Davidlohr Bueso
07879c6a37
sched/wake_q: Reduce reference counting for special users ...
Some users, specifically futexes and rwsems, required fixes
that allowed the callers to be safe when wakeups occur before
they are expected by wake_up_q(). Such scenarios also play
games and rely on reference counting, and until now were
pivoting on wake_q doing it. With the wake_q_add() call being
moved down, this can no longer be the case. As such we end up
with a a double task refcounting overhead; and these callers
care enough about this (being rather core-ish).
This patch introduces a wake_q_add_safe() call that serves
for callers that have already done refcounting and therefore the
task is 'safe' from wake_q point of view (int that it requires
reference throughout the entire queue/>wakeup cycle). In the one
case it has internal reference counting, in the other case it
consumes the reference counting.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Xie Yongji <xieyongji@baidu.com>
Cc: Yongji Xie <elohimes@gmail.com>
Cc: andrea.parri@amarulasolutions.com
Cc: lilin24@baidu.com
Cc: liuqi16@baidu.com
Cc: nixun@baidu.com
Cc: yuanlinsi01@baidu.com
Cc: zhangyu31@baidu.com
Link: https://lkml.kernel.org/r/20181218195352.7orq3upiwfdbrdne@linux-r8p5
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04 09:03:28 +01:00
bpf: fix inner map masking to prevent oob under speculation
2019-01-18 15:19:56 -08:00
Merge branch 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2018-12-29 10:57:20 -08:00
kvm_config: add CONFIG_VIRTIO_MENU
2018-10-24 20:55:56 -04:00
kdb: use bool for binary state indicators
2018-12-30 08:31:52 +00:00
swiotlb: clear io_tlb_start and io_tlb_end in swiotlb_exit
2019-01-16 09:59:17 -05:00
perf core: Fix perf_proc_update_handler() bug
2019-01-18 11:10:38 -03:00
genirq/irqdesc: Fix double increment in alloc_descs()
2019-01-18 00:43:09 +01:00
livepatch: Replace synchronize_sched() with synchronize_rcu()
2018-12-01 12:38:50 -08:00
sched/wake_q: Reduce reference counting for special users
2019-02-04 09:03:28 +01:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
rcutorture: Don't do busted forward-progress testing
2018-12-01 12:45:42 -08:00
sched/wake_q: Reduce reference counting for special users
2019-02-04 09:03:28 +01:00
posix-cpu-timers: Unbreak timer rearming
2019-01-15 16:34:37 +01:00
tracing/kprobes: Fix NULL pointer dereference in trace_kprobe_create()
2019-01-15 11:33:45 -05:00
audit: remove duplicated include from audit.c
2018-12-14 12:09:30 -05:00
audit: use current whenever possible
2018-11-26 18:41:21 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: use current whenever possible
2018-11-26 18:41:21 -05:00
kbuild: fix kernel/bounds.c 'W=1' warning
2018-10-31 08:54:14 -07:00
make 'user_access_begin()' do 'access_ok()'
2019-01-04 12:56:09 -08:00
Linux 5.0-rc5
2019-02-04 08:57:24 +01:00
cred: export get_task_cred().
2018-12-19 13:52:44 -05:00
delayacct: track delays from thrashing cache pages
2018-10-26 16:26:32 -07:00
kernel/exit.c: release ptraced tasks before zap_pid_ns_processes
2019-02-01 15:46:23 -08:00
kernel/fail_function.c: remove meaningless null pointer check before debugfs_remove_recursive
2018-10-31 08:54:12 -07:00
Merge branch 'akpm' (patches from Andrew)
2019-01-08 18:58:29 -08:00
sched/wake_q: Reduce reference counting for special users
2019-02-04 09:03:28 +01:00
kernel/hung_task.c: break RCU locks based on jiffies
2019-01-04 13:13:45 -08:00
jump_label: move 'asm goto' support test to Kconfig
2019-01-06 09:46:51 +09:00
kallsyms: reduce size a little on 64-bit
2018-09-10 22:54:33 +09:00
kconfig: warn no new line at end of file
2018-12-15 17:44:35 +09:00
kernel/kcov.c: mark write_comp_data() as notrace
2019-01-04 13:13:47 -08:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
kexec_file: kexec_walk_memblock() only walks a dedicated region at kdump
2018-12-06 14:38:50 +00:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-12-26 14:45:18 -08:00
kbuild: change filechk to surround the given command with { }
2019-01-06 09:46:51 +09:00
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
2018-12-28 12:11:52 -08:00
jump_label: move 'asm goto' support test to Kconfig
2019-01-06 09:46:51 +09:00
modsign: use all trusted keys to verify module signature
2018-11-07 14:41:41 +01:00
padata: clean an indentation issue, remove extraneous space
2018-11-16 14:11:04 +08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
Fix failure path in alloc_pid()
2018-12-28 12:42:30 -08:00
signal: Use group_send_sig_info to kill all processes in a pid namespace
2018-09-16 16:08:25 +02:00
mm: remove include/linux/bootmem.h
2018-10-31 08:54:16 -07:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
kernel/reboot.c: export pm_power_off_prepare
2018-09-11 16:13:24 +01:00
kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustable
2018-12-28 12:11:49 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
seccomp: fix UAF in user-trap code
2019-01-15 09:43:12 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM
2019-01-30 19:27:00 +01:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-10-25 11:43:47 -07:00
stackleak: Mark stackleak_track_stack() as notrace
2018-12-05 19:31:44 -08:00
kernel/sys.c: Clarify that UNAME26 does not generate unique versions anymore
2019-01-14 10:38:03 +12:00
y2038: socket: Add compat_sys_recvmmsg_time64
2018-12-18 16:13:04 +01:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
torture: Remove unnecessary "ret" variables
2018-12-01 12:45:35 -08:00
tracing: Replace synchronize_sched() and call_rcu_sched()
2018-11-27 09:21:41 -08:00
umh: add exit routine for UMH process
2019-01-11 18:05:40 -08:00
smp,cpumask: introduce on_each_cpu_cond_mask
2018-10-09 16:51:11 +02:00
userns: also map extents in the reverse map to kernel IDs
2018-11-07 23:51:16 -06:00
psi: fix aggregation idle shut-off
2019-02-01 15:46:23 -08:00
psi: fix aggregation idle shut-off
2019-02-01 15:46:23 -08:00
07879c6a37