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dasharo_platform
2643 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
3a0562d733 |
Merge tag 'timers-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar: "Fix a PREEMPT_RT bug in the clocksource verification code that caused false positive warnings. Also fix a timer migration setup bug when new CPUs are added" * tag 'timers-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers/migration: Fix off-by-one root mis-connection clocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context |
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Frederic Weisbecker
|
868c9037df |
timers/migration: Fix off-by-one root mis-connection
Before attaching a new root to the old root, the children counter of the new root is checked to verify that only the upcoming CPU's top group have been connected to it. However since the recently added commit |
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Linus Torvalds
|
f286757b64 |
Merge tag 'timers-urgent-2025-02-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner: - Properly cast the input to secs_to_jiffies() to unsigned long as otherwise the result uses the data type of the input variable, which causes result range checks to fail if the input data type is signed and smaller than unsigned long. - Handle late armed hrtimers gracefully on CPU hotplug There are legitimate cases where a hrtimer is (re)armed on an outgoing CPU after the timers have been migrated away. This triggers warnings and caused people to implement horrible workarounds in RCU. But those workarounds are incomplete and do not cover e.g. the scheduler hrtimers. Stop this by force moving timer which are enqueued on the current CPU after timer migration to be queued on a remote online CPU. This allows to undo the workarounds in a seperate step. - Demote a warning level printk() to info level in the clocksource watchdog code as there is no point to emit a warning level message for a purely informational message. - Mark a helper function __always_inline and move it into the existing #ifdef block to avoid 'unused function' warnings from CLANG * tag 'timers-urgent-2025-02-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: jiffies: Cast to unsigned long in secs_to_jiffies() conversion clocksource: Use pr_info() for "Checking clocksource synchronization" message hrtimers: Force migrate away hrtimers queued after CPUHP_AP_HRTIMERS_DYING hrtimers: Mark is_migration_base() with __always_inline |
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Waiman Long
|
6bb05a3333 |
clocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context
The following bug report happened with a PREEMPT_RT kernel:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2012, name: kwatchdog
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
get_random_u32+0x4f/0x110
clocksource_verify_choose_cpus+0xab/0x1a0
clocksource_verify_percpu.part.0+0x6b/0x330
clocksource_watchdog_kthread+0x193/0x1a0
It is due to the fact that clocksource_verify_choose_cpus() is invoked with
preemption disabled. This function invokes get_random_u32() to obtain
random numbers for choosing CPUs. The batched_entropy_32 local lock and/or
the base_crng.lock spinlock in driver/char/random.c will be acquired during
the call. In PREEMPT_RT kernel, they are both sleeping locks and so cannot
be acquired in atomic context.
Fix this problem by using migrate_disable() to allow smp_processor_id() to
be reliably used without introducing atomic context. preempt_disable() is
then called after clocksource_verify_choose_cpus() but before the
clocksource measurement is being run to avoid introducing unexpected
latency.
Fixes:
|
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Joel Granados
|
1751f872cc |
treewide: const qualify ctl_tables where applicable
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.
Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit
|
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Waiman Long
|
1f566840a8 |
clocksource: Use pr_info() for "Checking clocksource synchronization" message
The "Checking clocksource synchronization" message is normally printed when clocksource_verify_percpu() is called for a given clocksource if both the CLOCK_SOURCE_UNSTABLE and CLOCK_SOURCE_VERIFY_PERCPU flags are set. It is an informational message and so pr_info() is the correct choice. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: John Stultz <jstultz@google.com> Link: https://lore.kernel.org/all/20250125015442.3740588-1-longman@redhat.com |
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Frederic Weisbecker
|
53dac34539 |
hrtimers: Force migrate away hrtimers queued after CPUHP_AP_HRTIMERS_DYING
hrtimers are migrated away from the dying CPU to any online target at the CPUHP_AP_HRTIMERS_DYING stage in order not to delay bandwidth timers handling tasks involved in the CPU hotplug forward progress. However wakeups can still be performed by the outgoing CPU after CPUHP_AP_HRTIMERS_DYING. Those can result again in bandwidth timers being armed. Depending on several considerations (crystal ball power management based election, earliest timer already enqueued, timer migration enabled or not), the target may eventually be the current CPU even if offline. If that happens, the timer is eventually ignored. The most notable example is RCU which had to deal with each and every of those wake-ups by deferring them to an online CPU, along with related workarounds: _ |
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Andy Shevchenko
|
27af31e449 |
hrtimers: Mark is_migration_base() with __always_inline
When is_migration_base() is unused, it prevents kernel builds
with clang, `make W=1` and CONFIG_WERROR=y:
kernel/time/hrtimer.c:156:20: error: unused function 'is_migration_base' [-Werror,-Wunused-function]
156 | static inline bool is_migration_base(struct hrtimer_clock_base *base)
| ^~~~~~~~~~~~~~~~~
Fix this by marking it with __always_inline.
[ tglx: Use __always_inline instead of __maybe_unused and move it into the
usage sites conditional ]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250116160745.243358-1-andriy.shevchenko@linux.intel.com
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Linus Torvalds
|
f200c315da |
Merge tag 'timers-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer and timekeeping updates from Thomas Gleixner: - Just boring cleanups, typo and comment fixes and trivial optimizations * tag 'timers-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers/migration: Simplify top level detection on group setup timers: Optimize get_timer_[this_]cpu_base() timekeeping: Remove unused ktime_get_fast_timestamps() timer/migration: Fix kernel-doc warnings for union tmigr_state tick/broadcast: Add kernel-doc for function parameters hrtimers: Update the return type of enqueue_hrtimer() clocksource/wdtest: Print time values for short udelay(1) posix-timers: Fix typo in __lock_timer() vdso: Correct typo in PAGE_SHIFT comment |
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Frederic Weisbecker
|
dcf6230555 |
timers/migration: Simplify top level detection on group setup
Having a single group on a given level is enough to know this is the top level, because a root has to have at least two children, unless that root is the only group and the children are actual CPUs. Simplify the test in tmigr_setup_groups() accordingly. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250114231507.21672-5-frederic@kernel.org |
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Koichiro Den
|
2f8dea1692 |
hrtimers: Handle CPU state correctly on hotplug
Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway
through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to
CPUHP_ONLINE:
Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set
to 1 throughout. However, during a CPU unplug operation, the tick and the
clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online
state, for instance CFS incorrectly assumes that the hrtick is already
active, and the chance of the clockevent device to transition to oneshot
mode is also lost forever for the CPU, unless it goes back to a lower state
than CPUHP_HRTIMERS_PREPARE once.
This round-trip reveals another issue; cpu_base.online is not set to 1
after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer().
Aside of that, the bulk of the per CPU state is not reset either, which
means there are dangling pointers in the worst case.
Address this by adding a corresponding startup() callback, which resets the
stale per CPU state and sets the online flag.
[ tglx: Make the new callback unconditionally available, remove the online
modification in the prepare() callback and clear the remaining
state in the starting callback instead of the prepare callback ]
Fixes:
|
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Frederic Weisbecker
|
922efd298b |
timers/migration: Annotate accesses to ignore flag
The group's ignore flag is: _ read under the group's lock (idle entry, remote expiry) _ turned on/off under the group's lock (idle entry, remote expiry) _ turned on locklessly on idle exit When idle entry or remote expiry clear the "ignore" flag of a group, the operation must be synchronized against other concurrent idle entry or remote expiry to make sure the related group timer is never missed. To enforce this synchronization, both "ignore" clear and read are performed under the group lock. On the contrary, whether idle entry or remote expiry manage to observe the "ignore" flag turned on by a CPU exiting idle is a matter of optimization. If that flag set is missed or cleared concurrently, the worst outcome is a migrator wasting time remotely handling a "ghost" timer. This is why the ignore flag can be set locklessly. Unfortunately, the related lockless accesses are bare and miss appropriate annotations. KCSAN rightfully complains: BUG: KCSAN: data-race in __tmigr_cpu_activate / print_report write to 0xffff88842fc28004 of 1 bytes by task 0 on cpu 0: __tmigr_cpu_activate tmigr_cpu_activate timer_clear_idle tick_nohz_restart_sched_tick tick_nohz_idle_exit do_idle cpu_startup_entry kernel_init do_initcalls clear_bss reserve_bios_regions common_startup_64 read to 0xffff88842fc28004 of 1 bytes by task 0 on cpu 1: print_report kcsan_report_known_origin kcsan_setup_watchpoint tmigr_next_groupevt tmigr_update_events tmigr_inactive_up __walk_groups+0x50/0x77 walk_groups __tmigr_cpu_deactivate tmigr_cpu_deactivate __get_next_timer_interrupt timer_base_try_to_set_idle tick_nohz_stop_tick tick_nohz_idle_stop_tick cpuidle_idle_call do_idle Although the relevant accesses could be marked as data_race(), the "ignore" flag being read several times within the same tmigr_update_events() function is confusing and error prone. Prefer reading it once in that function and make use of similar/paired accesses elsewhere with appropriate comments when necessary. Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250114231507.21672-4-frederic@kernel.org Closes: https://lore.kernel.org/oe-lkp/202501031612.62e0c498-lkp@intel.com |
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|
Frederic Weisbecker
|
de3ced72a7 |
timers/migration: Enforce group initialization visibility to tree walkers
Commit 2522c84db513 ("timers/migration: Fix another race between hotplug
and idle entry/exit") fixed yet another race between idle exit and CPU
hotplug up leading to a wrong "0" value migrator assigned to the top
level. However there is yet another situation that remains unhandled:
[GRP0:0]
migrator = TMIGR_NONE
active = NONE
groupmask = 1
/ \ \
0 1 2..7
idle idle idle
0) The system is fully idle.
[GRP0:0]
migrator = CPU 0
active = CPU 0
groupmask = 1
/ \ \
0 1 2..7
active idle idle
1) CPU 0 is activating. It has done the cmpxchg on the top's ->migr_state
but it hasn't yet returned to __walk_groups().
[GRP0:0]
migrator = CPU 0
active = CPU 0, CPU 1
groupmask = 1
/ \ \
0 1 2..7
active active idle
2) CPU 1 is activating. CPU 0 stays the migrator (still stuck in
__walk_groups(), delayed by #VMEXIT for example).
[GRP1:0]
migrator = TMIGR_NONE
active = NONE
groupmask = 1
/ \
[GRP0:0] [GRP0:1]
migrator = CPU 0 migrator = TMIGR_NONE
active = CPU 0, CPU1 active = NONE
groupmask = 1 groupmask = 2
/ \ \
0 1 2..7 8
active active idle !online
3) CPU 8 is preparing to boot. CPUHP_TMIGR_PREPARE is being ran by CPU 1
which has created the GRP0:1 and the new top GRP1:0 connected to GRP0:1
and GRP0:0. CPU 1 hasn't yet propagated its activation up to GRP1:0.
[GRP1:0]
migrator = GRP0:0
active = GRP0:0
groupmask = 1
/ \
[GRP0:0] [GRP0:1]
migrator = CPU 0 migrator = TMIGR_NONE
active = CPU 0, CPU1 active = NONE
groupmask = 1 groupmask = 2
/ \ \
0 1 2..7 8
active active idle !online
4) CPU 0 finally resumed after its #VMEXIT. It's in __walk_groups()
returning from tmigr_cpu_active(). The new top GRP1:0 is visible and
fetched and the pre-initialized groupmask of GRP0:0 is also visible.
As a result tmigr_active_up() is called to GRP1:0 with GRP0:0 as active
and migrator. CPU 0 is returning to __walk_groups() but suffers again
a #VMEXIT.
[GRP1:0]
migrator = GRP0:0
active = GRP0:0
groupmask = 1
/ \
[GRP0:0] [GRP0:1]
migrator = CPU 0 migrator = TMIGR_NONE
active = CPU 0, CPU1 active = NONE
groupmask = 1 groupmask = 2
/ \ \
0 1 2..7 8
active active idle !online
5) CPU 1 propagates its activation of GRP0:0 to GRP1:0. This has no
effect since CPU 0 did it already.
[GRP1:0]
migrator = GRP0:0
active = GRP0:0, GRP0:1
groupmask = 1
/ \
[GRP0:0] [GRP0:1]
migrator = CPU 0 migrator = CPU 8
active = CPU 0, CPU1 active = CPU 8
groupmask = 1 groupmask = 2
/ \ \ \
0 1 2..7 8
active active idle active
6) CPU 1 links CPU 8 to its group. CPU 8 boots and goes through
CPUHP_AP_TMIGR_ONLINE which propagates activation.
[GRP2:0]
migrator = TMIGR_NONE
active = NONE
groupmask = 1
/ \
[GRP1:0] [GRP1:1]
migrator = GRP0:0 migrator = TMIGR_NONE
active = GRP0:0, GRP0:1 active = NONE
groupmask = 1 groupmask = 2
/ \
[GRP0:0] [GRP0:1] [GRP0:2]
migrator = CPU 0 migrator = CPU 8 migrator = TMIGR_NONE
active = CPU 0, CPU1 active = CPU 8 active = NONE
groupmask = 1 groupmask = 2 groupmask = 0
/ \ \ \
0 1 2..7 8 64
active active idle active !online
7) CPU 64 is booting. CPUHP_TMIGR_PREPARE is being ran by CPU 1
which has created the GRP1:1, GRP0:2 and the new top GRP2:0 connected to
GRP1:1 and GRP1:0. CPU 1 hasn't yet propagated its activation up to
GRP2:0.
[GRP2:0]
migrator = 0 (!!!)
active = NONE
groupmask = 1
/ \
[GRP1:0] [GRP1:1]
migrator = GRP0:0 migrator = TMIGR_NONE
active = GRP0:0, GRP0:1 active = NONE
groupmask = 1 groupmask = 2
/ \
[GRP0:0] [GRP0:1] [GRP0:2]
migrator = CPU 0 migrator = CPU 8 migrator = TMIGR_NONE
active = CPU 0, CPU1 active = CPU 8 active = NONE
groupmask = 1 groupmask = 2 groupmask = 0
/ \ \ \
0 1 2..7 8 64
active active idle active !online
8) CPU 0 finally resumed after its #VMEXIT. It's in __walk_groups()
returning from tmigr_cpu_active(). The new top GRP2:0 is visible and
fetched but the pre-initialized groupmask of GRP1:0 is not because no
ordering made its initialization visible. As a result tmigr_active_up()
may be called to GRP2:0 with a "0" child's groumask. Leaving the timers
ignored for ever when the system is fully idle.
The race is highly theoretical and perhaps impossible in practice but
the groupmask of the child is not the only concern here as the whole
initialization of the child is not guaranteed to be visible to any
tree walker racing against hotplug (idle entry/exit, remote handling,
etc...). Although the current code layout seem to be resilient to such
hazards, this doesn't tell much about the future.
Fix this with enforcing address dependency between group initialization
and the write/read to the group's parent's pointer. Fortunately that
doesn't involve any barrier addition in the fast paths.
Fixes:
|
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Frederic Weisbecker
|
b729cc1ec2 |
timers/migration: Fix another race between hotplug and idle entry/exit
Commit |
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Zhongqiu Han
|
3ec955713d |
timers: Optimize get_timer_[this_]cpu_base()
If a timer is deferrable and NO_HZ_COMMON is enabled, get_timer_cpu_base() and get_timer_this_cpu_base() invoke per_cpu_ptr() and this_cpu_ptr() twice. While this seems to be cheap, get_timer_cpu_base() can be called in a loop in lock_timer_base(). Optimize the functions by updating the base index for deferrable timers and retrieving the actual base pointer once. In both cases the resulting assembly code of those helpers becomes smaller, which results in a ~30% execution time reduction for a lock_timer_base() micro bench mark. Signed-off-by: Zhongqiu Han <quic_zhonhan@quicinc.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241231150115.1978342-1-quic_zhonhan@quicinc.com |
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Dr. David Alan Gilbert
|
2d2a46cf23 |
timekeeping: Remove unused ktime_get_fast_timestamps()
ktime_get_fast_timestamps() was added in 2020 by commit
|
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Randy Dunlap
|
4477b06014 |
timer/migration: Fix kernel-doc warnings for union tmigr_state
Use the correct kernel-doc notation for nested structs/unions to eliminate warnings: timer_migration.h:119: warning: Incorrect use of kernel-doc format: * struct - split state of tmigr_group timer_migration.h:134: warning: Function parameter or struct member 'active' not described in 'tmigr_state' timer_migration.h:134: warning: Function parameter or struct member 'migrator' not described in 'tmigr_state' timer_migration.h:134: warning: Function parameter or struct member 'seq' not described in 'tmigr_state' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250111063156.910903-1-rdunlap@infradead.org |
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Randy Dunlap
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4903e1ba79 |
tick/broadcast: Add kernel-doc for function parameters
Add kernel-doc comments for two parameters to eliminate kernel-doc warnings: tick-broadcast.c:1026: warning: Function parameter or struct member 'bc' not described in 'tick_broadcast_setup_oneshot' tick-broadcast.c:1026: warning: Function parameter or struct member 'from_periodic' not described in 'tick_broadcast_setup_oneshot' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250111063148.910887-1-rdunlap@infradead.org |
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Richard Clark
|
da7100d3bf |
hrtimers: Update the return type of enqueue_hrtimer()
The return type should be 'bool' instead of 'int' according to the calling context in the kernel, and its internal implementation, i.e. : return timerqueue_add(); which is a bool-return function. [ tglx: Adjust function arguments ] Signed-off-by: Richard Clark <richard.xnu.clark@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/Z2ppT7me13dtxm1a@MBC02GN1V4Q05P |
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Paul E. McKenney
|
776b194116 |
clocksource/wdtest: Print time values for short udelay(1)
When a pair of clocksource reads separated by a udelay(1) claim less than a full microsecond of elapsed time, print the measured delay as part of the splat. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/717a2ddf-a80f-490b-aa3a-4e4b74fa56ca@paulmck-laptop |
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Zhu Jun
|
9f38e83a88 |
posix-timers: Fix typo in __lock_timer()
The word 'accross' is wrong, so fix it. Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241204080907.11989-1-zhujun2@cmss.chinamobile.com |
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Thomas Gleixner
|
76031d9536 |
clocksource: Make negative motion detection more robust
Guenter reported boot stalls on a emulated ARM 32-bit platform, which has a
24-bit wide clocksource.
It turns out that the calculated maximal idle time, which limits idle
sleeps to prevent clocksource wrap arounds, is close to the point where the
negative motion detection triggers.
max_idle_ns: 597268854 ns
negative motion tripping point: 671088640 ns
If the idle wakeup is delayed beyond that point, the clocksource
advances far enough to trigger the negative motion detection. This
prevents the clock to advance and in the worst case the system stalls
completely if the consecutive sleeps based on the stale clock are
delayed as well.
Cure this by calculating a more robust cut-off value for negative motion,
which covers 87.5% of the actual clocksource counter width. Compare the
delta against this value to catch negative motion. This is specifically for
clock sources with a small counter width as their wrap around time is close
to the half counter width. For clock sources with wide counters this is not
a problem because the maximum idle time is far from the half counter width
due to the math overflow protection constraints.
For the case at hand this results in a tripping point of 1174405120ns.
Note, that this cannot prevent issues when the delay exceeds the 87.5%
margin, but that's not different from the previous unchecked version which
allowed arbitrary time jumps.
Systems with small counter width are prone to invalid results, but this
problem is unlikely to be seen on real hardware. If such a system
completely stalls for more than half a second, then there are other more
urgent problems than the counter wrapping around.
Fixes:
|
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Marcelo Dalmas
|
f5807b0606 |
ntp: Remove invalid cast in time offset math
Due to an unsigned cast, adjtimex() returns the wrong offest when using
ADJ_MICRO and the offset is negative. In this case a small negative offset
returns approximately 4.29 seconds (~ 2^32/1000 milliseconds) due to the
unsigned cast of the negative offset.
This cast was added when the kernel internal struct timex was changed to
use type long long for the time offset value to address the problem of a
64bit/32bit division on 32bit systems.
The correct cast would have been (s32), which is correct as time_offset can
only be in the range of [INT_MIN..INT_MAX] because the shift constant used
for calculating it is 32. But that's non-obvious.
Remove the cast and use div_s64() to cure the issue.
[ tglx: Fix white space damage, use div_s64() and amend the change log ]
Fixes:
|
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|
Linus Torvalds
|
bf9aa14fc5 |
Merge tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"A rather large update for timekeeping and timers:
- The final step to get rid of auto-rearming posix-timers
posix-timers are currently auto-rearmed by the kernel when the
signal of the timer is ignored so that the timer signal can be
delivered once the corresponding signal is unignored.
This requires to throttle the timer to prevent a DoS by small
intervals and keeps the system pointlessly out of low power states
for no value. This is a long standing non-trivial problem due to
the lock order of posix-timer lock and the sighand lock along with
life time issues as the timer and the sigqueue have different life
time rules.
Cure this by:
- Embedding the sigqueue into the timer struct to have the same
life time rules. Aside of that this also avoids the lookup of
the timer in the signal delivery and rearm path as it's just a
always valid container_of() now.
- Queuing ignored timer signals onto a seperate ignored list.
- Moving queued timer signals onto the ignored list when the
signal is switched to SIG_IGN before it could be delivered.
- Walking the ignored list when SIG_IGN is lifted and requeue the
signals to the actual signal lists. This allows the signal
delivery code to rearm the timer.
This also required to consolidate the signal delivery rules so they
are consistent across all situations. With that all self test
scenarios finally succeed.
- Core infrastructure for VFS multigrain timestamping
This is required to allow the kernel to use coarse grained time
stamps by default and switch to fine grained time stamps when inode
attributes are actively observed via getattr().
These changes have been provided to the VFS tree as well, so that
the VFS specific infrastructure could be built on top.
- Cleanup and consolidation of the sleep() infrastructure
- Move all sleep and timeout functions into one file
- Rework udelay() and ndelay() into proper documented inline
functions and replace the hardcoded magic numbers by proper
defines.
- Rework the fsleep() implementation to take the reality of the
timer wheel granularity on different HZ values into account.
Right now the boundaries are hard coded time ranges which fail
to provide the requested accuracy on different HZ settings.
- Update documentation for all sleep/timeout related functions
and fix up stale documentation links all over the place
- Fixup a few usage sites
- Rework of timekeeping and adjtimex(2) to prepare for multiple PTP
clocks
A system can have multiple PTP clocks which are participating in
seperate and independent PTP clock domains. So far the kernel only
considers the PTP clock which is based on CLOCK TAI relevant as
that's the clock which drives the timekeeping adjustments via the
various user space daemons through adjtimex(2).
The non TAI based clock domains are accessible via the file
descriptor based posix clocks, but their usability is very limited.
They can't be accessed fast as they always go all the way out to
the hardware and they cannot be utilized in the kernel itself.
As Time Sensitive Networking (TSN) gains traction it is required to
provide fast user and kernel space access to these clocks.
The approach taken is to utilize the timekeeping and adjtimex(2)
infrastructure to provide this access in a similar way how the
kernel provides access to clock MONOTONIC, REALTIME etc.
Instead of creating a duplicated infrastructure this rework
converts timekeeping and adjtimex(2) into generic functionality
which operates on pointers to data structures instead of using
static variables.
This allows to provide time accessors and adjtimex(2) functionality
for the independent PTP clocks in a subsequent step.
- Consolidate hrtimer initialization
hrtimers are set up by initializing the data structure and then
seperately setting the callback function for historical reasons.
That's an extra unnecessary step and makes Rust support less
straight forward than it should be.
Provide a new set of hrtimer_setup*() functions and convert the
core code and a few usage sites of the less frequently used
interfaces over.
The bulk of the htimer_init() to hrtimer_setup() conversion is
already prepared and scheduled for the next merge window.
- Drivers:
- Ensure that the global timekeeping clocksource is utilizing the
cluster 0 timer on MIPS multi-cluster systems.
Otherwise CPUs on different clusters use their cluster specific
clocksource which is not guaranteed to be synchronized with
other clusters.
- Mostly boring cleanups, fixes, improvements and code movement"
* tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
posix-timers: Fix spurious warning on double enqueue versus do_exit()
clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
clocksource/drivers/gpx: Remove redundant casts
clocksource/drivers/timer-ti-dm: Fix child node refcount handling
dt-bindings: timer: actions,owl-timer: convert to YAML
clocksource/drivers/ralink: Add Ralink System Tick Counter driver
clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
clocksource/drivers:sp804: Make user selectable
clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
hrtimers: Delete hrtimer_init_on_stack()
alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack()
io_uring: Switch to use hrtimer_setup_on_stack()
sched/idle: Switch to use hrtimer_setup_on_stack()
hrtimers: Delete hrtimer_init_sleeper_on_stack()
wait: Switch to use hrtimer_setup_sleeper_on_stack()
timers: Switch to use hrtimer_setup_sleeper_on_stack()
net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack()
futex: Switch to use hrtimer_setup_sleeper_on_stack()
fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()
...
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Linus Torvalds
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0352387523 |
Merge tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull vdso data page handling updates from Thomas Gleixner:
"First steps of consolidating the VDSO data page handling.
The VDSO data page handling is architecture specific for historical
reasons, but there is no real technical reason to do so.
Aside of that VDSO data has become a dump ground for various
mechanisms and fail to provide a clear separation of the
functionalities.
Clean this up by:
- consolidating the VDSO page data by getting rid of architecture
specific warts especially in x86 and PowerPC.
- removing the last includes of header files which are pulling in
other headers outside of the VDSO namespace.
- seperating timekeeping and other VDSO data accordingly.
Further consolidation of the VDSO page handling is done in subsequent
changes scheduled for the next merge window.
This also lays the ground for expanding the VDSO time getters for
independent PTP clocks in a generic way without making every
architecture add support seperately"
* tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
x86/vdso: Add missing brackets in switch case
vdso: Rename struct arch_vdso_data to arch_vdso_time_data
powerpc: Split systemcfg struct definitions out from vdso
powerpc: Split systemcfg data out of vdso data page
powerpc: Add kconfig option for the systemcfg page
powerpc/pseries/lparcfg: Use num_possible_cpus() for potential processors
powerpc/pseries/lparcfg: Fix printing of system_active_processors
powerpc/procfs: Propagate error of remap_pfn_range()
powerpc/vdso: Remove offset comment from 32bit vdso_arch_data
x86/vdso: Split virtual clock pages into dedicated mapping
x86/vdso: Delete vvar.h
x86/vdso: Access vdso data without vvar.h
x86/vdso: Move the rng offset to vsyscall.h
x86/vdso: Access rng vdso data without vvar.h
x86/vdso: Access timens vdso data without vvar.h
x86/vdso: Allocate vvar page from C code
x86/vdso: Access rng data from kernel without vvar
x86/vdso: Place vdso_data at beginning of vvar page
x86/vdso: Use __arch_get_vdso_data() to access vdso data
x86/mm/mmap: Remove arch_vma_name()
...
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