On 10/4/21 1:21 PM, Mike Christie wrote: > The kthread API creates threads that ignore all signals by default so > modules like vhost that will move from that API to kernel_worker will > not be expecting them. This patch adds a worker flag that tells > kernel_worker to setup the task to ignore signals. > > Signed-off-by: Mike Christie <[email protected]> > Acked-by: Christian Brauner <[email protected]> > --- > include/linux/sched/task.h | 1 + > kernel/fork.c | 11 ++++++++++- > 2 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h > index 781abbc1c288..aefa0d221b57 100644 > --- a/include/linux/sched/task.h > +++ b/include/linux/sched/task.h > @@ -21,6 +21,7 @@ struct css_set; > #define KERN_WORKER_IO BIT(0) > #define KERN_WORKER_USER BIT(1) > #define KERN_WORKER_NO_FILES BIT(2) > +#define KERN_WORKER_NO_SIGS BIT(3) > > struct kernel_clone_args { > u64 flags; > diff --git a/kernel/fork.c b/kernel/fork.c > index 3f3fcabffa5f..34d3dca70cfb 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -2555,6 +2555,8 @@ struct task_struct *create_io_thread(int (*fn)(void *), > void *arg, int node) > struct task_struct *kernel_worker(int (*fn)(void *), void *arg, int node, > unsigned long clone_flags, u32 worker_flags) > { > + struct task_struct *tsk; > + > struct kernel_clone_args args = { > .flags = ((lower_32_bits(clone_flags) | CLONE_VM | > CLONE_UNTRACED) & ~CSIGNAL), > @@ -2564,7 +2566,14 @@ struct task_struct *kernel_worker(int (*fn)(void *), > void *arg, int node, > .worker_flags = KERN_WORKER_USER | worker_flags, > }; > > - return copy_process(NULL, 0, node, &args); > + tsk = copy_process(NULL, 0, node, &args); > + if (IS_ERR(tsk)) > + return tsk; > + > + if (worker_flags & KERN_WORKER_NO_SIGS) > + ignore_signals(tsk); > + > + return tsk;
When I originally did it this way, Eric (correctly) pointed out that it's racy. See where it's currently done as part of copy_process(), not after. -- Jens Axboe _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
