Linux; What is stripe_cache_size and what does it do?

from my understanding the stipe_cache_size is the number of stripe entries in the stripe cache. The stripe entries varies from systems to system but it is mostly controlled by the page size(default of 4096 bytes on linux systems)(https://github.com/torvalds/linux/blob/master/drivers/md/raid5.c#L73 , this file have all the logic of the stripe cache if you'd like to dig deeper) so in a 4 disk RAID5, a stripe_cache_size of 32768 will cost you 512MB of RAM. as far as I know it affect only raid5.

here are 2 documentation references: - https://github.com/torvalds/linux/blob/master/Documentation/md.txt#L603 - https://raid.wiki.kernel.org/index.php/Performance#Some_problem_solving_for_benchmarking