Re: [ext3][kernels >= at least] KDE going comatose when FSis under heavy write load (massive starvation)

From: Mikulas Patocka
Date: Sat Apr 28 2007 - 13:11:56 EST

So perhaps if there's any privileged reads going on then we should limit
writes to a depth of 2 at most, with some timeout mechanism that would

SCSI has a "high priority" bit in the command block, so you can just set it --- but I am not sure how well do disks support it.


gradually allow the deepening of the hardware queue, as long as no
highprio reads come inbetween? With 2 pending requests and even assuming
worst-case seeks the user-visible latency would be on the order of 20-30
msecs, which is at the edge of human perception. The problem comes when
a hardware queue of 32-64 entries starves that one highprio read which
then results in a 2+ seconds latency.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at