From: Ming Lei <ming.lei@redhat.com>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, John Garry <john.garry@huawei.com>,
Hannes Reinecke <hare@suse.com>, Christoph Hellwig <hch@lst.de>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH V10 06/11] blk-mq: prepare for draining IO when hctx's all CPUs are offline
Date: Sat, 9 May 2020 11:56:09 +0800 [thread overview]
Message-ID: <20200509035609.GF1392681@T590> (raw)
In-Reply-To: <d59e0c74-981d-6ed4-e80d-09b0cd4c17db@acm.org>
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
next prev parent reply other threads:[~2020-05-09 3:56 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 2:09 [PATCH V10 00/11] blk-mq: improvement CPU hotplug Ming Lei
2020-05-05 2:09 ` [PATCH V10 01/11] block: clone nr_integrity_segments and write_hint in blk_rq_prep_clone Ming Lei
2020-05-05 2:09 ` [PATCH V10 02/11] block: add helper for copying request Ming Lei
2020-05-05 2:09 ` [PATCH V10 03/11] blk-mq: mark blk_mq_get_driver_tag as static Ming Lei
2020-05-05 2:09 ` [PATCH V10 04/11] blk-mq: assign rq->tag in blk_mq_get_driver_tag Ming Lei
2020-05-05 2:09 ` [PATCH V10 05/11] blk-mq: support rq filter callback when iterating rqs Ming Lei
2020-05-08 23:32 ` Bart Van Assche
2020-05-09 0:18 ` Bart Van Assche
2020-05-09 2:05 ` Ming Lei
2020-05-09 3:08 ` Bart Van Assche
2020-05-09 3:52 ` Ming Lei
2020-05-05 2:09 ` [PATCH V10 06/11] blk-mq: prepare for draining IO when hctx's all CPUs are offline Ming Lei
2020-05-05 6:14 ` Hannes Reinecke
2020-05-08 23:26 ` Bart Van Assche
2020-05-09 2:09 ` Ming Lei
2020-05-09 3:11 ` Bart Van Assche
2020-05-09 3:56 ` Ming Lei [this message]
2020-05-05 2:09 ` [PATCH V10 07/11] blk-mq: stop to handle IO and drain IO before hctx becomes inactive Ming Lei
2020-05-08 23:39 ` Bart Van Assche
2020-05-09 2:20 ` Ming Lei
2020-05-09 3:24 ` Bart Van Assche
2020-05-09 4:10 ` Ming Lei
2020-05-09 14:18 ` Bart Van Assche
2020-05-11 1:45 ` Ming Lei
2020-05-11 3:20 ` Bart Van Assche
2020-05-11 3:48 ` Ming Lei
2020-05-11 20:56 ` Bart Van Assche
2020-05-12 1:25 ` Ming Lei
2020-05-05 2:09 ` [PATCH V10 08/11] block: add blk_end_flush_machinery Ming Lei
2020-05-05 2:09 ` [PATCH V10 09/11] blk-mq: add blk_mq_hctx_handle_dead_cpu for handling cpu dead Ming Lei
2020-05-05 2:09 ` [PATCH V10 10/11] blk-mq: re-submit IO in case that hctx is inactive Ming Lei
2020-05-05 2:09 ` [PATCH V10 11/11] block: deactivate hctx when the hctx is actually inactive Ming Lei
2020-05-09 14:07 ` Bart Van Assche
2020-05-11 2:11 ` Ming Lei
2020-05-11 3:30 ` Bart Van Assche
2020-05-11 4:08 ` Ming Lei
2020-05-11 20:52 ` Bart Van Assche
2020-05-12 1:43 ` Ming Lei
2020-05-12 2:08 ` Ming Lei
2020-05-08 21:49 ` [PATCH V10 00/11] blk-mq: improvement CPU hotplug Ming Lei
2020-05-09 3:17 ` Jens Axboe
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