On 5/30/2016 1:11 AM, Vinod Koul wrote:
> On Thu, May 19, 2016 at 01:39:58PM -0400, Sinan Kaya wrote:
>
>> From ec9f4480fac1648e9f53112b143a535774e3795d Mon Sep 17 00:00:00 2001
>> From: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
>> Date: Wed, 18 May 2016 16:57:15 -0400
>> Subject: [PATCH] dmatest: exclude compare and fill time during performance
>> report
>>
>> Change-Id: I3428a85c3a58f990b985fc10fe736dfb3e56b206
>
> We dont want these here...
>
Sure,
>> --- a/drivers/dma/dmatest.c
>> +++ b/drivers/dma/dmatest.c
>> @@ -416,7 +416,9 @@ static int dmatest_func(void *data)
>> int src_cnt;
>> int dst_cnt;
>> int i;
>> - ktime_t ktime;
>> + ktime_t ktime, start, diff;
>> + ktime_t filltime = ktime_set(0, 0);
>> + ktime_t comparetime = ktime_set(0, 0);
>> s64 runtime = 0;
>> unsigned long long total_len = 0;
>>
>> @@ -517,6 +519,7 @@ static int dmatest_func(void *data)
>> src_off = 0;
>> dst_off = 0;
>> } else {
>> + start = ktime_get();
>> src_off = dmatest_random() % (params->buf_size - len + 1);
>> dst_off = dmatest_random() % (params->buf_size - len + 1);
>>
>> @@ -527,6 +530,9 @@ static int dmatest_func(void *data)
>> params->buf_size);
>> dmatest_init_dsts(thread->dsts, dst_off, len,
>> params->buf_size);
>> +
>> + diff = ktime_sub(ktime_get(), start);
>
> If you are very picky about perf, shouldn't we just track time here and then
> later do subtraction to get diff
>
That's what I was originally doing. I realized that the loop gets called multiple
times before reaching to final point where the actual performance is measured.
I'm trying to account for multiple fills and compares by using a stack local variable.
Then, I deduct the final result.
--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
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