Re: [PATCH] trim memory not covered by WB MTRRs
- From: Jesse Barnes <jesse.barnes@xxxxxxxxx>
- Date: Tue, 12 Jun 2007 08:29:21 -0700
On Tuesday, June 12, 2007 7:50:08 Pavel Machek wrote:
Hi!
On some machines, buggy BIOSes don't properly setup WB MTRRs to
cover all available RAM, meaning the last few megs (or even gigs)
of memory will be marked uncached. Since Linux tends to allocate
from high memory addresses first, this causes the machine to be
unusably slow as soon as the kernel starts really using memory
(i.e. right around init time).
+ if ((highest_addr >> PAGE_SHIFT) != end_pfn) {
+ printk(KERN_WARNING "***************\n");
+ printk(KERN_WARNING "**** WARNING: likely BIOS bug\n");
+ printk(KERN_WARNING "**** MTRRs don't cover all of "
+ "memory, trimmed %ld pages\n", end_pfn -
+ (highest_addr >> PAGE_SHIFT));
+ printk(KERN_WARNING "***************\n");
+ end_pfn = highest_addr >> PAGE_SHIFT;
Missing 4K of memory is not worth 4K of junk in syslog per boot. Can
you drop the stars and stop shouting?
How missing about 1G of memory? We already discussed this, and Andi and
Venki felt that either a panic or a really obnoxious message was the
way to go...
Jesse
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
- Follow-Ups:
- Re: [PATCH] trim memory not covered by WB MTRRs
- From: Pavel Machek
- Re: [PATCH] trim memory not covered by WB MTRRs
- From: Andi Kleen
- Re: [PATCH] trim memory not covered by WB MTRRs
- References:
- [PATCH] trim memory not covered by WB MTRRs
- From: Jesse Barnes
- Re: [PATCH] trim memory not covered by WB MTRRs
- From: Pavel Machek
- [PATCH] trim memory not covered by WB MTRRs
- Prev by Date: Re: joydev.c and saitek cyborg evo force
- Next by Date: Re: [PATCH 1/18] splice: abstract out actor data
- Previous by thread: Re: [PATCH] trim memory not covered by WB MTRRs
- Next by thread: Re: [PATCH] trim memory not covered by WB MTRRs
- Index(es):
Relevant Pages
|
