Volker Armin Hemmann <[EMAIL PROTECTED]> writes: > swap is incredibly slow on linux. As soon as you are hitting swap, your box > is > dead slow.
It is not just swap which causes the system to become slow. I find that it does the same when running 'emerge sync' and vmstat shows no or only very light swap activity. Yet top shows >80% (often in the upper 95-98%) CPU in 'Wait for I/O'. My hard disks have DMA enabled and 'hdparm -i' shows they are all using UDMA4, so why should the I/O be consuming so much CPU? I would expect it to just start the disk transfers then suspend the process (waiting for the DMA transfer to complete) and allocate the CPU to running another process which is not waiting for disk I/O. -- gentoo-user@gentoo.org mailing list
