Hello, On (06/25/15 11:24), Luigi Semenzato wrote: > I looked at this some more and I am not sure that there is any bug, or > other possible tuning. > > While the random-write process runs, iostat -x -k 1 reports these numbers: > > average queue size: around 300 > average write wait: typically 200 to 400 ms, but can be over 1000 ms > average read wait: typically 50 to 100 ms > > (more info at crbug.com/414709) > > The read latency may be enough to explain the jank. In addition, the > browser can do fsyncs, and I think that those will block for a long > time. > > Ionice doesn't seem to make a difference. I suspect that once the > blocks are in the output queue, it's first-come/first-serve. Is this > correct or am I confused? > > We can fix this on the application side but only partially. The OS > version updater can use O_SYNC. The problem is that his can happen in > a number of situations, such as when simply downloading a large file, > and in other code we don't control. > do you use CONFIG_IOSCHED_DEADLINE or CONFIG_IOSCHED_CFQ? -ss -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>