Re: [PATCH 00/33] Adaptive read-ahead V12

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, May 25, 2006 at 08:44:15AM -0700, Andrew Morton wrote:
These are nice-looking numbers, but one wonders.  If optimising readahead
makes this much difference to postgresql performance then postgresql should
be doing the readahead itself, rather than relying upon the kernel's
ability to guess what the application will be doing in the future.  Because
surely the database can do a better job of that than the kernel.

In this particular case Wu had asked about postgres numbers, so I reported some postgres numbers. You could probably get similar speedups out of postgres by implementing readahead in postgres. OTOH, the kernel patch also gives substantial speedups to thing like cp; the question comes down to whether it's better for every application to implement readahead or for the kernel to do it. (There are, of course, other concerns like maintainability or whether performance degrades in other cases, but I didn't test that. :)

Mike Stone
-
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]
  Powered by Linux