From: Uladzislau Rezki <urezki@gmail.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Wagner <dwagner@suse.de>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-rt-users@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Uladzislau Rezki <urezki@gmail.com>
Subject: Re: [PATCH] mm: vmalloc: Use the vmap_area_lock to protect ne_fit_preload_node
Date: Fri, 4 Oct 2019 18:20:41 +0200 [thread overview]
Message-ID: <20191004162041.GA30806@pc636> (raw)
In-Reply-To: <20191004153728.c5xppuqwqcwecbe6@linutronix.de>
On Fri, Oct 04, 2019 at 05:37:28PM +0200, Sebastian Andrzej Siewior wrote:
> If you post something that is related to PREEMPT_RT please keep tglx and
> me in Cc.
>
> On 2019-10-03 11:09:06 [+0200], Daniel Wagner wrote:
> > Replace preempt_enable() and preempt_disable() with the vmap_area_lock
> > spin_lock instead. Calling spin_lock() with preempt disabled is
> > illegal for -rt. Furthermore, enabling preemption inside the
>
> Looking at it again, I have reasonable doubt that this
> preempt_disable() is needed.
>
The intention was to preload a current CPU with one extra object in
non-atomic context, thus to use GFP_KERNEL permissive parameters. I.e.
that allows us to avoid any allocation(if we stay on the same CPU)
when we are in atomic context do splitting.
If we have migrate_disable/enable, then, i think preempt_enable/disable
should be replaced by it and not the way how it has been proposed
in the patch.
--
Vlad Rezki
next prev parent reply other threads:[~2019-10-04 16:20 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-03 9:09 [PATCH] mm: vmalloc: Use the vmap_area_lock to protect ne_fit_preload_node Daniel Wagner
2019-10-03 11:55 ` Uladzislau Rezki
2019-10-04 15:37 ` Sebastian Andrzej Siewior
2019-10-04 16:20 ` Uladzislau Rezki [this message]
2019-10-04 16:30 ` Sebastian Andrzej Siewior
2019-10-04 17:04 ` Uladzislau Rezki
2019-10-04 17:45 ` Sebastian Andrzej Siewior
2019-10-07 8:30 ` Daniel Wagner
2019-10-07 10:56 ` Sebastian Andrzej Siewior
2019-10-07 16:23 ` Uladzislau Rezki
2019-10-07 16:34 ` Daniel Wagner
2019-10-07 16:56 ` Uladzislau Rezki
2019-10-07 17:22 ` Daniel Wagner
2019-10-07 17:36 ` Sebastian Andrzej Siewior
2019-10-07 21:44 ` Uladzislau Rezki
2019-10-08 16:04 ` Uladzislau Rezki
2019-10-09 6:05 ` Daniel Wagner
2019-10-09 9:47 ` Uladzislau Rezki
2019-10-07 8:27 ` Daniel Wagner
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