Re: [patch 5/7] dma-pool: add pool sizes to debugfs

From: Christoph Hellwig
Date: Fri Apr 17 2020 - 03:10:27 EST


On Wed, Apr 15, 2020 at 08:45:08AM -0500, Tom Lendacky wrote:
>
>
> On 4/14/20 7:04 PM, David Rientjes wrote:
>> The atomic DMA pools can dynamically expand based on non-blocking
>> allocations that need to use it.
>>
>> Export the sizes of each of these pools, in bytes, through debugfs for
>> measurement.
>>
>> Suggested-by: Christoph Hellwig <hch@xxxxxx>
>> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
>> ---
>> kernel/dma/pool.c | 41 +++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 41 insertions(+)
>>
>> diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
>> index cf052314d9e4..3e22022c933b 100644
>> --- a/kernel/dma/pool.c
>> +++ b/kernel/dma/pool.c
>> @@ -2,6 +2,7 @@
>> /*
>> * Copyright (C) 2020 Google LLC
>> */
>> +#include <linux/debugfs.h>
>> #include <linux/dma-direct.h>
>> #include <linux/dma-noncoherent.h>
>> #include <linux/dma-contiguous.h>
>> @@ -15,6 +16,11 @@
>> static struct gen_pool *atomic_pool_dma __ro_after_init;
>> static struct gen_pool *atomic_pool_dma32 __ro_after_init;
>> static struct gen_pool *atomic_pool_kernel __ro_after_init;
>> +#ifdef CONFIG_DEBUG_FS
>
> I don't think you need the #ifdef any more unless you just want to save
> space. All of the debugfs routines have versions for whether
> CONFIG_DEBUG_FS is defined or not.

Agreed. I can fix this up.