Messages in this thread | | | Date | Fri, 27 Oct 2006 10:09:51 -0700 | From | Greg KH <> | Subject | Re: + drivers-wait-for-threaded-probes-between-initcall-levels.patch added to -mm tree |
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On Thu, Oct 26, 2006 at 10:09:39AM +0200, Cornelia Huck wrote: > On Wed, 25 Oct 2006 19:12:01 -0700, > akpm@osdl.org wrote: > > > Subject: drivers: wait for threaded probes between initcall levels > > From: Andrew Morton <akpm@osdl.org> > > > > The multithreaded-probing code has a problem: after one initcall level (eg, > > core_initcall) has been processed, we will then start processing the next > > level (postcore_initcall) while the kernel threads which are handling > > core_initcall are still executing. This breaks the guarantees which the > > layered initcalls previously gave us. > > > > IOW, we want to be multithreaded _within_ an initcall level, but not between > > different levels. > > > > Fix that up by causing the probing code to wait for all outstanding probes at > > one level to complete before we start processing the next level. > > > > Cc: Greg KH <greg@kroah.com> > > Signed-off-by: Andrew Morton <akpm@osdl.org> > > Makes a lot of sense. I guess we could also get rid of > driver_probe_done() in prepare_namespace() with this patch... > > > > +#ifdef CONFIG_PCI_MULTITHREAD_PROBE > > +static int __init wait_for_probes(void) > > +{ > > + DEFINE_WAIT(wait); > > + > > + if (!atomic_read(&probe_count)) > > + return 0; > > + printk(KERN_INFO "%s: waiting for %d threads\n", __FUNCTION__, > > + atomic_read(&probe_count)); > > + while (atomic_read(&probe_count)) { > > + prepare_to_wait(&probe_waitqueue, &wait, TASK_UNINTERRUPTIBLE); > > + if (atomic_read(&probe_count)) > > + schedule(); > > + } > > + finish_wait(&probe_waitqueue, &wait); > > + return 0; > > +} > > + > > +core_initcall_sync(wait_for_probes); > > +postcore_initcall_sync(wait_for_probes); > > +arch_initcall_sync(wait_for_probes); > > +subsys_initcall_sync(wait_for_probes); > > +fs_initcall_sync(wait_for_probes); > > +device_initcall_sync(wait_for_probes); > > +late_initcall_sync(wait_for_probes); > > +#endif > > ...if we get rid of this #ifdef.
Yeah, let me play with this a bit, along with your proposed change, I think it can be cleaned up to be a little more cleaner.
thanks,
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