Hello, We are an academic group and we are working on developing a new Linux IO scheduler suitable for SSDs. First we want to find out a way to extract a reproducible trace to use it for comparison between common different IO schedulers. We found out btrecord and btreplay useful for our job but we had problem. First we run our benchmark and blktrace with -queue, and then we use btrecord to record queued requests. Then we used the recorded trace, by running btreplay and simultaneously running blktrace with -issue , to extract dispached requests trace(resulted by queued requests) for the current scheduler. We use the recorded trace of queued requests for other schedulers and we expect to observe different dispatched requests trace for different schedulers, but all traces are same. Moreover as we extracted requests related to our benchmark from trace, resulted by running btreplay, incredibbly we found out that all write requests had been changed to read requests! We want to know that whether our consideration from btrecord and btreplay functionality is correct or not. Thanks in advance, -- To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
