linux/kernel
Ming Lei 11ea68f553 genirq, sched/isolation: Isolate from handling managed interrupts
The affinity of managed interrupts is completely handled in the kernel and
cannot be changed via the /proc/irq/* interfaces from user space. As the
kernel tries to spread out interrupts evenly accross CPUs on x86 to prevent
vector exhaustion, it can happen that a managed interrupt whose affinity
mask contains both isolated and housekeeping CPUs is routed to an isolated
CPU. As a consequence IO submitted on a housekeeping CPU causes interrupts
on the isolated CPU.

Add a new sub-parameter 'managed_irq' for 'isolcpus' and the corresponding
logic in the interrupt affinity selection code.

The subparameter indicates to the interrupt affinity selection logic that
it should try to avoid the above scenario.

This isolation is best effort and only effective if the automatically
assigned interrupt mask of a device queue contains isolated and
housekeeping CPUs. If housekeeping CPUs are online then such interrupts are
directed to the housekeeping CPU so that IO submitted on the housekeeping
CPU cannot disturb the isolated CPU.

If a queue's affinity mask contains only isolated CPUs then this parameter
has no effect on the interrupt routing decision, though interrupts are only
happening when tasks running on those isolated CPUs submit IO. IO submitted
on housekeeping CPUs has no influence on those queues.

If the affinity mask contains both housekeeping and isolated CPUs, but none
of the contained housekeeping CPUs is online, then the interrupt is also
routed to an isolated CPU. Interrupts are only delivered when one of the
isolated CPUs in the affinity mask submits IO. If one of the contained
housekeeping CPUs comes online, the CPU hotplug logic migrates the
interrupt automatically back to the upcoming housekeeping CPU. Depending on
the type of interrupt controller, this can require that at least one
interrupt is delivered to the isolated CPU in order to complete the
migration.

[ tglx: Removed unused parameter, added and edited comments/documentation
  	and rephrased the changelog so it contains more details. ]

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200120091625.17912-1-ming.lei@redhat.com
2020-01-22 16:29:49 +01:00
..
bpf bpf: Fix precision tracking for unbounded scalars 2019-12-22 17:21:10 -08:00
cgroup Merge branch 'for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2019-11-25 19:23:46 -08:00
configs
debug kdb: Tweak escape handling for vi users 2019-10-28 12:08:29 +00:00
dma lib/genalloc.c: rename addr_in_gen_pool to gen_pool_has_addr 2019-12-04 19:44:13 -08:00
events perf/core: Add SRCU annotation for pmus list walk 2019-12-17 13:32:46 +01:00
gcov um: Enable CONFIG_CONSTRUCTORS 2019-09-15 21:37:13 +02:00
irq genirq, sched/isolation: Isolate from handling managed interrupts 2020-01-22 16:29:49 +01:00
livepatch New tracing features: 2019-11-27 11:42:01 -08:00
locking Revert "locking/mutex: Complain upon mutex API misuse in IRQ contexts" 2019-12-11 00:27:43 +01:00
power Additional power management updates for 5.5-rc1 2019-12-04 10:48:09 -08:00
printk Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-12-03 09:29:50 -08:00
rcu Merge branches 'doc.2019.10.29a', 'fixes.2019.10.30a', 'nohz.2019.10.28a', 'replace.2019.10.30a', 'torture.2019.10.05a' and 'lkmm.2019.10.05a' into HEAD 2019-10-30 08:47:13 -07:00
sched genirq, sched/isolation: Isolate from handling managed interrupts 2020-01-22 16:29:49 +01:00
time ptp: fix the race between the release of ptp_clock and cdev 2019-12-30 20:19:27 -08:00
trace tracing: Fix endianness bug in histogram trigger 2019-12-21 16:08:59 -05:00
.gitignore Provide in-kernel headers to make extending kernel easier 2019-04-29 16:48:03 +02:00
acct.c acct_on(): don't mess with freeze protection 2019-04-04 21:04:13 -04:00
async.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
audit_fsnotify.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
audit_tree.c fsnotify: switch send_to_group() and ->handle_event to const struct qstr * 2019-04-26 13:51:03 -04:00
audit_watch.c audit_get_nd(): don't unlock parent too early 2019-11-10 11:56:55 -05:00
audit.c audit: remove redundant condition check in kauditd_thread() 2019-10-25 11:48:14 -04:00
audit.h audit/stable-5.3 PR 20190702 2019-07-08 18:55:42 -07:00
auditfilter.c audit/stable-5.3 PR 20190702 2019-07-08 18:55:42 -07:00
auditsc.c Revert "bpf: Emit audit messages upon successful prog load and unload" 2019-11-23 09:56:02 -08:00
backtracetest.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
bounds.c
capability.c
compat.c y2038: itimer: compat handling to itimer.c 2019-11-15 14:38:30 +01:00
configs.c kernel/configs: Replace GPL boilerplate code with SPDX identifier 2019-07-30 18:34:15 +02:00
context_tracking.c context_tracking: Rename context_tracking_is_enabled() => context_tracking_enabled() 2019-10-29 10:01:12 +01:00
cpu_pm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
cpu.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 16:02:40 -08:00
crash_core.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230 2019-06-19 17:09:06 +02:00
crash_dump.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
cred.c memcg: account security cred as well to kmemcg 2020-01-04 13:55:09 -08:00
delayacct.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 25 2019-05-21 11:52:39 +02:00
dma.c
elfcore.c kernel/elfcore.c: include proper prototypes 2019-09-25 17:51:39 -07:00
exec_domain.c
exit.c for-linus-2020-01-03 2020-01-03 11:17:14 -08:00
extable.c bpf: Add support for BTF pointers to x86 JIT 2019-10-17 16:44:36 +02:00
fail_function.c fail_function: no need to check return value of debugfs_create functions 2019-06-03 15:49:06 +02:00
fork.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-12-03 12:20:25 -08:00
freezer.c Revert "libata, freezer: avoid block device removal while system is frozen" 2019-10-06 09:11:37 -06:00
futex.c futex: Prevent exit livelock 2019-11-20 09:40:38 +01:00
gen_kheaders.sh kheaders: explain why include/config/autoconf.h is excluded from md5sum 2019-11-11 20:10:01 +09:00
groups.c
hung_task.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
iomem.c mm/nvdimm: add is_ioremap_addr and use that to check ioremap address 2019-07-12 11:05:40 -07:00
irq_work.c irq_work: Fix IRQ_WORK_BUSY bit clearing 2019-11-15 10:48:37 +01:00
jump_label.c jump_label: Don't warn on __exit jump entries 2019-08-29 15:10:10 +01:00
kallsyms.c kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol 2019-08-27 16:19:56 +01:00
kcmp.c
Kconfig.freezer treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.hz treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.locks treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.preempt sched/Kconfig: Fix spelling mistake in user-visible help text 2019-11-12 11:35:32 +01:00
kcov.c kcov: remote coverage support 2019-12-04 19:44:14 -08:00
kexec_core.c kexec: bail out upon SIGKILL when allocating memory. 2019-09-25 17:51:40 -07:00
kexec_elf.c kexec_elf: support 32 bit ELF files 2019-09-06 23:58:44 +02:00
kexec_file.c kexec: Fix pointer-to-int-cast warnings 2019-11-01 21:42:58 +01:00
kexec_internal.h
kexec.c kexec_load: Disable at runtime if the kernel is locked down 2019-08-19 21:54:15 -07:00
kheaders.c kheaders: Move from proc to sysfs 2019-05-24 20:16:01 +02:00
kmod.c
kprobes.c Tracing updates: 2019-09-20 11:19:48 -07:00
ksysfs.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 170 2019-05-30 11:26:39 -07:00
kthread.c kthread: make __kthread_queue_delayed_work static 2019-10-16 09:20:58 -07:00
latencytop.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
Makefile Kbuild updates for v5.5 2019-12-02 17:35:04 -08:00
module_signature.c MODSIGN: Export module signature definitions 2019-08-05 18:39:56 -04:00
module_signing.c MODSIGN: Export module signature definitions 2019-08-05 18:39:56 -04:00
module-internal.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
module.c This contains 3 changes: 2019-12-11 12:22:38 -08:00
notifier.c kernel/notifier.c: remove blocking_notifier_chain_cond_register() 2019-12-04 19:44:12 -08:00
nsproxy.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
padata.c padata: remove cpu_index from the parallel_queue 2019-09-13 21:15:41 +10:00
panic.c locking/refcount: Remove unused 'refcount_error_report()' function 2019-11-25 09:15:42 +01:00
params.c lockdown: Lock down module params that specify hardware parameters (eg. ioport) 2019-08-19 21:54:16 -07:00
pid_namespace.c fork: extend clone3() to support setting a PID 2019-11-15 23:49:22 +01:00
pid.c fork: extend clone3() to support setting a PID 2019-11-15 23:49:22 +01:00
profile.c kernel/profile.c: use cpumask_available to check for NULL cpumask 2019-12-04 19:44:12 -08:00
ptrace.c ptrace: add PTRACE_GET_SYSCALL_INFO request 2019-07-16 19:23:24 -07:00
range.c
reboot.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
relay.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-03-12 13:27:20 -07:00
resource.c mm/memory_hotplug.c: use PFN_UP / PFN_DOWN in walk_system_ram_range() 2019-09-24 15:54:09 -07:00
rseq.c signal: Remove task parameter from force_sig 2019-05-27 09:36:28 -05:00
seccomp.c seccomp: Check that seccomp_notif is zeroed out by the user 2020-01-02 13:03:45 -08:00
signal.c cgroup: freezer: call cgroup_enter_frozen() with preemption disabled in ptrace_stop() 2019-10-11 08:39:57 -07:00
smp.c smp: Warn on function calls from softirq context 2019-07-20 11:27:16 +02:00
smpboot.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
smpboot.h
softirq.c Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 11:01:13 -07:00
stackleak.c
stacktrace.c stacktrace: Get rid of unneeded '!!' pattern 2019-11-11 10:30:59 +01:00
stop_machine.c Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2019-10-31 09:33:19 +01:00
sys_ni.c y2038: allow disabling time32 system calls 2019-11-15 14:38:30 +01:00
sys.c kernel/sys.c: avoid copying possible padding bytes in copy_to_user 2019-12-04 19:44:12 -08:00
sysctl_binary.c sysctl: Remove the sysctl system call 2019-11-26 13:03:56 -06:00
sysctl-test.c kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() 2019-09-30 17:35:01 -06:00
sysctl.c kernel: sysctl: make drop_caches write-only 2019-12-01 12:59:07 -08:00
task_work.c
taskstats.c taskstats: fix data-race 2019-12-04 15:18:39 +01:00
test_kprobes.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 25 2019-05-21 11:52:39 +02:00
torture.c torture: Remove exporting of internal functions 2019-08-01 14:30:22 -07:00
tracepoint.c The main changes in this release include: 2019-07-18 11:51:00 -07:00
tsacct.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
ucount.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
uid16.c
uid16.h
umh.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
up.c smp: Remove smp_call_function() and on_each_cpu() return values 2019-06-23 14:26:26 +02:00
user_namespace.c Keyrings namespacing 2019-07-08 19:36:47 -07:00
user-return-notifier.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
user.c Keyrings namespacing 2019-07-08 19:36:47 -07:00
utsname_sysctl.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
utsname.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
watchdog_hld.c kernel/watchdog_hld.c: hard lockup message should end with a newline 2019-04-19 09:46:05 -07:00
watchdog.c watchdog: Mark watchdog_hrtimer to expire in hard interrupt context 2019-08-01 20:51:20 +02:00
workqueue_internal.h sched/core, workqueues: Distangle worker accounting from rq lock 2019-04-16 16:55:15 +02:00
workqueue.c workqueue: Use pr_warn instead of pr_warning 2019-12-06 09:59:30 +01:00