On 08/31/2010 04:57 PM, Anton Blanchard wrote: > > 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! Thanks for testing this out. I was able to test this on a 1 TB system and saw memory sysfs creation times go from 10 minutes to a few seconds. It's good to see the difference for a 2 TB system. -Nathan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>