Mukesh Ojha <quic_mojha@xxxxxxxxxxx> wrote:
> There could be a scenario where there is too much load on a core
> (n number of tasks which is affined) or in a case when multiple
> rproc subsystem is going for a recovery and they queued recovery
> work to one core so even though subsystem are independent there
> recovery will be delayed if one of the subsystem recovery work
> is taking more time in completing.
>
> If we make this queue unbounded, the recovery work could be picked
> on any cpu. This patch try to address this.
>
> Signed-off-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
> ---
> Changes in v3:
> - Add fallback option to go back to earlier path incase recovery wq
> creation fails.
>
> Changes in v2:
> - Removed WQ_HIGHPRI.
> - Updated commit text.
>
> drivers/remoteproc/remoteproc_core.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index c510125..6446c84 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -59,6 +59,7 @@ static int rproc_release_carveout(struct rproc *rproc,
>
> /* Unique indices for remoteproc devices */
> static DEFINE_IDA(rproc_dev_index);
> +static struct workqueue_struct *rproc_recovery_wq;
>
> static const char * const rproc_crash_names[] = {
> [RPROC_MMUFAULT] = "mmufault",
> @@ -2755,8 +2756,11 @@ void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type)
> dev_err(&rproc->dev, "crash detected in %s: type %s\n",
> rproc->name, rproc_crash_to_string(type));
>
> - /* Have a worker handle the error; ensure system is not suspended */
> - queue_work(system_freezable_wq, &rproc->crash_handler);
> + if (rproc_recovery_wq)
> + queue_work(rproc_recovery_wq, &rproc->crash_handler);
> + else
> + queue_work(system_freezable_wq, &rproc->crash_handler);
This is unnecessarily complicated. If you can't create a workqueue you
have bigger problems with the system. Just stick with the new rproc
workqueue.
> +
> }
> EXPORT_SYMBOL(rproc_report_crash);
>
> @@ -2805,6 +2809,11 @@ static void __exit rproc_exit_panic(void)
>
> static int __init remoteproc_init(void)
> {
> + rproc_recovery_wq = alloc_workqueue("rproc_recovery_wq",
> + WQ_UNBOUND | WQ_FREEZABLE, 0);
> + if (!rproc_recovery_wq)
> + pr_err("remoteproc: creation of rproc_recovery_wq failed\n");
Fail the init if you can't create a workqueue.
> +
> rproc_init_sysfs();
> rproc_init_debugfs();
> rproc_init_cdev();
> @@ -2821,6 +2830,8 @@ static void __exit remoteproc_exit(void)
> rproc_exit_panic();
> rproc_exit_debugfs();
> rproc_exit_sysfs();
> + if (rproc_recovery_wq)
> + destroy_workqueue(rproc_recovery_wq);
Will need a fix here too.
-Saravana
> }
> module_exit(remoteproc_exit);
>
> --
> 2.7.4
