Al Boldi wrote:
Chris Snook wrote:
At best, reads can be read-ahead and cached, which is why
sequential swap-in sucks less. On-demand reads are as expensive as I/O
can get.
Which means that it should be at least as fast as swap-out, even faster
because write to disk is usually slower than read on modern disks. But
linux currently shows a distinct 2x slowdown for sequential swap-in wrt
swap-out.
That's because writes are faster than reads in moderate
quantities.
The disk caches writes, allowing the OS to write a whole
bunch of data into the disk cache and the disk can optimize
the IO a bit internally.
The same optimization is not possible for reads.
--
Politics is the struggle between those who want to make their country
the best in the world, and those who believe it already is. Each group
calls the other unpatriotic.
-
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]
