On Friday 26 January 2007 19:23, Bill Davidsen wrote:
> Denis Vlasenko wrote:
> > On Thursday 25 January 2007 21:45, Michael Tokarev wrote:
> >> Phillip Susi wrote:
> >>> Denis Vlasenko wrote:
> >>>> You mean "You can use aio_write" ?
> >>> Exactly. You generally don't use O_DIRECT without aio. Combining the
> >>> two is what gives the big win.
> >> Well, it's not only aio. Multithreaded I/O also helps alot -- all this,
> >> say, to utilize a raid array with many spindles.
> >>
> >> But even single-threaded I/O but in large quantities benefits from O_DIRECT
> >> significantly, and I pointed this out before.
> >
> > Which shouldn't be true. There is no fundamental reason why
> > ordinary writes should be slower than O_DIRECT.
> >
> Other than the copy to buffer taking CPU and memory resources.
It is not required by any standard that I know. Kernel can be smarter
and avoid that if it can.
--
vda
-
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/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
