From: Sebastian Andrzej Siewior <bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
To: Scott Wood <swood-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 00/10 v2] iommu/amd: lock splitting & GFP_KERNEL allocation
Date: Mon, 19 Mar 2018 13:15:27 +0100 [thread overview]
Message-ID: <20180319121527.zdmuwid4i3mjpwjw@linutronix.de> (raw)
In-Reply-To: <1521323019.3722.98.camel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
On 2018-03-17 16:43:39 [-0500], Scott Wood wrote:
> If that's worth the lock dropping then fine (though why does only one
> of the two allocations use GFP_KERNEL?), but it doesn't need to be a
That was a mistake, I planned to keep both as GFP_KERNEL.
> raw lock if the non-allocating users are separated. Keeping them
> separate will also preserve the WARNs if we somehow end up in an atomic
> context with no table (versus relying on atomic sleep debugging that
> may or may not be enabled), and make the code easier to understand by
> being explicit about which functions can be used from RT-atomic
> context.
That separated part is okay. We could keep it. However, I am not sure if
looking at the table irq_lookup_table[devid] without the lock is okay.
The pointer is assigned without DTE entry/iommu-flush to be completed.
This does not look "okay".
> -Scott
>
Sebastian
next prev parent reply other threads:[~2018-03-19 12:15 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-16 20:18 [PATCH 00/10 v2] iommu/amd: lock splitting & GFP_KERNEL allocation Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 05/10] Revert "iommu/amd: Avoid locking get_irq_table() from atomic context" Sebastian Andrzej Siewior
[not found] ` <20180316201836.7864-1-bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
2018-03-16 20:18 ` [PATCH 01/10] iommu/amd: take into account that alloc_dev_data() may return NULL Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 02/10] iommu/amd: turn dev_data_list into a lock less list Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 03/10] iommu/amd: split domain id out of amd_iommu_devtable_lock Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 04/10] iommu/amd: split irq_lookup_table out of the amd_iommu_devtable_lock Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 06/10] iommu/amd: remove the special case from get_irq_table() Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 07/10] iommu/amd: use `table' instead `irt' as variable name in amd_iommu_update_ga() Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 08/10] iommu/amd: factor out setting the remap table for a devid Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 09/10] iommu/amd: drop the lock while allocating new irq remap table Sebastian Andrzej Siewior
2018-03-16 20:18 ` [PATCH 10/10] iommu/amd: make amd_iommu_devtable_lock a spin_lock Sebastian Andrzej Siewior
2018-03-17 19:49 ` [PATCH 00/10 v2] iommu/amd: lock splitting & GFP_KERNEL allocation Scott Wood
[not found] ` <1521316194.3722.74.camel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-03-17 21:10 ` Sebastian Andrzej Siewior
[not found] ` <20180317211013.rlou66s542ad4y2i-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
2018-03-17 21:43 ` Scott Wood
[not found] ` <1521323019.3722.98.camel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-03-19 12:15 ` Sebastian Andrzej Siewior [this message]
2018-03-19 22:49 ` Scott Wood
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