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From: Denys Vlasenko <dvlasenk@redhat.com>
To: "Christian König" <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] radeon: Deinline indirect register accessor functions
Date: Mon, 18 May 2015 20:50:09 +0200	[thread overview]
Message-ID: <555A3461.90000@redhat.com> (raw)
In-Reply-To: <555A2A1E.9000706@amd.com>

On 05/18/2015 08:06 PM, Christian König wrote:
> I'm actually surprised how often people come along with that. The last time we tried this it caused a noticeable performance drop.
> 
> Basic problem is that this line:
>> +    if ((reg < rdev->rmmio_size || reg < RADEON_MIN_MMIO_SIZE) && !always_indirect)
> optimizes away in most of the cases which reduces the call to a readl which is way faster than the spinlock path.
> 
> So this is a NAK,


Fair enough.

I'm preparing a v2 where the fast branch of r100_mm_{r,w}reg() will stay inlined.


  reply	other threads:[~2015-05-18 18:50 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-18 17:59 [PATCH] radeon: Deinline indirect register accessor functions Denys Vlasenko
2015-05-18 17:59 ` [PATCH] radeon: Shrink radeon_ring_write() Denys Vlasenko
2015-05-18 18:11   ` Christian König
2015-05-18 18:25     ` Denys Vlasenko
2015-05-18 19:01       ` Christian König
2015-05-18 18:06 ` [PATCH] radeon: Deinline indirect register accessor functions Christian König
2015-05-18 18:50   ` Denys Vlasenko [this message]
2015-05-18 19:04     ` Christian König
2015-05-18 19:22       ` Ilia Mirkin

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