Messages in this thread | | | Date | Wed, 1 Sep 2010 07:57:45 +1000 | From | Anton Blanchard <> | Subject | Re: [PATCH 0/8] v5 De-couple sysfs memory directories from memory sections |
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Hi Nathan,
> This set of patches de-couples the idea that there is a single > directory in sysfs for each memory section. The intent of the > patches is to reduce the number of sysfs directories created to > resolve a boot-time performance issue. On very large systems > boot time are getting very long (as seen on powerpc hardware) > due to the enormous number of sysfs directories being created. > On a system with 1 TB of memory we create ~63,000 directories. > For even larger systems boot times are being measured in hours. > > This set of patches allows for each directory created in sysfs > to cover more than one memory section. The default behavior for > sysfs directory creation is the same, in that each directory > represents a single memory section. A new file 'end_phys_index' > in each directory contains the physical_id of the last memory > section covered by the directory so that users can easily > determine the memory section range of a directory.
I tested this on a POWER7 with 2TB memory and the boot time improved from greater than 6 hours (I gave up), to under 5 minutes. Nice!
Tested-by: Anton Blanchard <anton@samba.org>
Anton
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