2022-03-28 12:13:15

by Jiri Slaby

[permalink] [raw]
Subject: [PATCH] block: restore the old set_task_ioprio() behaviour wrt PF_EXITING

PF_EXITING tasks were silently ignored before the below commits.
Continue doing so. Otherwise python-psutil tests fail:
ERROR: psutil.tests.test_process.TestProcess.test_zombie_process
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1661, in wrapper
return fun(self, *args, **kwargs)
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 2133, in ionice_set
return cext.proc_ioprio_set(self.pid, ioclass, value)
ProcessLookupError: [Errno 3] No such process

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/psutil/tests/test_process.py", line 1313, in test_zombie_process
succeed_or_zombie_p_exc(fun)
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/psutil/tests/test_process.py", line 1288, in succeed_or_zombie_p_exc
return fun()
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/__init__.py", line 792, in ionice
return self._proc.ionice_set(ioclass, value)
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1665, in wrapper
raise NoSuchProcess(self.pid, self._name)
psutil.NoSuchProcess: process no longer exists (pid=2057)

Cc: Christoph Hellwig <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jens Axboe <[email protected]>
Fixes: 5fc11eebb4 (block: open code create_task_io_context in set_task_ioprio)
Fixes: a957b61254 (block: fix error in handling dead task for ioprio setting)
Signed-off-by: Jiri Slaby <[email protected]>
---
block/blk-ioc.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 11f49f78db32..df9cfe4ca532 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -280,7 +280,6 @@ int set_task_ioprio(struct task_struct *task, int ioprio)

task_lock(task);
if (task->flags & PF_EXITING) {
- err = -ESRCH;
kmem_cache_free(iocontext_cachep, ioc);
goto out;
}
@@ -292,7 +291,7 @@ int set_task_ioprio(struct task_struct *task, int ioprio)
task->io_context->ioprio = ioprio;
out:
task_unlock(task);
- return err;
+ return 0;
}
EXPORT_SYMBOL_GPL(set_task_ioprio);

--
2.35.1


2022-03-28 21:05:43

by Jens Axboe

[permalink] [raw]
Subject: Re: [PATCH] block: restore the old set_task_ioprio() behaviour wrt PF_EXITING

On Mon, 28 Mar 2022 10:59:28 +0200, Jiri Slaby wrote:
> PF_EXITING tasks were silently ignored before the below commits.
> Continue doing so. Otherwise python-psutil tests fail:
> ERROR: psutil.tests.test_process.TestProcess.test_zombie_process
> ----------------------------------------------------------------------
> Traceback (most recent call last):
> File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1661, in wrapper
> return fun(self, *args, **kwargs)
> File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 2133, in ionice_set
> return cext.proc_ioprio_set(self.pid, ioclass, value)
> ProcessLookupError: [Errno 3] No such process
>
> [...]

Applied, thanks!

[1/1] block: restore the old set_task_ioprio() behaviour wrt PF_EXITING
commit: 15583a563cd5a7358e975599b7de7caacd9e9ce9

Best regards,
--
Jens Axboe


2022-03-28 22:14:26

by Jan Kara

[permalink] [raw]
Subject: Re: [PATCH] block: restore the old set_task_ioprio() behaviour wrt PF_EXITING

On Mon 28-03-22 10:59:28, Jiri Slaby wrote:
> PF_EXITING tasks were silently ignored before the below commits.
> Continue doing so. Otherwise python-psutil tests fail:
> ERROR: psutil.tests.test_process.TestProcess.test_zombie_process
> ----------------------------------------------------------------------
> Traceback (most recent call last):
> File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1661, in wrapper
> return fun(self, *args, **kwargs)
> File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 2133, in ionice_set
> return cext.proc_ioprio_set(self.pid, ioclass, value)
> ProcessLookupError: [Errno 3] No such process
>
> During handling of the above exception, another exception occurred:
>
> Traceback (most recent call last):
> File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/psutil/tests/test_process.py", line 1313, in test_zombie_process
> succeed_or_zombie_p_exc(fun)
> File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/psutil/tests/test_process.py", line 1288, in succeed_or_zombie_p_exc
> return fun()
> File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/__init__.py", line 792, in ionice
> return self._proc.ionice_set(ioclass, value)
> File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1665, in wrapper
> raise NoSuchProcess(self.pid, self._name)
> psutil.NoSuchProcess: process no longer exists (pid=2057)
>
> Cc: Christoph Hellwig <[email protected]>
> Cc: Jan Kara <[email protected]>
> Cc: Jens Axboe <[email protected]>
> Fixes: 5fc11eebb4 (block: open code create_task_io_context in set_task_ioprio)
> Fixes: a957b61254 (block: fix error in handling dead task for ioprio setting)
> Signed-off-by: Jiri Slaby <[email protected]>

OK, as much as I find it disputable what ioprio_set() should be doing for
PF_EXITTING task, I guess there's no harm in maintaining the old behavior and
just ignoring the call. So feel free to add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
> block/blk-ioc.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/block/blk-ioc.c b/block/blk-ioc.c
> index 11f49f78db32..df9cfe4ca532 100644
> --- a/block/blk-ioc.c
> +++ b/block/blk-ioc.c
> @@ -280,7 +280,6 @@ int set_task_ioprio(struct task_struct *task, int ioprio)
>
> task_lock(task);
> if (task->flags & PF_EXITING) {
> - err = -ESRCH;
> kmem_cache_free(iocontext_cachep, ioc);
> goto out;
> }
> @@ -292,7 +291,7 @@ int set_task_ioprio(struct task_struct *task, int ioprio)
> task->io_context->ioprio = ioprio;
> out:
> task_unlock(task);
> - return err;
> + return 0;
> }
> EXPORT_SYMBOL_GPL(set_task_ioprio);
>
> --
> 2.35.1
>
--
Jan Kara <[email protected]>
SUSE Labs, CR

2022-03-29 11:30:21

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] block: restore the old set_task_ioprio() behaviour wrt PF_EXITING

> task_lock(task);
> if (task->flags & PF_EXITING) {
> - err = -ESRCH;
> kmem_cache_free(iocontext_cachep, ioc);
> goto out;

Please add a commnt here why we are not returning an error, otherwise
this is just getting "fixed" over and over again.