and-return-bus_register-errors-fix.patch
git-scsi-misc.patch
revert-scsi-improve-inquiry-printing.patch
fix-panic-when-reinserting-adaptec-pcmcia-scsi-card.patch
git-scsi-target-fixup.patch
git-scsi-target-vs-git-block.patch
usb-hub-driver-improve-use-of-ifdef-fix.patch
pm-usb-hcds-use-pm_event_prethaw-fix.patch
rtl8150_disconnect-needs-tasklet_kill.patch
git-supertrak-fixup.patch
git-watchdog.patch
kthread-airoc.patch
revert-x86_64-mm-i386-remove-lock-section.patch
revert-x86_64-mm-detect-cfi.patch
x86_64-wire-up-oops_enter-oops_exit.patch
git-cryptodev-fixup.patch
git-cryptodev-broke-geode-aes.patch
adix-tree-rcu-lockless-readside-update-tidy.patch
mm-tracking-shared-dirty-pages-checks.patch
mm-tracking-shared-dirty-pages-wimp.patch
convert-i386-numa-kva-space-to-bootmem-tidy.patch
reduce-max_nr_zones-make-display-of-highmem-counters-conditional-on-config_highmem-tidy.patch
reduce-max_nr_zones-use-enum-to-define-zones-reformat-and-comment-cleanup.patch
reduce-max_nr_zones-use-enum-to-define-zones-reformat-and-comment-fix.patch
reduce-max_nr_zones-remove-display-of-counters-for-unconfigured-zones-s390-fix.patch
out-of-memory-notifier-tidy.patch
mm-swap-write-failure-fixup-fix.patch
slab-optimize-kmalloc_node-the-same-way-as-kmalloc-fix.patch
slab-fix-lockdep-warnings-fix-2.patch
acx1xx-wireless-driver.patch
tiacx-pci-build-fix.patch
tiacx-ia64-fix.patch
tiacx-build-fix.patch
binfmt_elf-consistently-use-loff_t.patch
convert-i386-summit-subarch-to-use-srat-info-for-apicid_to_node-calls-tidy.patch
x86-increase-max_mp_busses-on-default-arch.patch
i386-adds-smp_call_function_single-fix.patch
swsusp-write-timer.patch
swsusp-write-speedup.patch
swsusp-read-timer.patch
swsusp-read-speedup.patch
swsusp-read-speedup-fix.patch
swsusp-read-speedup-cleanup.patch
swsusp-read-speedup-cleanup-2.patch
swsusp-read-speedup-fix-fix-2.patch
deprecate-smbfs-in-favour-of-cifs.patch
edac-new-opteron-athlon64-memory-controller-driver-tidy.patch
inode_diet-replace-inodeugeneric_ip-with-inodei_private-gfs-fix.patch
x86-microcode-microcode-driver-cleanup-tidy.patch
x86-microcode-add-sysfs-and-hotplug-support-fix.patch
eisa-bus-modalias-attributes-support-1-fix-git-kbuild-fix.patch
add-address_space_operationsbatch_write-fix.patch
alloc_fdtable-cleanup.patch
add-probe_kernel_address.patch
x86-use-probe_kernel_address-in-handle_bug.patch
blockdevc-check-errors.patch
let-warn_on-warn_on_once-return-the-condition-fix.patch
let-warn_on-warn_on_once-return-the-condition-fix-2.patch
omap-add-watchdog-driver-support-tweaks.patch
move-valid_dma_direction-from-x86_64-to-generic-code-fix.patch
single-bit-flip-detector-tidy.patch
fix-unserialized-task-files-changing-fix.patch
tty-make-termios_sem-a-mutex-fix.patch
ntp-move-all-the-ntp-related-code-to-ntpc-fix.patch
reiserfs-on-demand-bitmap-loading.patch
streamline-generic_file_-interfaces-and-filemap-gfs-fix.patch
add-vector-aio-support-fix.patch
csa-basic-accounting-over-taskstats-fix.patch
fs-cache-make-kafs-use-fs-cache-fix.patch
fs-cache-make-kafs-use-fs-cache-vs-streamline-generic_file_-interfaces-and-filemap.patch
nfs-use-local-caching-12-fix.patch
stack-overflow-safe-kdump-crash_use_safe_smp_processor_id-fix.patch
vfs-make-filldir_t-and-struct-kstat-deal-in-64-bit-inode-numbers-alpha-fix.patch
some-cleanup-in-the-pipe-code-tidy.patch
support-piping-into-commands-in-proc-sys-kernel-core_pattern-fix.patch
move-pidmap-to-pspaceh-fix.patch
isdn-work-around-excessive-udelay.patch
knfsd-add-a-callback-for-when-last-rpc-thread-finishes-tidy.patch
knfsd-add-a-callback-for-when-last-rpc-thread-finishes-fix.patch
knfsd-separate-out-some-parts-of-nfsd_svc-which-start-nfs-servers-tweaks.patch
knfsd-define-new-nfsdfs-file-portlist-contains-list-of-ports-tidy.patch
knfsd-define-new-nfsdfs-file-portlist-contains-list-of-ports-fix.patch
knfsd-have-ext2-reject-file-handles-with-bad-inode-numbers-early-tidy.patch
knfsd-make-ext3-reject-filehandles-referring-to-invalid-inode-numbers-tidy.patch
knfsd-drop-serv-option-to-svc_recv-and-svc_process-nfs-callback-fix-nfs-callback-fix.patch
knfsd-move-tempsock-aging-to-a-timer-tidy.patch
sched-remove-unnecessary-sched-group-allocations-fix.patch
swap_prefetch-vs-zoned-counters.patch
ecryptfs-mmap-operations.patch
ecryptfs-alpha-build-fix.patch
ecryptfs-more-elegant-aes-key-size-manipulation.patch
ecryptfs-get_sb_dev-fix.patch
namespaces-add-nsproxy-dont-include-compileh.patch
namespaces-utsname-switch-to-using-uts-namespaces.patch
namespaces-utsname-use-init_utsname-when-appropriate.patch
namespaces-utsname-use-init_utsname-when-appropriate-gmidi.patch
namespaces-utsname-use-init_utsname-when-appropriate-print_kernel_version.patch
namespaces-utsname-implement-utsname-namespaces.patch
namespaces-utsname-sysctl-hack.patch
namespaces-utsname-switch-to-using-uts-namespaces-klibc-bit-sparc.patch
ipc-namespace-core.patch
readahead-sysctl-parameters-fix.patch
make-copy_from_user_inatomic-not-zero-the-tail-on-i386-vs-reiser4.patch
reiser4-hardirq-include-fix.patch
reiser4-run-truncate_inode_pages-in-reiser4_delete_inode.patch
reiser4-get_sb_dev-fix.patch
reiser4-vs-zoned-allocator.patch
reiser4-rename-generic_sounding_globalspatch-fix.patch
hpt3xx-rework-rate-filtering-tidy.patch
asus-mv-ide-device-ids.patch
genirq-convert-the-i386-architecture-to-irq-chips.patch
genirq-x86_64-irq-reenable-migrating-irqs-to-other-cpus.patch
genirq-msi-simplify-msi-enable-and-disable.patch
genirq-ia64-irq-dynamic-irq-support.patch
genirq-msi-only-build-msi-apicc-on-ia64-fix.patch
genirq-i386-irq-remove-the-msi-assumption-that-irq-==-vector.patch
genirq-x86_64-irq-make-vector_irq-per-cpu-fix.patch
genirq-x86_64-irq-make-vector_irq-per-cpu-warning-fix.patch
add-hypertransport-capability-defines-fix.patch
initial-generic-hypertransport-interrupt-support-Kconfig-fix.patch
srcu-report-out-of-memory-errors-fixlet.patch
nr_blockdev_pages-in_interrupt-warning.patch
device-suspend-debug.patch
slab-leaks3-default-y.patch
x86-kmap_atomic-debugging.patch
restore-rogue-readahead-printk.patch
input_register_device-debug.patch
put_bh-debug.patch
jmicron-warning-fix.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
