[PATCH v2 -perf/core 1/2] perf mmap: Discard head in overwrite_rb_find_range

[PATCH v2 -perf/core 1/2] perf mmap: Discard head in overwrite_rb_find_range

[Yisheng Xie]

In overwrite mode, start will be set to head in perf_mmap__read_init.
Therefore, it is no need to set the start one more in
overwrite_rb_find_range and *start can be used as head instead of
passing head to overwrite_rb_find_range.

Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
---
v2:
 - rebase to perf/core

 tools/perf/util/mmap.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 074c4fd..38ca3ff 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -199,19 +199,18 @@ int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd)
 	return 0;
 }
 
-static int overwrite_rb_find_range(void *buf, int mask, u64 head, u64 *start, u64 *end)
+static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end)
 {
 	struct perf_event_header *pheader;
-	u64 evt_head = head;
+	u64 evt_head = *start;
 	int size = mask + 1;
 
-	pr_debug2("overwrite_rb_find_range: buf=%p, head=%"PRIx64"\n", buf, head);
-	pheader = (struct perf_event_header *)(buf + (head & mask));
-	*start = head;
+	pr_debug2("%s: buf=%p, start=%"PRIx64"\n", __func__, buf, *start);
+	pheader = (struct perf_event_header *)(buf + (*start & mask));
 	while (true) {
-		if (evt_head - head >= (unsigned int)size) {
+		if (evt_head - *start >= (unsigned int)size) {
 			pr_debug("Finished reading overwrite ring buffer: rewind\n");
-			if (evt_head - head > (unsigned int)size)
+			if (evt_head - *start > (unsigned int)size)
 				evt_head -= pheader->size;
 			*end = evt_head;
 			return 0;
@@ -262,7 +261,7 @@ int perf_mmap__read_init(struct perf_mmap *md)
 		 * Backward ring buffer is full. We still have a chance to read
 		 * most of data from it.
 		 */
-		if (overwrite_rb_find_range(data, md->mask, head, &md->start, &md->end))
+		if (overwrite_rb_find_range(data, md->mask, &md->start, &md->end))
 			return -EINVAL;
 	}
 
-- 
1.7.12.4

[PATCH v2 -perf/core 2/2] perf debug: Avoid set quiet once more

[Yisheng Xie]

When use --quiet to disable log, we will set quiet first, then check the
quiet to decide whether need to call perf_quiet_option, so no need to set
the quiet once more.

Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
---
 - This is a new add-on patch

 tools/perf/util/debug.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index f3a71db..3d64596 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -232,7 +232,6 @@ int perf_quiet_option(void)
 		var++;
 	}
 
-	quiet = true;
 	return 0;
 }
 
-- 
1.7.12.4

[tip:perf/core] perf debug: Avoid setting 'quiet' to 'true' unnecessarily

[tip-bot for Yisheng Xie]

Commit-ID:  a08f6dd4190e90dc7b013435acb66770f117e8b0
Gitweb:     https://git.kernel.org/tip/a08f6dd4190e90dc7b013435acb66770f117e8b0
Author:     Yisheng Xie <xieyisheng1@huawei.com>
AuthorDate: Tue, 13 Mar 2018 20:31:14 +0800
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 16 Mar 2018 16:39:02 -0300

perf debug: Avoid setting 'quiet' to 'true' unnecessarily

When using --quiet to disable messages, we will set the 'quiet' variable
to 'true' first, then check that variable to decide whether we need to
call perf_quiet_option(), so no need to set 'quiet' to 'true' once more
in perf_quiet_option().

Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1520944274-37001-2-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/debug.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index f3a71db83947..3d6459626c2a 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -232,7 +232,6 @@ int perf_quiet_option(void)
 		var++;
 	}
 
-	quiet = true;
 	return 0;
 }
 

Re: [PATCH v2 -perf/core 1/2] perf mmap: Discard head in overwrite_rb_find_range

[Liang, Kan]

On 3/13/2018 8:31 AM, Yisheng Xie wrote:
> In overwrite mode, start will be set to head in perf_mmap__read_init.
> Therefore, it is no need to set the start one more in
> overwrite_rb_find_range and *start can be used as head instead of
> passing head to overwrite_rb_find_range.
>

Looks good to me.

Reviewed-by: Kan Liang <kan.liang@linux.intel.com>

Thanks,
Kan

> Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
> ---
> v2:
>   - rebase to perf/core
> 
>   tools/perf/util/mmap.c | 15 +++++++--------
>   1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
> index 074c4fd..38ca3ff 100644
> --- a/tools/perf/util/mmap.c
> +++ b/tools/perf/util/mmap.c
> @@ -199,19 +199,18 @@ int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd)
>   	return 0;
>   }
>   
> -static int overwrite_rb_find_range(void *buf, int mask, u64 head, u64 *start, u64 *end)
> +static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end)
>   {
>   	struct perf_event_header *pheader;
> -	u64 evt_head = head;
> +	u64 evt_head = *start;
>   	int size = mask + 1;
>   
> -	pr_debug2("overwrite_rb_find_range: buf=%p, head=%"PRIx64"\n", buf, head);
> -	pheader = (struct perf_event_header *)(buf + (head & mask));
> -	*start = head;
> +	pr_debug2("%s: buf=%p, start=%"PRIx64"\n", __func__, buf, *start);
> +	pheader = (struct perf_event_header *)(buf + (*start & mask));
>   	while (true) {
> -		if (evt_head - head >= (unsigned int)size) {
> +		if (evt_head - *start >= (unsigned int)size) {
>   			pr_debug("Finished reading overwrite ring buffer: rewind\n");
> -			if (evt_head - head > (unsigned int)size)
> +			if (evt_head - *start > (unsigned int)size)
>   				evt_head -= pheader->size;
>   			*end = evt_head;
>   			return 0;
> @@ -262,7 +261,7 @@ int perf_mmap__read_init(struct perf_mmap *md)
>   		 * Backward ring buffer is full. We still have a chance to read
>   		 * most of data from it.
>   		 */
> -		if (overwrite_rb_find_range(data, md->mask, head, &md->start, &md->end))
> +		if (overwrite_rb_find_range(data, md->mask, &md->start, &md->end))
>   			return -EINVAL;
>   	}
>   
> 

[tip:perf/core] perf mmap: Discard head in overwrite_rb_find_range()

[tip-bot for Yisheng Xie]

Commit-ID:  699db111058798bcc9f92a93767062905a561bef
Gitweb:     https://git.kernel.org/tip/699db111058798bcc9f92a93767062905a561bef
Author:     Yisheng Xie <xieyisheng1@huawei.com>
AuthorDate: Tue, 13 Mar 2018 20:31:13 +0800
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 16 Mar 2018 16:33:05 -0300

perf mmap: Discard head in overwrite_rb_find_range()

In overwrite mode, start will be set to head in perf_mmap__read_init().
Therefore, there is no need to set the start one more time in
overwrite_rb_find_range() and *start can be used as head instead of
passing head to overwrite_rb_find_range().

Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1520944274-37001-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/mmap.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 074c4fd3b67e..38ca3ffb9d61 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -199,19 +199,18 @@ int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd)
 	return 0;
 }
 
-static int overwrite_rb_find_range(void *buf, int mask, u64 head, u64 *start, u64 *end)
+static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end)
 {
 	struct perf_event_header *pheader;
-	u64 evt_head = head;
+	u64 evt_head = *start;
 	int size = mask + 1;
 
-	pr_debug2("overwrite_rb_find_range: buf=%p, head=%"PRIx64"\n", buf, head);
-	pheader = (struct perf_event_header *)(buf + (head & mask));
-	*start = head;
+	pr_debug2("%s: buf=%p, start=%"PRIx64"\n", __func__, buf, *start);
+	pheader = (struct perf_event_header *)(buf + (*start & mask));
 	while (true) {
-		if (evt_head - head >= (unsigned int)size) {
+		if (evt_head - *start >= (unsigned int)size) {
 			pr_debug("Finished reading overwrite ring buffer: rewind\n");
-			if (evt_head - head > (unsigned int)size)
+			if (evt_head - *start > (unsigned int)size)
 				evt_head -= pheader->size;
 			*end = evt_head;
 			return 0;
@@ -262,7 +261,7 @@ int perf_mmap__read_init(struct perf_mmap *md)
 		 * Backward ring buffer is full. We still have a chance to read
 		 * most of data from it.
 		 */
-		if (overwrite_rb_find_range(data, md->mask, head, &md->start, &md->end))
+		if (overwrite_rb_find_range(data, md->mask, &md->start, &md->end))
 			return -EINVAL;
 	}