From: Mike Rapoport <rppt@kernel.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Jessica Clarke <jrtc27@jrtc27.com>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
Tony Luck <tony.luck@intel.com>,
linux-ia64@vger.kernel.org, Anatoly Pugachev <matorola@gmail.com>,
Sergei Trofimovich <slyfox@gentoo.org>,
linux-mm@kvack.org, Frank Scheiner <frank.scheiner@web.de>,
Mike Rapoport <rppt@linux.ibm.com>
Subject: Re: [PATCH v5] arch/ia64: Restore arch-specific pgd_offset_k implementation
Date: Fri, 14 Aug 2020 01:21:10 +0300 [thread overview]
Message-ID: <20200813222110.GE752365@kernel.org> (raw)
In-Reply-To: <20200813213631.GQ17456@casper.infradead.org>
On Thu, Aug 13, 2020 at 10:36:31PM +0100, Matthew Wilcox wrote:
> On Thu, Aug 13, 2020 at 11:55:21PM +0300, Mike Rapoport wrote:
> > +/*
> > + * In the kernel's mapped region we know everything is in region number 5, so
> > + * as an optimisation its PGD already points to the area for that region.
>
> Is it actually an optimisation? Are there any benchmarks where this
> makes any difference whatsoever? Or should the comment be closer to
>
> /* ia64 is gratuitously different. Cope with it. */
It better suits arch/ia64/Kconfig ;-)
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 5b4ec80bf586..205cdb91a6d5 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -62,6 +62,7 @@ config IA64
the 32-bit X86 line. The IA-64 Linux project has a home
page at <http://www.linuxia64.org/> and a mailing list at
<linux-ia64@vger.kernel.org>.
+ IA-64 is gratuitously different. Cope with it.
> I might suggest that pgd be changed to be the same as every other pgd
> in the system, and every other architecture.
I did some grepping and got lost in IA-64 assembly, so I agree with
Jessica that it would open a can of worms.
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2020-08-13 22:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-13 20:55 [PATCH v5] arch/ia64: Restore arch-specific pgd_offset_k implementation Mike Rapoport
2020-08-13 21:36 ` Matthew Wilcox
2020-08-13 21:44 ` Jessica Clarke
2020-08-13 22:21 ` Mike Rapoport [this message]
2020-08-17 7:33 ` Mike Rapoport
2020-08-17 16:05 ` Luck, Tony
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=20200813222110.GE752365@kernel.org \
--to=rppt@kernel.org \
--cc=frank.scheiner@web.de \
--cc=glaubitz@physik.fu-berlin.de \
--cc=jrtc27@jrtc27.com \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=matorola@gmail.com \
--cc=rppt@linux.ibm.com \
--cc=slyfox@gentoo.org \
--cc=tony.luck@intel.com \
--cc=willy@infradead.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).