LinuxLists.cc - [PATCH] tools/testing/selftests/livepatch: define max test-syscall processes

2024-05-29 20:20:10

Subject: [PATCH] tools/testing/selftests/livepatch: define max test-syscall processes

Define a maximum allowable number of pids that can be livepatched in
test-syscall.sh as with extremely large machines the output from a
large number of processes overflows the dev/kmsg "expect" buffer in
the "check_result" function and causes a false error.

Reported-by: CKI Project <[email protected]>
Signed-off-by: Ryan Sullivan <[email protected]>
---
tools/testing/selftests/livepatch/test-syscall.sh | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/livepatch/test-syscall.sh b/tools/testing/selftests/livepatch/test-syscall.sh
index b76a881d4013..289eb7d4c4b3 100755
--- a/tools/testing/selftests/livepatch/test-syscall.sh
+++ b/tools/testing/selftests/livepatch/test-syscall.sh
@@ -15,7 +15,10 @@ setup_config

start_test "patch getpid syscall while being heavily hammered"

-for i in $(seq 1 $(getconf _NPROCESSORS_ONLN)); do
+NPROC=$(getconf _NPROCESSORS_ONLN)
+MAXPROC=128
+
+for i in $(seq 1 $(($NPROC < $MAXPROC ? $NPROC : $MAXPROC))); do
./test_klp-call_getpid &
pids[$i]="$!"
done
--
2.44.0

2024-05-29 21:09:26

by Marcos Paulo de Souza

[permalink] [raw]

Subject: Re: [PATCH] tools/testing/selftests/livepatch: define max test-syscall processes

From: [email protected]

On Wed, 29 May 2024 16:19:41 -0400 Ryan Sullivan <[email protected]> wrote:

> Define a maximum allowable number of pids that can be livepatched in
> test-syscall.sh as with extremely large machines the output from a
> large number of processes overflows the dev/kmsg "expect" buffer in
> the "check_result" function and causes a false error.

I believe that 128 threads hammering getpid is good enough :)

Tested-by: Marcos Paulo de Souza <[email protected]>
Reviewed-by: Marcos Paulo de Souza <[email protected]>

>
> Reported-by: CKI Project <[email protected]>
> Signed-off-by: Ryan Sullivan <[email protected]>
> ---
> tools/testing/selftests/livepatch/test-syscall.sh | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/livepatch/test-syscall.sh b/tools/testing/selftests/livepatch/test-syscall.sh
> index b76a881d4013..289eb7d4c4b3 100755
> --- a/tools/testing/selftests/livepatch/test-syscall.sh
> +++ b/tools/testing/selftests/livepatch/test-syscall.sh
> @@ -15,7 +15,10 @@ setup_config
>
> start_test "patch getpid syscall while being heavily hammered"
>
> -for i in $(seq 1 $(getconf _NPROCESSORS_ONLN)); do
> +NPROC=$(getconf _NPROCESSORS_ONLN)
> +MAXPROC=128
> +
> +for i in $(seq 1 $(($NPROC < $MAXPROC ? $NPROC : $MAXPROC))); do
> ./test_klp-call_getpid &
> pids[$i]="$!"
> done
> --
> 2.44.0

2024-05-31 08:42:19

by Petr Mladek

[permalink] [raw]

Subject: Re: [PATCH] tools/testing/selftests/livepatch: define max test-syscall processes

On Wed 2024-05-29 16:19:41, Ryan Sullivan wrote:
> Define a maximum allowable number of pids that can be livepatched in
> test-syscall.sh as with extremely large machines the output from a
> large number of processes overflows the dev/kmsg "expect" buffer in
> the "check_result" function and causes a false error.
>
> Reported-by: CKI Project <[email protected]>
> Signed-off-by: Ryan Sullivan <[email protected]>

Looks reasonable.

Reviewed-by: Petr Mladek <[email protected]>

Best Regards,
Petr

PS: I am going to queue it for 6.11. I will add it into
a pull request for 6.10-rcX if there will be another more
critical fix which would need such a pull request.

2024-05-31 11:05:31

by Miroslav Benes

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Subject: Re: [PATCH] tools/testing/selftests/livepatch: define max test-syscall processes

Hi,

On Wed, 29 May 2024, Ryan Sullivan wrote:

> Define a maximum allowable number of pids that can be livepatched in
> test-syscall.sh as with extremely large machines the output from a
> large number of processes overflows the dev/kmsg "expect" buffer in
> the "check_result" function and causes a false error.
>
> Reported-by: CKI Project <[email protected]>
> Signed-off-by: Ryan Sullivan <[email protected]>

a nit: we usually use just "selftests/livepatch:" prefix in Subject.

Acked-by: Miroslav Benes <[email protected]>

M

2024-06-06 13:54:08

by Ryan Sullivan

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Subject: [PATCH] selftests/livepatch: define max test-syscall processes

2024-06-06 18:28:41

by Marcos Paulo de Souza

[permalink] [raw]

Subject: Re: [PATCH] selftests/livepatch: define max test-syscall processes

On Thu, 2024-06-06 at 09:53 -0400, Ryan Sullivan wrote:
> Define a maximum allowable number of pids that can be livepatched in
> test-syscall.sh as with extremely large machines the output from a
> large number of processes overflows the dev/kmsg "expect" buffer in
> the "check_result" function and causes a false error.
>
> Reported-by: CKI Project <[email protected]>
> Signed-off-by: Ryan Sullivan <[email protected]>

Hi Ryan,

is this the same patch that you sent on ? I couldn't spot any changes,
and you also didn't tagged a different version for this patch.

> ---
> tools/testing/selftests/livepatch/test-syscall.sh | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/livepatch/test-syscall.sh
> b/tools/testing/selftests/livepatch/test-syscall.sh
> index b76a881d4013..289eb7d4c4b3 100755
> --- a/tools/testing/selftests/livepatch/test-syscall.sh
> +++ b/tools/testing/selftests/livepatch/test-syscall.sh
> @@ -15,7 +15,10 @@ setup_config
>
> start_test "patch getpid syscall while being heavily hammered"
>
> -for i in $(seq 1 $(getconf _NPROCESSORS_ONLN)); do
> +NPROC=$(getconf _NPROCESSORS_ONLN)
> +MAXPROC=128
> +
> +for i in $(seq 1 $(($NPROC < $MAXPROC ? $NPROC : $MAXPROC))); do
> ./test_klp-call_getpid &
> pids[$i]="$!"
> done

2024-06-06 18:35:19

by Joel Savitz

[permalink] [raw]

Subject: Re: [PATCH] selftests/livepatch: define max test-syscall processes

On Thu, Jun 6, 2024 at 9:54 AM Ryan Sullivan <[email protected]> wrote:
>
> Define a maximum allowable number of pids that can be livepatched in
> test-syscall.sh as with extremely large machines the output from a
> large number of processes overflows the dev/kmsg "expect" buffer in
> the "check_result" function and causes a false error.
>
> Reported-by: CKI Project <[email protected]>
> Signed-off-by: Ryan Sullivan <[email protected]>
> ---
> tools/testing/selftests/livepatch/test-syscall.sh | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/livepatch/test-syscall.sh b/tools/testing/selftests/livepatch/test-syscall.sh
> index b76a881d4013..289eb7d4c4b3 100755
> --- a/tools/testing/selftests/livepatch/test-syscall.sh
> +++ b/tools/testing/selftests/livepatch/test-syscall.sh
> @@ -15,7 +15,10 @@ setup_config
>
> start_test "patch getpid syscall while being heavily hammered"
>
> -for i in $(seq 1 $(getconf _NPROCESSORS_ONLN)); do
> +NPROC=$(getconf _NPROCESSORS_ONLN)
> +MAXPROC=128
> +
> +for i in $(seq 1 $(($NPROC < $MAXPROC ? $NPROC : $MAXPROC))); do
> ./test_klp-call_getpid &
> pids[$i]="$!"
> done
> --
> 2.44.0
>
>
Acked-by: Joel Savitz <[email protected]>

2024-06-07 08:59:04

by Miroslav Benes

[permalink] [raw]

Subject: Re: [PATCH] selftests/livepatch: define max test-syscall processes

On Thu, 6 Jun 2024, Ryan Sullivan wrote:

> Define a maximum allowable number of pids that can be livepatched in
> test-syscall.sh as with extremely large machines the output from a
> large number of processes overflows the dev/kmsg "expect" buffer in
> the "check_result" function and causes a false error.
>
> Reported-by: CKI Project <[email protected]>
> Signed-off-by: Ryan Sullivan <[email protected]>

Acked-by: Miroslav Benes <[email protected]>

M

2024-06-14 12:53:56

by Petr Mladek

[permalink] [raw]

Subject: Re: [PATCH] selftests/livepatch: define max test-syscall processes

On Thu 2024-06-06 09:53:48, Ryan Sullivan wrote:
> Define a maximum allowable number of pids that can be livepatched in
> test-syscall.sh as with extremely large machines the output from a
> large number of processes overflows the dev/kmsg "expect" buffer in
> the "check_result" function and causes a false error.
>
> Reported-by: CKI Project <[email protected]>
> Signed-off-by: Ryan Sullivan <[email protected]>

JFYI, the patch has been committed into livepatching.git,
branch for-6.11.

Best Regards,
Petr