On Fri, 17 Feb 2005, Greg Stark wrote:
Oliver Jowett <[EMAIL PROTECTED]> writes:
So Linux is indeed doing a cache flush on fsync
Actually I think the root of the problem was precisely that Linux does not
issue any sort of cache flush commands to drives on fsync.
No, it does. Let's try the simplest test:
for (i = 0; i < LEN; i++) {
write (fd, buf, 512);
if (sync) fsync (fd);
}
with sync = 0 and 1, and you'll see the difference.
There was some talk
on linux-kernel of what how they could take advantage of new ATA features
planned on new SATA drives coming out now to solve this. But they didn't seem
to think it was urgent or worth the performance hit of doing a complete cache
flush.
It was a bit different topic.
Regards,
E.R.
_________________________________________________________________________
Evgeny Rodichev Sternberg Astronomical Institute
email: [EMAIL PROTECTED] Moscow State University
Phone: 007 (095) 939 2383
Fax: 007 (095) 932 8841 http://www.sai.msu.su/~er
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