From: "Christopher Friesen" <cfriesen@nortel.com>
To: linuxppc64-dev@ozlabs.org, linuxppc-embedded@ozlabs.org
Subject: modify the cache-inhibit and guard bits from userspace?
Date: Tue, 15 Nov 2005 15:16:57 -0600 [thread overview]
Message-ID: <437A5049.9090308@nortel.com> (raw)
We're running a dual-970 blade, based on a modified 2.6.10.
We have an application that does lots of random data fetches over a
fairly large data set (a few GB) contained entirely in RAM, and the
performance guys think that we may be spending time in unnecessary
hardware prefetches and would like me to provide them a mechanism to
individually specify the cache-inhibited and guard bits from userspace
so that they can try to fine-tune their performance.
What's the most logical way for me to do this? Do I extend mprotect()
to support additional flags?
Has anyone done this before? I didn't find anything in google.
Currently the guard bit seems to only be used for ioremap() and in
__pci_mmap_set_pgprot() if the memory doesn't support write combining.
Thanks,
Chris
next reply other threads:[~2005-11-15 21:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-15 21:16 Christopher Friesen [this message]
2005-11-15 22:38 ` modify the cache-inhibit and guard bits from userspace? Arnd Bergmann
2005-11-15 23:15 ` Christopher Friesen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=437A5049.9090308@nortel.com \
--to=cfriesen@nortel.com \
--cc=linuxppc-embedded@ozlabs.org \
--cc=linuxppc64-dev@ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).