All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] selftests/rseq: Do not skip !allowed_cpus for mm_cid
@ 2024-01-11 15:49 Mathieu Desnoyers
  2024-01-22 18:43 ` Shuah Khan
  0 siblings, 1 reply; 3+ messages in thread
From: Mathieu Desnoyers @ 2024-01-11 15:49 UTC (permalink / raw)
  To: Shuah Khan
  Cc: linux-kernel, Mathieu Desnoyers, Peter Zijlstra,
	Paul E. McKenney, Boqun Feng

Indexing with mm_cid is incompatible with skipping disallowed cpumask,
because concurrency IDs are based on a virtual ID allocation which is
unrelated to the physical CPU mask.

These issues can be reproduced by running the rseq selftests under a
taskset which excludes CPU 0, e.g.

  taskset -c 10-20 ./run_param_test.sh

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
---
 .../selftests/rseq/basic_percpu_ops_test.c    | 14 ++++++++++--
 tools/testing/selftests/rseq/param_test.c     | 22 ++++++++++++++-----
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/rseq/basic_percpu_ops_test.c b/tools/testing/selftests/rseq/basic_percpu_ops_test.c
index 887542961968..2348d2c20d0a 100644
--- a/tools/testing/selftests/rseq/basic_percpu_ops_test.c
+++ b/tools/testing/selftests/rseq/basic_percpu_ops_test.c
@@ -24,6 +24,11 @@ bool rseq_validate_cpu_id(void)
 {
 	return rseq_mm_cid_available();
 }
+static
+bool rseq_use_cpu_index(void)
+{
+	return false;	/* Use mm_cid */
+}
 #else
 # define RSEQ_PERCPU	RSEQ_PERCPU_CPU_ID
 static
@@ -36,6 +41,11 @@ bool rseq_validate_cpu_id(void)
 {
 	return rseq_current_cpu_raw() >= 0;
 }
+static
+bool rseq_use_cpu_index(void)
+{
+	return true;	/* Use cpu_id as index. */
+}
 #endif
 
 struct percpu_lock_entry {
@@ -274,7 +284,7 @@ void test_percpu_list(void)
 	/* Generate list entries for every usable cpu. */
 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
 	for (i = 0; i < CPU_SETSIZE; i++) {
-		if (!CPU_ISSET(i, &allowed_cpus))
+		if (rseq_use_cpu_index() && !CPU_ISSET(i, &allowed_cpus))
 			continue;
 		for (j = 1; j <= 100; j++) {
 			struct percpu_list_node *node;
@@ -299,7 +309,7 @@ void test_percpu_list(void)
 	for (i = 0; i < CPU_SETSIZE; i++) {
 		struct percpu_list_node *node;
 
-		if (!CPU_ISSET(i, &allowed_cpus))
+		if (rseq_use_cpu_index() && !CPU_ISSET(i, &allowed_cpus))
 			continue;
 
 		while ((node = __percpu_list_pop(&list, i))) {
diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index 20403d58345c..2f37961240ca 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -288,6 +288,11 @@ bool rseq_validate_cpu_id(void)
 {
 	return rseq_mm_cid_available();
 }
+static
+bool rseq_use_cpu_index(void)
+{
+	return false;	/* Use mm_cid */
+}
 # ifdef TEST_MEMBARRIER
 /*
  * Membarrier does not currently support targeting a mm_cid, so
@@ -312,6 +317,11 @@ bool rseq_validate_cpu_id(void)
 {
 	return rseq_current_cpu_raw() >= 0;
 }
+static
+bool rseq_use_cpu_index(void)
+{
+	return true;	/* Use cpu_id as index. */
+}
 # ifdef TEST_MEMBARRIER
 static
 int rseq_membarrier_expedited(int cpu)
@@ -715,7 +725,7 @@ void test_percpu_list(void)
 	/* Generate list entries for every usable cpu. */
 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
 	for (i = 0; i < CPU_SETSIZE; i++) {
-		if (!CPU_ISSET(i, &allowed_cpus))
+		if (rseq_use_cpu_index() && !CPU_ISSET(i, &allowed_cpus))
 			continue;
 		for (j = 1; j <= 100; j++) {
 			struct percpu_list_node *node;
@@ -752,7 +762,7 @@ void test_percpu_list(void)
 	for (i = 0; i < CPU_SETSIZE; i++) {
 		struct percpu_list_node *node;
 
-		if (!CPU_ISSET(i, &allowed_cpus))
+		if (rseq_use_cpu_index() && !CPU_ISSET(i, &allowed_cpus))
 			continue;
 
 		while ((node = __percpu_list_pop(&list, i))) {
@@ -902,7 +912,7 @@ void test_percpu_buffer(void)
 	/* Generate list entries for every usable cpu. */
 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
 	for (i = 0; i < CPU_SETSIZE; i++) {
-		if (!CPU_ISSET(i, &allowed_cpus))
+		if (rseq_use_cpu_index() && !CPU_ISSET(i, &allowed_cpus))
 			continue;
 		/* Worse-case is every item in same CPU. */
 		buffer.c[i].array =
@@ -952,7 +962,7 @@ void test_percpu_buffer(void)
 	for (i = 0; i < CPU_SETSIZE; i++) {
 		struct percpu_buffer_node *node;
 
-		if (!CPU_ISSET(i, &allowed_cpus))
+		if (rseq_use_cpu_index() && !CPU_ISSET(i, &allowed_cpus))
 			continue;
 
 		while ((node = __percpu_buffer_pop(&buffer, i))) {
@@ -1113,7 +1123,7 @@ void test_percpu_memcpy_buffer(void)
 	/* Generate list entries for every usable cpu. */
 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
 	for (i = 0; i < CPU_SETSIZE; i++) {
-		if (!CPU_ISSET(i, &allowed_cpus))
+		if (rseq_use_cpu_index() && !CPU_ISSET(i, &allowed_cpus))
 			continue;
 		/* Worse-case is every item in same CPU. */
 		buffer.c[i].array =
@@ -1160,7 +1170,7 @@ void test_percpu_memcpy_buffer(void)
 	for (i = 0; i < CPU_SETSIZE; i++) {
 		struct percpu_memcpy_buffer_node item;
 
-		if (!CPU_ISSET(i, &allowed_cpus))
+		if (rseq_use_cpu_index() && !CPU_ISSET(i, &allowed_cpus))
 			continue;
 
 		while (__percpu_memcpy_buffer_pop(&buffer, &item, i)) {
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH] selftests/rseq: Do not skip !allowed_cpus for mm_cid
  2024-01-11 15:49 [PATCH] selftests/rseq: Do not skip !allowed_cpus for mm_cid Mathieu Desnoyers
@ 2024-01-22 18:43 ` Shuah Khan
  2024-01-22 18:55   ` Mathieu Desnoyers
  0 siblings, 1 reply; 3+ messages in thread
From: Shuah Khan @ 2024-01-22 18:43 UTC (permalink / raw)
  To: Mathieu Desnoyers, Shuah Khan
  Cc: linux-kernel, Peter Zijlstra, Paul E. McKenney, Boqun Feng, Shuah Khan

On 1/11/24 08:49, Mathieu Desnoyers wrote:
> Indexing with mm_cid is incompatible with skipping disallowed cpumask,
> because concurrency IDs are based on a virtual ID allocation which is
> unrelated to the physical CPU mask.
> 
> These issues can be reproduced by running the rseq selftests under a
> taskset which excludes CPU 0, e.g.
> 
>    taskset -c 10-20 ./run_param_test.sh
> 
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Shuah Khan <shuah@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: "Paul E. McKenney" <paulmck@kernel.org>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> ---

Hi Mathieu,

I applied this to linux-kselftest fixes for the next rc.

Please cc linux-kselftest mailing list on your future patches. This makes
my workflow easier as it relies on patches going to linux-kselftest patchworks
project.

thanks,
-- Shuah


^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH] selftests/rseq: Do not skip !allowed_cpus for mm_cid
  2024-01-22 18:43 ` Shuah Khan
@ 2024-01-22 18:55   ` Mathieu Desnoyers
  0 siblings, 0 replies; 3+ messages in thread
From: Mathieu Desnoyers @ 2024-01-22 18:55 UTC (permalink / raw)
  To: Shuah Khan, Shuah Khan
  Cc: linux-kernel, Peter Zijlstra, Paul E. McKenney, Boqun Feng

On 2024-01-22 13:43, Shuah Khan wrote:
> On 1/11/24 08:49, Mathieu Desnoyers wrote:
>> Indexing with mm_cid is incompatible with skipping disallowed cpumask,
>> because concurrency IDs are based on a virtual ID allocation which is
>> unrelated to the physical CPU mask.
>>
>> These issues can be reproduced by running the rseq selftests under a
>> taskset which excludes CPU 0, e.g.
>>
>>    taskset -c 10-20 ./run_param_test.sh
>>
>> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
>> Cc: Shuah Khan <shuah@kernel.org>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: "Paul E. McKenney" <paulmck@kernel.org>
>> Cc: Boqun Feng <boqun.feng@gmail.com>
>> ---
> 
> Hi Mathieu,
> 
> I applied this to linux-kselftest fixes for the next rc.
> 
> Please cc linux-kselftest mailing list on your future patches. This makes
> my workflow easier as it relies on patches going to linux-kselftest 
> patchworks
> project.

Will do, thanks!

Mathieu

> 
> thanks,
> -- Shuah
> 

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com


^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2024-01-22 18:55 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-01-11 15:49 [PATCH] selftests/rseq: Do not skip !allowed_cpus for mm_cid Mathieu Desnoyers
2024-01-22 18:43 ` Shuah Khan
2024-01-22 18:55   ` Mathieu Desnoyers

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.