Paul E. McKenney
e0fcba9ac0
srcu: Make call_srcu() available during very early boot ...
Event tracing is moving to SRCU in order to take advantage of the fact
that SRCU may be safely used from idle and even offline CPUs. However,
event tracing can invoke call_srcu() very early in the boot process,
even before workqueue_init_early() is invoked (let alone rcu_init()).
Therefore, call_srcu()'s attempts to queue work fail miserably.
This commit therefore detects this situation, and refrains from attempting
to queue work before rcu_init() time, but does everything else that it
would have done, and in addition, adds the srcu_struct to a global list.
The rcu_init() function now invokes a new srcu_init() function, which
is empty if CONFIG_SRCU=n. Otherwise, srcu_init() queues work for
each srcu_struct on the list. This all happens early enough in boot
that there is but a single CPU with interrupts disabled, which allows
synchronization to be dispensed with.
Of course, the queued work won't actually be invoked until after
workqueue_init() is invoked, which happens shortly after the scheduler
is up and running. This means that although call_srcu() may be invoked
any time after per-CPU variables have been set up, there is still a very
narrow window when synchronize_srcu() won't work, and this window
extends from the time that the scheduler starts until the time that
workqueue_init() returns. This can be fixed in a manner similar to
the fix for synchronize_rcu_expedited() and friends, but until someone
actually needs to use synchronize_srcu() during this window, this fix
is added churn for no benefit.
Finally, note that Tree SRCU's new srcu_init() function invokes
queue_work() rather than the queue_delayed_work() function that is
invoked post-boot. The reason is that queue_delayed_work() will (as you
would expect) post a timer, and timers have not yet been initialized.
So use of queue_work() avoids the complaints about use of uninitialized
spinlocks that would otherwise result. Besides, some delay is already
provide by the aforementioned fact that the queued work won't actually
be invoked until after the scheduler is up and running.
Requested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-30 16:10:19 -07:00
bpf: fix redirect to map under tail calls
2018-08-17 15:56:23 -07:00
Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2018-08-24 13:19:27 -07:00
kconfig: tinyconfig: remove stale stack protector fixups
2018-06-15 07:15:28 +09:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from_contiguous()
2018-08-17 16:20:32 -07:00
treewide: convert ISO_8859-1 text comments to utf-8
2018-08-23 18:48:43 -07:00
gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT
2018-06-08 18:56:02 +09:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 10:47:26 -07:00
Merge branch 'for-4.19/upstream' into for-linus
2018-08-20 18:33:50 +02:00
Updates for v4.19:
2018-08-20 18:32:00 -07:00
PM / sleep: wakeup: Fix build error caused by missing SRCU support
2018-08-15 00:07:08 +02:00
fbdev changes for v4.19:
2018-08-23 15:44:58 -07:00
srcu: Make call_srcu() available during very early boot
2018-08-30 16:10:19 -07:00
Merge branch 'akpm' (patches from Andrew)
2018-08-22 12:34:08 -07:00
Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2018-08-21 13:47:29 -07:00
Masami found an off by one bug in the code that keeps "notrace" functions
2018-08-23 13:07:00 -07:00
kernel/acct.c: fix the acct->needcheck check in check_free_space()
2018-01-04 16:45:09 -08:00
kernel/async.c: revert "async: simplify lowest_in_progress()"
2018-02-06 18:32:44 -08:00
audit: use ktime_get_coarse_real_ts64() for timestamps
2018-07-17 14:45:08 -04:00
audit: track the owner of the command mutex ourselves
2018-02-23 11:22:22 -05:00
fsnotify: add fsnotify_add_inode_mark() wrappers
2018-05-18 14:58:22 +02:00
\n
2018-08-17 09:41:28 -07:00
audit: fix use-after-free in audit_add_watch
2018-07-18 11:43:36 -04:00
audit: rename FILTER_TYPE to FILTER_EXCLUDE
2018-06-19 10:39:54 -04:00
audit/stable-4.18 PR 20180814
2018-08-15 10:46:54 -07:00
time: Enable get/put_compat_itimerspec64 always
2018-06-24 14:39:47 +02:00
cpu/hotplug: Non-SMP machines do not make use of booted_once
2018-08-14 15:00:00 -07:00
kernel/crash_core.c: print timestamp using time64_t
2018-08-22 10:52:47 -07:00
delayacct: Use raw_spinlocks
2018-04-27 14:34:51 +02:00
proc: introduce proc_create_single{,_data}
2018-05-16 07:23:35 +02:00
proc: introduce proc_create_single{,_data}
2018-05-16 07:23:35 +02:00
signal: Pass pid type into group_send_sig_info
2018-07-21 12:57:35 -05:00
extable: Make init_kernel_text() global
2018-02-21 16:54:06 +01:00
bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe
2018-06-21 12:33:19 +02:00
Merge branch 'akpm' (patches from Andrew)
2018-08-22 12:34:08 -07:00
PM / reboot: Eliminate race between reboot and suspend
2018-08-06 12:35:20 +02:00
futex: Mark expected switch fall-throughs
2018-08-20 18:23:00 +02:00
kernel: make groups_sort calling a responsibility group_info allocators
2017-12-14 16:00:49 -08:00
kernel/hung_task.c: allow to set checking interval separately from timeout
2018-08-22 10:52:47 -07:00
memremap: split devm_memremap_pages() and memremap() infrastructure
2018-05-15 23:08:33 -07:00
irq/work: Improve the flag definitions
2018-01-08 19:43:15 +01:00
jump_label: Disable jump labels in __exit code
2018-03-20 08:57:17 +01:00
kallsyms, x86: Export addresses of PTI entry trampolines
2018-08-14 19:12:29 -03:00
kconfig: include kernel/Kconfig.preempt from init/Kconfig
2018-08-02 08:06:54 +09:00
sched/core / kcov: avoid kcov_area during task switch
2018-06-15 07:55:24 +09:00
kexec: add call to LSM hook in original kexec_load syscall
2018-07-16 12:31:57 -07:00
kexec: yield to scheduler when loading kimage segments
2018-06-15 07:55:24 +09:00
treewide: Use array_size() in vzalloc()
2018-06-12 16:19:22 -07:00
kprobes: Replace %p with other pointer types
2018-06-21 17:33:42 +02:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
kbuild: move bin2c back to scripts/ from scripts/basic/
2018-07-18 01:18:05 +09:00
libnvdimm-for-4.19_dax-memory-failure
2018-08-25 18:43:59 -07:00
modsign: log module name in the event of an error
2018-07-02 11:36:17 +02:00
module: use relative references for __ksymtab entries
2018-08-22 10:52:47 -07:00
modsign: log module name in the event of an error
2018-07-02 11:36:17 +02:00
padata: add SPDX identifier
2018-01-05 18:43:00 +11:00
Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
2018-06-14 12:21:18 +09:00
kernel/params.c: downgrade warning for unsafe parameters
2018-04-11 10:28:37 -07:00
pid: Implement PIDTYPE_TGID
2018-07-21 10:43:12 -05:00
Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2018-04-03 19:15:32 -07:00
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
PM / reboot: Eliminate race between reboot and suspend
2018-08-06 12:35:20 +02:00
kernel/relay.c: change return type to vm_fault_t
2018-06-15 07:55:24 +09:00
libnvdimm for 4.18
2018-06-08 17:21:52 -07:00
rseq: uapi: Declare rseq_cs field as union, update includes
2018-07-10 22:18:52 +02:00
audit/stable-4.18 PR 20180605
2018-06-06 16:34:00 -07:00
Merge branch 'akpm' (patches from Andrew)
2018-08-22 12:34:08 -07:00
cpu/hotplug: Fix SMT supported evaluation
2018-08-07 12:25:30 +02:00
smpboot: Remove cpumask from the API
2018-07-03 09:20:44 +02:00
nohz: Fix missing tick reprogram when interrupting an inline softirq
2018-08-03 15:52:10 +02:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2018-08-24 09:25:39 -07:00
Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-06-10 10:17:09 -07:00
namei: allow restricted O_CREAT of FIFOs and regular files
2018-08-23 18:48:43 -07:00
staging: irda: remove remaining remants of irda code removal
2018-04-16 11:26:49 +02:00
locking/barriers: Convert users of lockless_dereference() to READ_ONCE()
2017-12-17 13:57:15 +01:00
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
kprobes: Remove jprobe API implementation
2018-06-21 12:33:05 +02:00
torture: Keep old-school dmesg format
2018-06-25 11:30:10 -07:00
kernel: tracepoints: add support for relative references
2018-08-22 10:52:47 -07:00
headers: untangle kmemleak.h from mm.h
2018-04-05 21:36:27 -07:00
fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers
2018-04-02 20:15:59 +02:00
kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c
2018-04-02 20:15:30 +02:00
umh: fix race condition
2018-06-07 16:56:28 -04:00
userns: use irqsave variant of refcount_dec_and_lock()
2018-08-22 10:52:47 -07:00
userns: move user access out of the mutex
2018-08-11 02:05:53 -05:00
uts: create "struct uts_namespace" from kmem_cache
2018-04-11 10:28:35 -07:00
sys: don't hold uts_sem while accessing userspace memory
2018-08-11 02:05:53 -05:00
watchdog/softlockup: Fix cpu_stop_queue_work() double-queue bug
2018-07-15 23:51:19 +02:00
watchdog: Reduce message verbosity
2018-08-03 12:19:08 +02:00
Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2018-08-24 13:16:36 -07:00
workqueue: Set worker->desc to workqueue name by default
2018-05-18 08:47:13 -07:00
e0fcba9ac0