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From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Anshuman Khandual <anshuman.khandual@arm.com>,
	coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, tamas.zsoldos@arm.com,
	al.grant@arm.com, leo.yan@linaro.org, mike.leach@linaro.org,
	mathieu.poirier@linaro.org, jinlmao@qti.qualcomm.com
Subject: Re: [PATCH v2 05/10] coresight: trbe: Drop duplicate TRUNCATE flags
Date: Fri, 30 Jul 2021 13:58:48 +0100	[thread overview]
Message-ID: <59ba694b-5bc3-1a51-38dc-7de90dff68ac@arm.com> (raw)
In-Reply-To: <0292cfc7-df67-aa45-4268-2ebc7f53420a@arm.com>

On 30/07/2021 05:47, Anshuman Khandual wrote:
> 
> 
> On 7/23/21 6:16 PM, Suzuki K Poulose wrote:
>> We mark the buffer as TRUNCATED when there is no space left
>> in the buffer. But we do it at different points.
>>      __trbe_normal_offset()
>> and also, at all the callers of the above function via
>> compute_trbe_buffer_limit(), when the limit == base (i.e
>> offset = 0 as returned by the __trbe_normal_offset()).
>>
>> So, given that the callers already mark the buffer as TRUNCATED
>> drop the caller inside the __trbe_normal_offset().
>>
>> This is in preparation to moving the handling of TRUNCATED
>> into a central place.
>>
>> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
>> Cc: Mike Leach <mike.leach@linaro.org>
>> Cc: Leo Yan <leo.yan@linaro.org>
>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>> ---
>>   drivers/hwtracing/coresight/coresight-trbe.c | 7 +------
>>   1 file changed, 1 insertion(+), 6 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
>> index 446f080f8320..62e1a08f73ff 100644
>> --- a/drivers/hwtracing/coresight/coresight-trbe.c
>> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
>> @@ -253,13 +253,9 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle)
>>   	 * trbe_base				trbe_base + nr_pages
>>   	 *
>>   	 * Perf aux buffer does not have any space for the driver to write into.
>> -	 * Just communicate trace truncation event to the user space by marking
>> -	 * it with PERF_AUX_FLAG_TRUNCATED.
>>   	 */
>> -	if (!handle->size) {
>> -		perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
>> +	if (!handle->size)
>>   		return 0;
>> -	}
>>   
>>   	/* Compute the tail and wakeup indices now that we've aligned head */
>>   	tail = PERF_IDX2OFF(handle->head + handle->size, buf);
>> @@ -361,7 +357,6 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle)
>>   		return limit;
>>   
>>   	trbe_pad_buf(handle, handle->size);
>> -	perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
>>   	return 0;
>>   }
> 
> What about in trbe_handle_spurious() path which used to set the flag via
> compute_trbe_buffer_limit(), but would not any more after this change. I
> guess following additional change would be required to preserve the past
> behaviour.
> 
> --- a/drivers/hwtracing/coresight/coresight-trbe.c
> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
> @@ -685,6 +685,7 @@ static void trbe_handle_spurious(struct perf_output_handle *handle)
>          buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf);
>          if (buf->trbe_limit == buf->trbe_base) {
>                  trbe_drain_and_disable_local();
> +               perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
>                  return;
>          }
>          trbe_enable_hw(buf);
> 

Agreed, I will add this.

Thanks
Suzuki

  reply	other threads:[~2021-07-30 12:58 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-23 12:46 [PATCH v2 00/10] coresight: TRBE and Self-Hosted trace fixes Suzuki K Poulose
2021-07-23 12:46 ` [PATCH v2 01/10] coresight: etm4x: Save restore TRFCR_EL1 Suzuki K Poulose
2021-07-30  3:05   ` Anshuman Khandual
2021-07-23 12:46 ` [PATCH v2 02/10] coresight: etm4x: Use Trace Filtering controls dynamically Suzuki K Poulose
2021-07-30  3:48   ` Anshuman Khandual
2021-07-30 11:29     ` Suzuki K Poulose
2021-07-23 12:46 ` [PATCH v2 03/10] coresight: etm-pmu: Ensure the AUX handle is valid Suzuki K Poulose
2021-07-30  4:14   ` Anshuman Khandual
2021-07-23 12:46 ` [PATCH v2 04/10] coresight: trbe: Ensure the format flag is set on truncation Suzuki K Poulose
2021-07-30  4:26   ` Anshuman Khandual
2021-07-30 11:37     ` Suzuki K Poulose
2021-07-23 12:46 ` [PATCH v2 05/10] coresight: trbe: Drop duplicate TRUNCATE flags Suzuki K Poulose
2021-07-30  4:47   ` Anshuman Khandual
2021-07-30 12:58     ` Suzuki K Poulose [this message]
2021-07-23 12:46 ` [PATCH v2 06/10] coresight: trbe: Fix handling of spurious interrupts Suzuki K Poulose
2021-07-30  5:15   ` Anshuman Khandual
2021-07-30 12:57     ` Suzuki K Poulose
2021-07-23 12:46 ` [PATCH v2 07/10] coresight: trbe: Do not truncate buffer on IRQ Suzuki K Poulose
2021-07-26 12:34   ` Mike Leach
2021-07-26 16:01     ` Suzuki K Poulose
2021-07-27 10:46       ` Mike Leach
2021-07-27 13:06         ` Suzuki K Poulose
2021-07-28  9:25           ` Suzuki K Poulose
2021-07-23 12:46 ` [PATCH v2 08/10] coresight: trbe: Unify the enabling sequence Suzuki K Poulose
2021-07-30  5:40   ` Anshuman Khandual
2021-07-23 12:46 ` [PATCH v2 09/10] coresight: trbe: End the AUX handle on truncation Suzuki K Poulose
2021-07-30  5:54   ` Anshuman Khandual
2021-07-23 12:46 ` [PATCH v2 10/10] coresight: trbe: Prohibit trace before disabling TRBE Suzuki K Poulose
2021-07-30  6:58   ` Anshuman Khandual
2021-07-23 13:45 ` [PATCH v2 00/10] coresight: TRBE and Self-Hosted trace fixes Suzuki K Poulose

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