From: Thomas Gleixner <tglx@linutronix.de>
To: Qian Cai <cai@gmx.us>
Cc: akpm@linux-foundation.org, longman@redhat.com,
yang.shi@linux.alibaba.com, arnd@arndb.de,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] debugobjects: add a new Kconfig for POOL_SIZE
Date: Sun, 18 Nov 2018 19:21:24 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.21.1811181919170.9459@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20181118082255.1275-1-cai@gmx.us>
Qian,
On Sun, 18 Nov 2018, Qian Cai wrote:
> The current value of ODEBUG_POOL_SIZE is not big enough for large memory
> systems with timer or/and workqueue objects because during the early
> boot, timer objects needs at least the size equals to
>
> No. CPUs x 2 (worker pool)
>
> start_kernel
> workqueue_init_early
> init_worker_pool
> init_timer_key
> debug_object_init
>
> puls, No. CPUs
>
> start_kernel
> sched_init
> hrtimer_init
> debug_object_init
>
> Then, workqueue objects requires even more,
>
> No. CPUs x 2 (worker pool) x 6 (workqueue)
>
> start_kernel
> workqueue_init_early
> __alloc_workqueue_key
> alloc_workqueue
> init_pwq
> debug_object_init
>
> plus, No, CPUs x 2 (worker pool)
>
> start_kernel
> perf_event_init
> __init_srcu_struct
> init_srcu_struct_fields
> __init_work
> debug_object_init
>
> As the results, systems have 60+ CPUs with both timer and workqueue
> objects enabled could trigger "ODEBUG: Out of memory. ODEBUG disabled".
>
> Hence, add a new Kconfig option so users could adjust ODEBUG_POOL_SIZE
> accordingly if either timer or workqueue objects are selected.
why do we need a config option, when the required number can be deduced
already from the active CONFIG_DEBUG_OBJECTS_* and NR_CPUS?
Thanks,
tglx
next prev parent reply other threads:[~2018-11-18 18:21 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-18 8:22 [PATCH] debugobjects: add a new Kconfig for POOL_SIZE Qian Cai
2018-11-18 18:21 ` Thomas Gleixner [this message]
2018-11-18 18:56 ` Qian Cai
2018-11-19 8:09 ` Thomas Gleixner
2018-11-19 13:27 ` Qian Cai
2018-11-19 14:51 ` Waiman Long
2018-11-19 15:17 ` Qian Cai
2018-11-19 16:19 ` Waiman Long
2018-11-19 16:25 ` Thomas Gleixner
2018-11-19 16:32 ` Qian Cai
2018-11-18 22:08 ` [PATCH v2] " Qian Cai
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