https://bugzilla.kernel.org/show_bug.cgi?id=71641 --- Comment #8 from Theodore Tso <tytso@xxxxxxx> --- it's clear this isn't going to get performance up to 1.1 GB/s, but I'm curious how much setting JBD2_NR_BATCH changes things at 512 and 1024 and possibly even 2048. Once it no longer maters a difference, if you could do another blktrace, and also gather lock_stat information, that would be useful. To gather lock_stat information, enable CONFIG_LOCK_STAT, and then "echo 0 > /proc/lock_stat" before you start the workload, and then capture the output of /proc/lock_stat after you finish running your workload/benchmark. If you also regather numbers with lock_stat enabled on a stock 3.11 kernel (and also get a /proc/lock_stat report from a stock 3.11 kernel, with and without data=journal), that would be useful. If it turns out that there is some lock contention going on with some of the jbd2 spinlocks, there are some patches queued for 3.15 that I may have to ask you to try (which will mean going to something like 3.14-rc7 plus some additional patches from the ext4 git tree). Thanks for your benchmarking! -- You are receiving this mail because: You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
