20 Oca 2007 Cts 20:03 tarihinde şunları yazmıştınız: > On Sat, Jan 20, 2007 at 07:52:53PM +0200, Ismail Dönmez wrote: > > 20 Oca 2007 Cts 19:45 tarihinde ??unlar?? yazm????t??n??z: > > [...] > > > > > > vaio cartman # hdparm -tT /dev/hda > > > > > > > > /dev/hda: > > > > Timing cached reads: 1576 MB in 2.00 seconds = 788.18 MB/sec > > > > Timing buffered disk reads: 74 MB in 3.01 seconds = 24.55 MB/sec > > > > > > > > > > > > [~]> time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 > > > > 1024+0 records in > > > > 1024+0 records out > > > > 1073741824 bytes (1,1 GB) copied, 77,2809 s, 13,9 MB/s > > > > > > > > real 1m17.482s > > > > user 0m0.003s > > > > sys 0m2.350s > > > > > > That's not bad at all ! I suspect that if your system becomes > > > unresponsive, it's because real writes start when the cache is full. > > > And if you fill 512 MB of RAM with data that you then need to flush on > > > disk at 14 MB/s, it can take about 40 seconds during which it might be > > > difficult to do anything. > > > > > > Try lowering the cache flush starting point to about 10 MB if you want > > > (2% of 512 MB) : > > > > > > # echo 2 >/proc/sys/vm/dirty_ratio > > > # echo 2 >/proc/sys/vm/dirty_background_ratio > > > > After that I get, > > > > [~]> time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 > > 1024+0 records in > > 1024+0 records out > > 1073741824 bytes (1,1 GB) copied, 41,7005 s, 25,7 MB/s > > > > real 0m41.926s > > user 0m0.007s > > sys 0m2.500s > > > > > > not bad! thanks :) > > It is not expected to increase write performance, but it should help > you do something else during that time, or also give more responsiveness > to Ctrl-C. It is possible that you have fast and slow RAM, or that your > video card uses shared memory which slows down some parts of memory > which are not used anymore with those parameters.
Thanks I will try to upgrade RAM but for now at least responsiveness seems to be better. Regards, ismail - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/