Messages in this thread | | | From | Greg Thelen <> | Date | Mon, 8 Nov 2010 14:43:11 -0800 | Subject | Re: [patch 1/4] memcg: use native word to represent dirtyable pages |
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On Mon, Nov 8, 2010 at 2:38 PM, Johannes Weiner <hannes@cmpxchg.org> wrote: > On Mon, Nov 08, 2010 at 02:25:15PM -0800, Greg Thelen wrote: >> Minchan Kim <minchan.kim@gmail.com> writes: >> >> > On Mon, Nov 8, 2010 at 7:14 AM, Johannes Weiner <hannes@cmpxchg.org> wrote: >> >> The memory cgroup dirty info calculation currently uses a signed >> >> 64-bit type to represent the amount of dirtyable memory in pages. >> >> >> >> This can instead be changed to an unsigned word, which will allow the >> >> formula to function correctly with up to 160G of LRU pages on a 32-bit >> Is is really 160G of LRU pages? On 32-bit machine we use a 32 bit >> unsigned page number. With a 4KiB page size, I think that maps 16TiB >> (1<<(32+12)) bytes. Or is there some other limit? > > Yes, the dirty limit we calculate from it :) > > We have to be able to multiply this number by up to 100 (maximum dirty > ratio value) without overflowing.
Duh :) thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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