On Wed, 2009-10-07 at 15:38 +0800, Wu Fengguang wrote: > plain text document attachment > (writeback-ratelimit-on-dirty-exceeded.patch) > When dirty_exceeded, use ratelimit = ratelimit_pages/8, allowing it to > scale up to 512KB for memory bounty systems. This is more efficient than > the original 8 pages, and won't risk exceeding the dirty limit too much. > > Given the larger ratelimit value, we can safely ignore the low bound > check in sync_writeback_pages. > > dirty_exceeded is more likely to be seen when there are multiple dirty > processes. In which case the lowered ratelimit will help reduce their > overall wait time (latency) in the throttled queue. Don't forget that ratelimit_pages is a per-cpu limit. So the total error on the dirty limit scales with the number of cpus. Other than that, I guess this patch needs numbers ;-) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
