Comment 396 for bug 620074

@Jens Axboe: I tried your patch in comment 366 on the 2.6.30 kernel, and it did improve responsiveness in my initial testing. I used to have the problem that the kernel became highly unresponsive on large file copies to the same partition or as soon as it tried to use swap (in 2.6.30-rc3 and earlier), but the unpatched 2.6.30 performs quite reasonably and the patch improved responsiveness further (my unscientific test results are that moving the mouse resulted in much less 'stuttering' after the patch - note that with earlier kernels the mouse would just freeze).

I did though just find a problem where an overnight memory leak caused X to become so unresponsive it couldn't even draw the screen background until I killed the culprit (firefox). This might be unrelated to the patch, ie a problem with swap management, but it does show that the kernel can still become bogged down under high disk I/O.