From: Leo Yan <leo.yan@linaro.org>
To: Daniel Kiss <daniel.kiss@arm.com>
Cc: mathieu.poirier@linaro.org, suzuki.poulose@arm.com,
mike.leach@linaro.org, coresight@lists.linaro.org,
linux-arm-kernel@lists.infradead.org, denik@google.com,
Branislav Rankov <Branislav.Rankov@arm.com>
Subject: Re: [PATCH 1/4] coresight: tmc-etr: Advance buffer pointer in sync buffer.
Date: Fri, 23 Apr 2021 16:23:04 +0800 [thread overview]
Message-ID: <20210423082304.GA377091@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <20210421120413.3110775-2-daniel.kiss@arm.com>
On Wed, Apr 21, 2021 at 02:04:10PM +0200, Daniel Kiss wrote:
> With polling the sync could called multiple times in a row. Without this
> change the data will be overwritten at the beginning of the buffer.
>
> Signed-off-by: Daniel Kiss <daniel.kiss@arm.com>
> Signed-off-by: Branislav Rankov <Branislav.Rankov@arm.com>
From the last week, I spent time to dig into AUX trace buffer, thus
this patch set gives me a good chance to apply my learning for perf
ring buffer.
For this patch:
Reviewed-by: Leo Yan <leo.yan@linaro.org>
> ---
> drivers/hwtracing/coresight/coresight-tmc-etr.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index ea5027e397d02..dd19d1d1c3b38 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -1442,7 +1442,7 @@ static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,
> {
> long bytes;
> long pg_idx, pg_offset;
> - unsigned long head = etr_perf->head;
> + unsigned long head;
> char **dst_pages, *src_buf;
> struct etr_buf *etr_buf = etr_perf->etr_buf;
>
> @@ -1465,7 +1465,7 @@ static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,
> bytes = tmc_etr_buf_get_data(etr_buf, src_offset, to_copy,
> &src_buf);
> if (WARN_ON_ONCE(bytes <= 0))
> - break;
> + return;
> bytes = min(bytes, (long)(PAGE_SIZE - pg_offset));
>
> memcpy(dst_pages[pg_idx] + pg_offset, src_buf, bytes);
> @@ -1483,6 +1483,7 @@ static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,
> /* Move source pointers */
> src_offset += bytes;
> }
> + etr_perf->head = (pg_idx << PAGE_SHIFT) + pg_offset;
> }
>
> /*
> --
> 2.25.1
>
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next prev parent reply other threads:[~2021-04-23 8:25 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 12:04 [PATCH 0/4] coresight: Add ETR-PERF polling Daniel Kiss
2021-04-21 12:04 ` [PATCH 1/4] coresight: tmc-etr: Advance buffer pointer in sync buffer Daniel Kiss
2021-04-23 8:23 ` Leo Yan [this message]
2021-04-26 10:40 ` Suzuki K Poulose
2021-04-27 3:45 ` Leo Yan
2021-04-27 10:00 ` Suzuki K Poulose
2021-04-28 2:34 ` Leo Yan
2021-04-21 12:04 ` [PATCH 2/4] coresight: tmc-etr: Track perf handler Daniel Kiss
2021-04-23 9:20 ` Leo Yan
2021-04-26 0:25 ` Leo Yan
2021-04-21 12:04 ` [PATCH 3/4] coresight: etm-perf: Export etm_event_cpu_path Daniel Kiss
2021-04-21 12:04 ` [PATCH 4/4] coresight: Add ETR-PERF polling Daniel Kiss
2021-04-26 1:18 ` Leo Yan
2021-05-05 7:21 ` Denis Nikitin
2021-04-26 17:54 ` [PATCH 0/4] " Mathieu Poirier
2021-04-27 10:43 ` Al Grant
2021-04-27 14:41 ` Mike Leach
2021-04-27 15:47 ` Mathieu Poirier
2021-04-27 16:04 ` Leo Yan
2021-05-05 6:46 ` Denis Nikitin
2021-05-05 15:29 ` Mathieu Poirier
2021-05-14 9:02 ` Denis Nikitin
2021-05-14 16:16 ` Mike Leach
2021-05-18 14:00 ` Leo Yan
2021-05-18 14:14 ` Leo Yan
2021-05-18 15:41 ` Mathieu Poirier
2021-05-26 6:47 ` Denis Nikitin
2021-05-23 8:45 ` Leo Yan
2021-05-27 7:50 ` Denis Nikitin
2021-05-27 15:07 ` Leo Yan
2021-05-27 16:22 ` Denis Nikitin
2021-05-28 16:37 ` Leo Yan
2021-04-27 16:24 ` James Clark
2021-04-28 11:30 ` James Clark
2021-04-28 11:52 ` Daniel Kiss
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