linux/kernel
Daniel Jordan 004ed42638 padata: add basic support for multithreaded jobs
Sometimes the kernel doesn't take full advantage of system memory
bandwidth, leading to a single CPU spending excessive time in
initialization paths where the data scales with memory size.

Multithreading naturally addresses this problem.

Extend padata, a framework that handles many parallel yet singlethreaded
jobs, to also handle multithreaded jobs by adding support for splitting up
the work evenly, specifying a minimum amount of work that's appropriate
for one helper thread to do, load balancing between helpers, and
coordinating them.

This is inspired by work from Pavel Tatashin and Steve Sistare.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Josh Triplett <josh@joshtriplett.org>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Robert Elliott <elliott@hpe.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/20200527173608.2885243-5-daniel.m.jordan@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:45 -07:00
..
bpf mm: remove vmalloc_user_node_flags 2020-06-02 10:59:11 -07:00
cgroup Revert "cgroup: Add memory barriers to plug cgroup_rstat_updated() race window" 2020-04-09 14:55:46 -04:00
configs compiler: remove CONFIG_OPTIMIZE_INLINING entirely 2020-04-07 10:43:42 -07:00
debug SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
dma dma-mapping: use vmap insted of reimplementing it 2020-06-02 10:59:10 -07:00
events Linux 5.7-rc7 2020-05-28 07:58:12 +02:00
gcov kernel/gcov/fs.c: gcov_seq_next() should increase position index 2020-04-10 15:36:22 -07:00
irq genirq: Remove setup_irq() and remove_irq() 2020-04-14 10:08:50 +02:00
livepatch New tracing features: 2019-11-27 11:42:01 -08:00
locking The biggest change to core locking facilities in this cycle is the introduction 2020-06-01 13:03:31 -07:00
power PM: hibernate: Restrict writes to the resume device 2020-05-27 17:55:59 +02:00
printk The RCU updates for this cycle were: 2020-06-01 12:56:29 -07:00
rcu Merge branch 'WIP.core/rcu' into core/rcu, to pick up two x86/entry dependencies 2020-06-01 11:47:29 +02:00
sched arm64 updates for 5.8 2020-06-01 15:18:27 -07:00
time proc, time/namespace: Show clock symbolic names in /proc/pid/timens_offsets 2020-04-16 12:10:54 +02:00
trace for-5.8/block-2020-06-01 2020-06-02 15:29:19 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
acct.c acct: stop using get_seconds() 2019-12-18 18:07:31 +01:00
async.c
audit_fsnotify.c fsnotify: use helpers to access data by data_type 2020-03-23 18:19:06 +01:00
audit_tree.c
audit_watch.c \n 2020-04-06 08:58:42 -07:00
audit.c audit/stable-5.8 PR 20200601 2020-06-02 17:13:37 -07:00
audit.h audit: fix a net reference leak in audit_list_rules_send() 2020-04-22 15:23:10 -04:00
auditfilter.c audit: fix a net reference leak in audit_list_rules_send() 2020-04-22 15:23:10 -04:00
auditsc.c audit: add subj creds to NETFILTER_CFG record to 2020-05-20 18:09:19 -04:00
backtracetest.c
bounds.c
capability.c
compat.c uaccess: Selectively open read or write user access 2020-05-01 12:35:21 +10:00
configs.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
context_tracking.c context-tracking: Introduce CONFIG_HAVE_TIF_NOHZ 2020-02-14 16:05:04 +01:00
cpu_pm.c
cpu.c cpu/hotplug: Remove __freeze_secondary_cpus() 2020-05-07 15:18:41 +02:00
crash_core.c
crash_dump.c crash_dump: Remove no longer used saved_max_pfn 2020-04-15 11:21:54 +02:00
cred.c kernel: doc: remove outdated comment cred.c 2020-03-25 10:04:01 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c Merge branch 'uaccess.readdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-06-01 16:11:38 -07:00
extable.c kernel/extable.c: use address-of operator on section symbols 2020-04-07 10:43:42 -07:00
fail_function.c
fork.c arm64 updates for 5.8 2020-06-01 15:18:27 -07:00
freezer.c
futex.c futex: get rid of a kernel-docs build warning 2020-04-20 15:45:41 -06:00
gen_kheaders.sh kheaders: explain why include/config/autoconf.h is excluded from md5sum 2019-11-11 20:10:01 +09:00
groups.c mm: remove the pgprot argument to __vmalloc 2020-06-02 10:59:11 -07:00
hung_task.c
iomem.c
irq_work.c lockdep: Annotate irq_work 2020-03-21 16:00:24 +01:00
jump_label.c
kallsyms.c kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() 2020-04-07 10:43:44 -07:00
kcmp.c kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve 2020-03-25 10:04:01 -05:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks sched/rt, locking: Use CONFIG_PREEMPTION 2019-12-08 14:37:36 +01:00
Kconfig.preempt sched/Kconfig: Fix spelling mistake in user-visible help text 2019-11-12 11:35:32 +01:00
kcov.c kernel/kcov.c: fix typos in kcov_remote_start documentation 2020-05-07 19:27:20 -07:00
kexec_core.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_elf.c
kexec_file.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_internal.h kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kheaders.c
kmod.c kmod: make request_module() return an error when autoloading is disabled 2020-04-10 15:36:22 -07:00
kprobes.c kprobes: Prevent probes in .noinstr.text section 2020-05-19 15:56:20 +02:00
ksysfs.c
kthread.c kthread: Do not preempt current task if it is going to call schedule() 2020-03-20 13:06:20 +01:00
latencytop.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
Makefile scs: Add support for Clang's Shadow Call Stack (SCS) 2020-05-15 16:35:45 +01:00
module_signature.c
module_signing.c
module-internal.h
module.c Merge branch 'akpm' (patches from Andrew) 2020-06-02 12:21:36 -07:00
notifier.c mm: remove vmalloc_sync_(un)mappings() 2020-06-02 10:59:12 -07:00
nsproxy.c ns: Introduce Time Namespace 2020-01-14 12:20:48 +01:00
padata.c padata: add basic support for multithreaded jobs 2020-06-03 20:09:45 -07:00
panic.c locking/refcount: Remove unused 'refcount_error_report()' function 2019-11-25 09:15:42 +01:00
params.c
pid_namespace.c pid: Improve the comment about waiting in zap_pid_ns_processes 2020-02-28 16:29:12 -06:00
pid.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-04-10 12:59:56 -07:00
profile.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
ptrace.c ptrace: reintroduce usage of subjective credentials in ptrace_has_cap() 2020-01-18 13:51:39 +01:00
range.c
reboot.c printk: Collapse shutdown types into a single dump reason 2020-05-30 10:34:03 -07:00
relay.c docs: filesystems: fix renamed references 2020-04-20 15:45:22 -06:00
resource.c
rseq.c rseq: Reject unknown flags on rseq unregister 2019-12-25 10:41:20 +01:00
scs.c scs: Remove references to asm/scs.h from core code 2020-05-18 17:47:45 +01:00
seccomp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
signal.c Merge branch 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-06-01 16:21:46 -07:00
smp.c smp: Use smp_call_func_t in on_each_cpu() 2020-04-19 17:51:48 +02:00
smpboot.c
smpboot.h
softirq.c lockdep: Rename trace_{hard,soft}{irq_context,irqs_enabled}() 2020-03-21 16:03:54 +01:00
stackleak.c
stacktrace.c stacktrace: Get rid of unneeded '!!' pattern 2019-11-11 10:30:59 +01:00
stop_machine.c stop_machine: Make stop_cpus() static 2020-01-17 10:19:21 +01:00
sys_ni.c y2038: allow disabling time32 system calls 2019-11-15 14:38:30 +01:00
sys.c Merge branch 'akpm' (patches from Andrew) 2020-06-02 12:21:36 -07:00
sysctl_binary.c sysctl: Remove the sysctl system call 2019-11-26 13:03:56 -06:00
sysctl-test.c kunit: allow kunit tests to be loaded as a module 2020-01-09 16:42:29 -07:00
sysctl.c Revert "docs: sysctl/kernel: document ngroups_max" 2020-05-18 06:19:25 -06:00
task_work.c task_work_run: don't take ->pi_lock unconditionally 2020-03-02 14:06:33 -07:00
taskstats.c taskstats: fix data-race 2019-12-04 15:18:39 +01:00
test_kprobes.c
torture.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
tracepoint.c
tsacct.c tsacct: add 64-bit btime field 2019-12-18 18:07:31 +01:00
ucount.c ucount: Make sure ucounts in /proc/sys/user don't regress again 2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-15 13:10:06 -07:00
up.c smp/up: Make smp_call_function_single() match SMP semantics 2020-02-07 15:34:12 +01:00
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog_hld.c
watchdog.c watchdog/softlockup: Enforce that timestamp is valid on boot 2020-01-17 11:19:22 +01:00
workqueue_internal.h
workqueue.c workqueue: Remove the warning in wq_worker_sleeping() 2020-04-08 11:35:20 +02:00