From: James Morse <james.morse@arm.com>
To: Reinette Chatre <reinette.chatre@intel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
H Peter Anvin <hpa@zytor.com>, Babu Moger <Babu.Moger@amd.com>,
shameerali.kolothum.thodi@huawei.com,
D Scott Phillips OS <scott@os.amperecomputing.com>,
carl@os.amperecomputing.com, lcherian@marvell.com,
bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com,
xingxin.hx@openanolis.org, baolin.wang@linux.alibaba.com,
Jamie Iles <quic_jiles@quicinc.com>,
Xin Hao <xhao@linux.alibaba.com>,
peternewman@google.com, dfustini@baylibre.com
Subject: Re: [PATCH v5 21/24] x86/resctrl: Allow overflow/limbo handlers to be scheduled on any-but cpu
Date: Thu, 24 Aug 2023 17:57:51 +0100 [thread overview]
Message-ID: <9fca4876-01f4-6a84-2dc6-d92458d3b72c@arm.com> (raw)
In-Reply-To: <b8103525-83d7-b8f1-105a-178625b89da4@intel.com>
Hi Reinette,
On 09/08/2023 23:38, Reinette Chatre wrote:
> On 7/28/2023 9:42 AM, James Morse wrote:
>> When a CPU is taken offline resctrl may need to move the overflow or
>> limbo handlers to run on a different CPU.
>>
>> Once the offline callbacks have been split, cqm_setup_limbo_handler()
>> will be called while the CPU that is going offline is still present
>> in the cpu_mask.
>>
>> Pass the CPU to exclude to cqm_setup_limbo_handler() and
>> mbm_setup_overflow_handler(). These functions can use a variant of
>> cpumask_any_but() when selecting the CPU. -1 is used to indicate no CPUs
>> need excluding.
>>
>> A subsequent patch moves these calls to be before CPUs have been removed,
>> so this exclude_cpus behaviour is temporary.
>> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
>> index c0b1ad8d8f6d..471cdc4e4eae 100644
>> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
>> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
>> @@ -816,15 +817,28 @@ void cqm_handle_limbo(struct work_struct *work)
>> mutex_unlock(&rdtgroup_mutex);
>> }
>>
>> -void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms)
>> +/**
>> + * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this
>> + * domain.
>> + * @delay_ms: How far in the future the handler should run.
>> + * @exclude_cpu: Which CPU the handler should not run on,
>> + * RESCTRL_PICK_ANY_CPU to pick any CPU.
>> + */
>> +void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms,
>> + int exclude_cpu)
>> {
>> unsigned long delay = msecs_to_jiffies(delay_ms);
>> int cpu;
>>
>> - cpu = cpumask_any_housekeeping(&dom->cpu_mask);
>> + if (exclude_cpu == RESCTRL_PICK_ANY_CPU)
>> + cpu = cpumask_any_housekeeping(&dom->cpu_mask);
>> + else
>> + cpu = cpumask_any_housekeeping_but(&dom->cpu_mask,
>> + exclude_cpu);
>
> Having callers need to do this checking seems unnecessary and makes the
> code complicated. Can cpumask_any_housekeeping_but() instead be made
> slightly smarter to handle the case where exclude_cpu == RESCTRL_PICK_ANY_CPU ?
>
> Looks like there is a bit of duplication between
> cpumask_any_housekeeping() and cpumask_any_housekeeping_but().
Yup, this was because I was originally going to add them to cpumask.h, but figured it
would be easier to leave them here - in a shape that could be moved to cpumask.h if anyone
else needs them.
Using one helper for both would simplify things for resctrl, I'll do that.
Thanks,
James
next prev parent reply other threads:[~2023-08-24 16:59 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-28 16:42 [PATCH v5 00/24] x86/resctrl: monitored closid+rmid together, separate arch/fs locking James Morse
2023-07-28 16:42 ` [PATCH v5 01/24] x86/resctrl: Track the closid with the rmid James Morse
2023-08-09 22:32 ` Reinette Chatre
2023-08-24 16:50 ` James Morse
2023-08-15 0:09 ` Fenghua Yu
2023-07-28 16:42 ` [PATCH v5 02/24] x86/resctrl: Access per-rmid structures by index James Morse
2023-08-09 22:32 ` Reinette Chatre
2023-08-24 16:51 ` James Morse
2023-08-25 0:29 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 03/24] x86/resctrl: Create helper for RMID allocation and mondata dir creation James Morse
2023-08-09 22:32 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 04/24] x86/resctrl: Move rmid allocation out of mkdir_rdt_prepare() James Morse
2023-08-15 0:50 ` Fenghua Yu
2023-08-24 16:52 ` James Morse
2023-07-28 16:42 ` [PATCH v5 05/24] x86/resctrl: Allow RMID allocation to be scoped by CLOSID James Morse
2023-08-09 22:33 ` Reinette Chatre
2023-08-15 1:22 ` Fenghua Yu
2023-07-28 16:42 ` [PATCH v5 06/24] x86/resctrl: Track the number of dirty RMID a CLOSID has James Morse
2023-08-09 22:33 ` Reinette Chatre
2023-08-24 16:53 ` James Morse
2023-08-24 22:58 ` Reinette Chatre
2023-08-30 22:32 ` Tony Luck
2023-08-14 23:58 ` Fenghua Yu
2023-08-15 2:37 ` Fenghua Yu
2023-08-24 16:53 ` James Morse
2023-07-28 16:42 ` [PATCH v5 07/24] x86/resctrl: Use set_bit()/clear_bit() instead of open coding James Morse
2023-07-28 16:42 ` [PATCH v5 08/24] x86/resctrl: Allocate the cleanest CLOSID by searching closid_num_dirty_rmid James Morse
2023-08-15 2:59 ` Fenghua Yu
2023-08-24 16:54 ` James Morse
2023-07-28 16:42 ` [PATCH v5 09/24] x86/resctrl: Move CLOSID/RMID matching and setting to use helpers James Morse
2023-07-28 16:42 ` [PATCH v5 10/24] tick/nohz: Move tick_nohz_full_mask declaration outside the #ifdef James Morse
2023-08-09 22:34 ` Reinette Chatre
2023-08-24 16:55 ` James Morse
2023-08-25 0:43 ` Reinette Chatre
2023-09-08 15:58 ` James Morse
2023-07-28 16:42 ` [PATCH v5 11/24] x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow James Morse
2023-07-28 16:42 ` [PATCH v5 12/24] x86/resctrl: Make resctrl_arch_rmid_read() retry when it is interrupted James Morse
2023-08-09 22:35 ` Reinette Chatre
2023-08-24 16:55 ` James Morse
2023-08-24 23:01 ` Reinette Chatre
2023-09-08 15:58 ` James Morse
2023-09-08 20:15 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 13/24] x86/resctrl: Queue mon_event_read() instead of sending an IPI James Morse
2023-07-28 16:42 ` [PATCH v5 14/24] x86/resctrl: Allow resctrl_arch_rmid_read() to sleep James Morse
2023-08-09 22:36 ` Reinette Chatre
2023-08-24 16:56 ` James Morse
2023-08-24 23:02 ` Reinette Chatre
2023-09-08 15:58 ` James Morse
2023-09-08 20:15 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 15/24] x86/resctrl: Allow arch to allocate memory needed in resctrl_arch_rmid_read() James Morse
2023-08-09 22:37 ` Reinette Chatre
2023-08-24 16:56 ` James Morse
2023-08-24 23:04 ` Reinette Chatre
2023-09-15 17:37 ` James Morse
2023-07-28 16:42 ` [PATCH v5 16/24] x86/resctrl: Make resctrl_mounted checks explicit James Morse
2023-07-28 16:42 ` [PATCH v5 17/24] x86/resctrl: Move alloc/mon static keys into helpers James Morse
2023-07-28 16:42 ` [PATCH v5 18/24] x86/resctrl: Make rdt_enable_key the arch's decision to switch James Morse
2023-07-28 16:42 ` [PATCH v5 19/24] x86/resctrl: Add helpers for system wide mon/alloc capable James Morse
2023-08-17 18:34 ` Fenghua Yu
2023-08-24 16:57 ` James Morse
2023-07-28 16:42 ` [PATCH v5 20/24] x86/resctrl: Add cpu online callback for resctrl work James Morse
2023-08-09 22:38 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 21/24] x86/resctrl: Allow overflow/limbo handlers to be scheduled on any-but cpu James Morse
2023-08-09 22:38 ` Reinette Chatre
2023-08-24 16:57 ` James Morse [this message]
2023-07-28 16:42 ` [PATCH v5 22/24] x86/resctrl: Add cpu offline callback for resctrl work James Morse
2023-07-28 16:42 ` [PATCH v5 23/24] x86/resctrl: Move domain helper migration into resctrl_offline_cpu() James Morse
2023-08-09 22:39 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 24/24] x86/resctrl: Separate arch and fs resctrl locks James Morse
2023-08-09 22:41 ` Reinette Chatre
2023-08-24 16:57 ` James Morse
2023-08-18 22:05 ` Fenghua Yu
2023-08-24 16:58 ` James Morse
2023-08-03 7:34 ` [PATCH v5 00/24] x86/resctrl: monitored closid+rmid together, separate arch/fs locking Shaopeng Tan (Fujitsu)
2023-08-24 16:58 ` James Morse
2023-08-22 8:42 ` Peter Newman
2023-08-24 16:58 ` James Morse
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