Messages in this thread | | | Subject | RE: [discuss] Re: [patch 3/3] add x86-64 support for memory hot-add II | Date | Fri, 9 Dec 2005 10:36:53 -0800 | From | "Tolentino, Matthew E" <> |
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Andi Kleen <mailto:ak@suse.de> wrote: >> In general SRAT has a hotplug memory bit so it's possible >> to predict how much memory there will be in advance. Since >> the overhead of the kernel page tables should be very >> low I would prefer if you just used instead. >> >> (i.e. instead of extending the kernel mapping preallocate >> the direct mapping and just clear the P bits) >> >> That should be much simpler. > > Looking at it again - accessing SRAT currently relies on the > direct mapping already. Untangling that would be possible, > but require an bt_ioremap which would also add lots of code. > > Ok I retract that objection. I guess your way is better > for now.
Thanks for considering this Andi.
> In addition to the __cpuinit comment > > +if (after_bootmem) spin_unlock(&init_mm.page_table_lock); > > Conditional locking is evil. spinlocking in the boot > case should just work too I think. > > The EXPORTs should be probably EXPORT_SYMBOL_GPL. > > With these changes it would look ok for me.
Excellent points. Thanks for the review and suggestions. I'm testing a revised patch now and will repost in a bit.
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