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Tang Junhui committed a728eacbbdd
bcache: add journal statistic Sometimes, Journal takes up a lot of CPU, we need statistics to know what's the journal is doing. So this patch provide some journal statistics: 1) reclaim: how many times the journal try to reclaim resource, usually the journal bucket or/and the pin are exhausted. 2) flush_write: how many times the journal try to flush btree node to cache device, usually the journal bucket are exhausted. 3) retry_flush_write: how many times the journal retry to flush the next btree node, usually the previous tree node have been flushed by other thread. we show these statistic by sysfs interface. Through these statistics We can totally see the status of journal module when the CPU is too high. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>