On Fri, May 08, 2020 at 08:11:55PM -0700, Bart Van Assche wrote:
> On 2020-05-08 19:09, Ming Lei wrote:
> > On Fri, May 08, 2020 at 04:26:17PM -0700, Bart Van Assche wrote:
> >> On 2020-05-04 19:09, Ming Lei wrote:
> >>> @@ -391,6 +393,7 @@ struct blk_mq_ops {
> >>> enum {
> >>> BLK_MQ_F_SHOULD_MERGE = 1 << 0,
> >>> BLK_MQ_F_TAG_SHARED = 1 << 1,
> >>> + BLK_MQ_F_NO_MANAGED_IRQ = 1 << 2,
> >>> BLK_MQ_F_BLOCKING = 1 << 5,
> >>> BLK_MQ_F_NO_SCHED = 1 << 6,
> >>> BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
> >>> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> >>> index 77d70b633531..24b3a77810b6 100644
> >>> --- a/include/linux/cpuhotplug.h
> >>> +++ b/include/linux/cpuhotplug.h
> >>> @@ -152,6 +152,7 @@ enum cpuhp_state {
> >>> CPUHP_AP_SMPBOOT_THREADS,
> >>> CPUHP_AP_X86_VDSO_VMA_ONLINE,
> >>> CPUHP_AP_IRQ_AFFINITY_ONLINE,
> >>> + CPUHP_AP_BLK_MQ_ONLINE,
> >>> CPUHP_AP_ARM_MVEBU_SYNC_CLOCKS,
> >>> CPUHP_AP_X86_INTEL_EPB_ONLINE,
> >>> CPUHP_AP_PERF_ONLINE,
> >>
> >> Wouldn't BLK_MQ_F_NO_IRQ be a better name than BLK_MQ_F_NO_MANAGED_IRQ?
> >
> > No, what this patchset tries to do is to address request timeout or hang
> > issue in case that managed irq is applied in blk-mq driver.
>
> What is a managed IRQ? The following query did not produce a useful answer:
>
> $ git grep -nHi managed.irq
[ming@T590 linux]$ git grep -n MANAGED ./kernel/irq
kernel/irq/chip.c:188: IRQ_STARTUP_MANAGED,
kernel/irq/chip.c:226: return IRQ_STARTUP_MANAGED;
kernel/irq/chip.c:271: case IRQ_STARTUP_MANAGED:
kernel/irq/cpuhotplug.c:179: if (!housekeeping_enabled(HK_FLAG_MANAGED_IRQ))
kernel/irq/cpuhotplug.c:182: hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
kernel/irq/debugfs.c:114: BIT_MASK_DESCR(IRQD_AFFINITY_MANAGED),
kernel/irq/debugfs.c:115: BIT_MASK_DESCR(IRQD_MANAGED_SHUTDOWN),
kernel/irq/internals.h:215: __irqd_to_state(d) |= IRQD_MANAGED_SHUTDOWN;
kernel/irq/internals.h:220: __irqd_to_state(d) &= ~IRQD_MANAGED_SHUTDOWN;
kernel/irq/irqdesc.c:487: flags = IRQD_AFFINITY_MANAGED |
kernel/irq/irqdesc.c:488: IRQD_MANAGED_SHUTDOWN;
kernel/irq/manage.c:170: * AFFINITY_MANAGED flag.
kernel/irq/manage.c:241: housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
kernel/irq/manage.c:247: hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
The exact name should be AFFINITY_MANAGED, however the name of managed
irq has been used in commit log and isolation cpus code for a bit long.
OK, I will add comment on BLK_MQ_F_NO_MANAGED_IRQ a bit in next version.
Thanks,
Ming
