LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: William Lee Irwin III <wli@holomorphy.com>
To: Rik van Riel <riel@redhat.com>
Cc: Jack Steiner <steiner@sgi.com>, Anton Blanchard <anton@samba.org>,
	Jes Sorensen <jes@trained-monkey.org>,
	Alexander Viro <viro@math.psu.edu>, Andrew Morton <akpm@osdl.org>,
	linux-kernel@vger.kernel.org, jbarnes@sgi.com
Subject: Re: hash table sizes
Date: Tue, 25 Nov 2003 19:59:53 -0800	[thread overview]
Message-ID: <20031126035953.GF8039@holomorphy.com> (raw)
In-Reply-To: <Pine.LNX.4.44.0311252238140.22777-100000@chimarrao.boston.redhat.com>

On Tue, 25 Nov 2003, Jack Steiner wrote:
>> That was a concern to me too. However, on IA64, all page structs are in
>> the vmalloc region

On Tue, Nov 25, 2003 at 10:39:10PM -0500, Rik van Riel wrote:
> Which you'll probably want to fix eventually.  At least
> PAGE_VALID() doesn't seem to work as advertised currently...
> (occasionally leading to "false positives", with PAGE_VALID()
> saying that a page exists while it really doesn't)

Speaking of which, no one's bothered fixing the X crashes on i386
discontigmem. Untested patch below.


-- wli


diff -prauN linux-2.6.0-test10/include/asm-i386/mmzone.h pfn_valid-2.6.0-test10/include/asm-i386/mmzone.h
--- linux-2.6.0-test10/include/asm-i386/mmzone.h	2003-11-23 17:31:56.000000000 -0800
+++ pfn_valid-2.6.0-test10/include/asm-i386/mmzone.h	2003-11-25 19:54:31.000000000 -0800
@@ -85,13 +85,19 @@ extern struct pglist_data *node_data[];
 })
 #define pmd_page(pmd)		(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
 /*
- * pfn_valid should be made as fast as possible, and the current definition 
- * is valid for machines that are NUMA, but still contiguous, which is what
- * is currently supported. A more generalised, but slower definition would
- * be something like this - mbligh:
- * ( pfn_to_pgdat(pfn) && ((pfn) < node_end_pfn(pfn_to_nid(pfn))) ) 
+ * pfn_valid must absolutely be correct, regardless of speed concerns.
  */ 
-#define pfn_valid(pfn)          ((pfn) < num_physpages)
+#define pfn_valid(pfn)							\
+({									\
+	unsigned long __pfn__ = pfn;					\
+	u8 __nid__ = pfn_to_nid(__pfn__);				\
+	pg_data_t *__pgdat__;						\
+	__pgdat__ = __nid__ < MAX_NUMNODES ? NODE_DATA(__nid__) : NULL;	\
+	__pgdat__ &&							\
+		__pfn__ >= __pgdat__->node_start_pfn &&			\
+		__pfn__ - __pgdat__->node_start_pfn			\
+				< __pgdat__->node_spanned_pages;	\
+})
 
 /*
  * generic node memory support, the following assumptions apply:

  reply	other threads:[~2003-11-26  4:00 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-11-25 13:35 Jes Sorensen
2003-11-25 13:42 ` William Lee Irwin III
2003-11-25 13:54   ` Jes Sorensen
2003-11-25 16:25     ` Thomas Schlichter
2003-11-25 17:52       ` Antonio Vargas
2003-11-25 17:54         ` William Lee Irwin III
2003-11-25 20:48 ` Jack Steiner
2003-11-25 21:07   ` Andrew Morton
2003-11-25 21:14     ` Jesse Barnes
2003-11-25 21:24       ` Andrew Morton
2003-11-26  2:14         ` David S. Miller
2003-11-26  5:27         ` Matt Mackall
2003-11-28 14:15         ` Jes Sorensen
2003-11-28 14:52           ` Jack Steiner
2003-11-28 16:22             ` Jes Sorensen
2003-11-28 19:35               ` Jack Steiner
2003-11-28 21:18                 ` Jörn Engel
2003-12-01  9:46                   ` Jes Sorensen
2003-12-01 21:06     ` Anton Blanchard
2003-12-01 22:57       ` Martin J. Bligh
2003-11-25 21:16   ` Anton Blanchard
2003-11-25 23:11     ` Jack Steiner
2003-11-26  3:39       ` Rik van Riel
2003-11-26  3:59         ` William Lee Irwin III [this message]
2003-11-26  4:25           ` Andrew Morton
2003-11-26  4:23             ` William Lee Irwin III
2003-11-26  5:14           ` Martin J. Bligh
2003-11-26  9:51             ` William Lee Irwin III
2003-11-26 16:17               ` Martin J. Bligh
2003-11-26  7:25       ` Anton Blanchard
2003-11-26  5:53 Zhang, Yanmin
2003-11-29 10:39 Manfred Spraul

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=20031126035953.GF8039@holomorphy.com \
    --to=wli@holomorphy.com \
    --cc=akpm@osdl.org \
    --cc=anton@samba.org \
    --cc=jbarnes@sgi.com \
    --cc=jes@trained-monkey.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=riel@redhat.com \
    --cc=steiner@sgi.com \
    --cc=viro@math.psu.edu \
    --subject='Re: hash table sizes' \
    /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

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).