On 08/26/2016 04:04 PM, Doug Dumitru wrote: > I took a simple array from stripe_cache_size 256 => 32K and the system > allocated 265 MB of RAM (crude number via free), so this implies that > the stripe cache is 8K per entry. The stripe cache struct appears to > have a bio plus a bunch of other control items in the struct. I am > not sure if it has a statically allocated page, but at 8K it looks > like it does. So I think the minimum/static memory allocated by the > stripe cache is 8K per entry. This "might" also be the maximum, or > the cache size might grow to handle longer requests. This was answered three days ago. Allow me to quote myself: > This is not correct. Parity operations in MD raid4/5/6 operate on 4k > blocks. The stripe cache for an array is a collection of 4k elements > per member device. Chunk size doesn't factor into the cache itself. Phil -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
