Re: [PATCH 2 of 4] hotplug-memory: adding non-section-aligned memoryis bad
From: Jeremy Fitzhardinge
Date: Fri Mar 28 2008 - 14:20:09 EST
KAMEZAWA Hiroyuki wrote:
What would happen if I did online_pages(pfn, 1) on each page as I
populate it?
I think (hope) it works well. But it seems no one tries to do that.
Well I had immediate problems because I try to use it under spinlock and
it calls online_pages -> build_all_zonelists -> stop_machine_run. I can
easily rearrange to fix that, but it seems to me that stop_machine_run()
is probably too expensive to call thousands of times (one for each page,
rather than once per section).
I'm just looking at how I can refactor online_pages() into a function
which does the general zone setup stuff, and one for actually onlining
pages. The function of online_pages() would remain unchanged for
existing users, but I could call the pieces separately at the
appropriate times.
J
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/