> Does the (untested, probably does not even build) patch shown below help? > This patch assumes that the kernel was built with CONFIG_PREEMPT=n. > And that I found all the tight loops on the do_sendfile() code path. > I *think* you have. FWIW, it would have been nicer for sendfile(2) and copy_file_range(2) if the do_splice_direct() loop was also killable/interruptible. Users may want to back off from asking the kernel to copy/send a huge file. Thanks, Amir. > > If this is semi-intended, the only option I see is to disable > > something in syzkaller: sched_setattr entirely, or drop CAP_SYS_NICE, > > or ...? Any preference either way? > > Long-running tight loops in the kernel really should contain > cond_resched() or better. > > Thanx, Paul > > ------------------------------------------------------------------------ > > diff --git a/fs/splice.c b/fs/splice.c > index 25212dcca2df..50aa3286764a 100644 > --- a/fs/splice.c > +++ b/fs/splice.c > @@ -985,6 +985,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, > sd->pos = prev_pos + ret; > goto out_release; > } > + cond_resched(); > } > > done: >
