From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Alistair Popple <alistair@popple.id.au>, linuxppc-dev@lists.ozlabs.org
Cc: Alistair Popple <alistair@popple.id.au>,
mhairgrove@nvidia.com, arbab@linux.ibm.com
Subject: Re: [1/2] powernv/npu: Do a PID GPU TLB flush when invalidating a large address range
Date: Tue, 24 Apr 2018 13:48:27 +1000 (AEST) [thread overview]
Message-ID: <40VTnl1sdMz9s1b@ozlabs.org> (raw)
In-Reply-To: <20180417091129.23069-1-alistair@popple.id.au>
On Tue, 2018-04-17 at 09:11:28 UTC, Alistair Popple wrote:
> The NPU has a limited number of address translation shootdown (ATSD)
> registers and the GPU has limited bandwidth to process ATSDs. This can
> result in contention of ATSD registers leading to soft lockups on some
> threads, particularly when invalidating a large address range in
> pnv_npu2_mn_invalidate_range().
>
> At some threshold it becomes more efficient to flush the entire GPU TLB for
> the given MM context (PID) than individually flushing each address in the
> range. This patch will result in ranges greater than 2MB being converted
> from 32+ ATSDs into a single ATSD which will flush the TLB for the given
> PID on each GPU.
>
> Signed-off-by: Alistair Popple <alistair@popple.id.au>
> Acked-by: Balbir Singh <bsingharora@gmail.com>
> Tested-by: Balbir Singh <bsingharora@gmail.com>
Patch 1 applied to powerpc fixes, thanks.
https://git.kernel.org/powerpc/c/d0cf9b561ca97d5245bb9e0c4774b7
cheers
prev parent reply other threads:[~2018-04-24 3:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-17 9:11 [PATCH 1/2] powernv/npu: Do a PID GPU TLB flush when invalidating a large address range Alistair Popple
2018-04-17 9:11 ` [PATCH 2/2] powernv/npu: Add a debugfs setting to change ATSD threshold Alistair Popple
2018-04-17 21:45 ` Balbir Singh
2018-07-23 15:11 ` [2/2] " Michael Ellerman
2018-04-17 9:17 ` [PATCH 1/2] powernv/npu: Do a PID GPU TLB flush when invalidating a large address range Balbir Singh
2018-04-17 22:25 ` Balbir Singh
2018-04-20 3:51 ` Alistair Popple
2018-04-24 3:48 ` Michael Ellerman [this message]
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