[PATCH v1 0/3] kselftest/arm64: fp-stress updates

[PATCH v1 0/3] kselftest/arm64: fp-stress updates

[Mark Brown]

A few small updates for fp-stress, improving the usability with
signal handling a bit.

Mark Brown (3):
  kselftest/arm64: Don't repeat termination handler for fp-stress
  kselftest/arm64: Flag fp-stress as exiting when we begin finishing up
  kselftest/arm64: Handle EINTR while reading data from children

 tools/testing/selftests/arm64/fp/fp-stress.c | 90 ++++++++++++--------
 1 file changed, 55 insertions(+), 35 deletions(-)


base-commit: ea84edbf08025e592f58b0d9b282777a9ca9fb22
-- 
2.30.2


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[PATCH v1 1/3] kselftest/arm64: Don't repeat termination handler for fp-stress

[Mark Brown]

When fp-stress gets a termination signal it sets a flag telling itself to
exit and sends a termination signal to all the children. If the flag is set
then don't bother repeating this process, it isn't going to accomplish
anything other than consume CPU time which can be an issue when running in
emulation.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/fp/fp-stress.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/arm64/fp/fp-stress.c b/tools/testing/selftests/arm64/fp/fp-stress.c
index a5c0ebef2419..4387c3cacaa7 100644
--- a/tools/testing/selftests/arm64/fp/fp-stress.c
+++ b/tools/testing/selftests/arm64/fp/fp-stress.c
@@ -255,6 +255,10 @@ static void handle_exit_signal(int sig, siginfo_t *info, void *context)
 {
 	int i;
 
+	/* If we're already exiting then don't signal again */
+	if (terminate)
+		return;
+
 	ksft_print_msg("Got signal, exiting...\n");
 
 	terminate = true;
-- 
2.30.2


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[PATCH v1 2/3] kselftest/arm64: Flag fp-stress as exiting when we begin finishing up

[Mark Brown]

Once we have started exiting the termination handler will have the same
effect as what we're already running so set the termination flag at that
point.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/fp/fp-stress.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/arm64/fp/fp-stress.c b/tools/testing/selftests/arm64/fp/fp-stress.c
index 4387c3cacaa7..03ce3936220a 100644
--- a/tools/testing/selftests/arm64/fp/fp-stress.c
+++ b/tools/testing/selftests/arm64/fp/fp-stress.c
@@ -522,6 +522,7 @@ int main(int argc, char **argv)
 	}
 
 	ksft_print_msg("Finishing up...\n");
+	terminate = true;
 
 	for (i = 0; i < tests; i++)
 		child_stop(&children[i]);
-- 
2.30.2


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[PATCH v1 3/3] kselftest/arm64: Handle EINTR while reading data from children

[Mark Brown]

Currently we treat any error when reading from the child as a failure and
don't read any more output from that child as a result. This ignores the
fact that it is valid for read() to return EINTR as the error code if there
is a signal pending so we could stop handling the output of children,
especially during exit when we will get some SIGCHLD signals delivered to
us. Fix this by pulling the read handling out into a separate function
which returns a flag if reads should be continued and wrapping it in a
loop.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/fp/fp-stress.c | 85 ++++++++++++--------
 1 file changed, 50 insertions(+), 35 deletions(-)

diff --git a/tools/testing/selftests/arm64/fp/fp-stress.c b/tools/testing/selftests/arm64/fp/fp-stress.c
index 03ce3936220a..4e62a9199f97 100644
--- a/tools/testing/selftests/arm64/fp/fp-stress.c
+++ b/tools/testing/selftests/arm64/fp/fp-stress.c
@@ -121,55 +121,70 @@ static void child_start(struct child_data *child, const char *program)
 	}
 }
 
-static void child_output(struct child_data *child, uint32_t events,
-			 bool flush)
+static bool child_output_read(struct child_data *child)
 {
 	char read_data[1024];
 	char work[1024];
 	int ret, len, cur_work, cur_read;
 
-	if (events & EPOLLIN) {
-		ret = read(child->stdout, read_data, sizeof(read_data));
-		if (ret < 0) {
-			ksft_print_msg("%s: read() failed: %s (%d)\n",
-				       child->name, strerror(errno), errno);
-			return;
-		}
-		len = ret;
+	ret = read(child->stdout, read_data, sizeof(read_data));
+	if (ret < 0) {
+		if (errno == EINTR)
+			return true;
 
-		child->output_seen = true;
+		ksft_print_msg("%s: read() failed: %s (%d)\n",
+			       child->name, strerror(errno),
+			       errno);
+		return false;
+	}
+	len = ret;
 
-		/* Pick up any partial read */
-		if (child->output) {
-			strncpy(work, child->output, sizeof(work) - 1);
-			cur_work = strnlen(work, sizeof(work));
-			free(child->output);
-			child->output = NULL;
-		} else {
-			cur_work = 0;
-		}
+	child->output_seen = true;
 
-		cur_read = 0;
-		while (cur_read < len) {
-			work[cur_work] = read_data[cur_read++];
+	/* Pick up any partial read */
+	if (child->output) {
+		strncpy(work, child->output, sizeof(work) - 1);
+		cur_work = strnlen(work, sizeof(work));
+		free(child->output);
+		child->output = NULL;
+	} else {
+		cur_work = 0;
+	}
 
-			if (work[cur_work] == '\n') {
-				work[cur_work] = '\0';
-				ksft_print_msg("%s: %s\n", child->name, work);
-				cur_work = 0;
-			} else {
-				cur_work++;
-			}
-		}
+	cur_read = 0;
+	while (cur_read < len) {
+		work[cur_work] = read_data[cur_read++];
 
-		if (cur_work) {
+		if (work[cur_work] == '\n') {
 			work[cur_work] = '\0';
-			ret = asprintf(&child->output, "%s", work);
-			if (ret == -1)
-				ksft_exit_fail_msg("Out of memory\n");
+			ksft_print_msg("%s: %s\n", child->name, work);
+			cur_work = 0;
+		} else {
+			cur_work++;
 		}
 	}
 
+	if (cur_work) {
+		work[cur_work] = '\0';
+		ret = asprintf(&child->output, "%s", work);
+		if (ret == -1)
+			ksft_exit_fail_msg("Out of memory\n");
+	}
+
+	return false;
+}
+
+static void child_output(struct child_data *child, uint32_t events,
+			 bool flush)
+{
+	bool read_more;
+
+	if (events & EPOLLIN) {
+		do {
+			read_more = child_output_read(child);
+		} while (read_more);
+	}
+
 	if (events & EPOLLHUP) {
 		close(child->stdout);
 		child->stdout = -1;
-- 
2.30.2


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Re: [PATCH v1 0/3] kselftest/arm64: fp-stress updates

[Catalin Marinas]

On Wed, 21 Sep 2022 19:13:42 +0100, Mark Brown wrote:
> A few small updates for fp-stress, improving the usability with
> signal handling a bit.
> 
> Mark Brown (3):
>   kselftest/arm64: Don't repeat termination handler for fp-stress
>   kselftest/arm64: Flag fp-stress as exiting when we begin finishing up
>   kselftest/arm64: Handle EINTR while reading data from children
> 
> [...]

Applied to arm64 (for-next/kselftest), thanks!

[1/3] kselftest/arm64: Don't repeat termination handler for fp-stress
      https://git.kernel.org/arm64/c/c38d381fff26
[2/3] kselftest/arm64: Flag fp-stress as exiting when we begin finishing up
      https://git.kernel.org/arm64/c/dd72dd7cd527
[3/3] kselftest/arm64: Handle EINTR while reading data from children
      https://git.kernel.org/arm64/c/a711987490a1

-- 
Catalin


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