On Tue, Feb 05, 2008 at 04:24:33PM -0700, Bjorn Helgaas wrote: > On Tuesday 05 February 2008 04:12:32 pm Russ Anderson wrote: > > On Tue, Feb 05, 2008 at 01:21:00PM -0700, Bjorn Helgaas wrote: > > > > > What happens if this alloc fails? > > > > The updated patch will panic is alloc fails. > > I don't know this code well, so I apologize for asking basic > questions. > > Is panic the only choice here? It seems unfriendly to panic > just because we can't successfully add a new CPU. It'd be > nicer to somehow make the addition fail so the new CPU is > just not usable. It wasn't my first choice, but ia64_mca_cpu_init() is void so it's not as simple as returning a failing status. That code was written as part of early boot and if you can't get through boot without running out of memory you have bigger problems. For example, __alloc_bootmem() calls panic if it cannot allocate memory. There is no easy unwind path out of that code. Given that ia64_mca_cpu_init() does not get called in the hot-plug path, the scenario of hot adding a cpu hitting this panic is not possible. If/When the hot-plug code starts calling ia64_mca_cpu_init(), it will be an issue. Thanks, -- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@xxxxxxx - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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