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Date: Sat, 27 Sep 2008 20:26:06 -0700
From: Yinghai Lu <yhlu.kernel@...il.com>
To: Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>,
Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, Yinghai Lu <yhlu.kernel@...il.com>
Subject: [PATCH] x86: mtrr_cleanup hole size should be less than half of chunk_size v2
v2: should check with half of range0 size instead of chunk_size
So don't have silly big hole.
in hpa's case we could auto detect instead of adding mtrr_chunk_size in command line
Ingo, please consider to squash this one to previous one
| commit 2313c2793d290a8cc37c428f8622c53f3fe1d6dc
| Author: Yinghai Lu <yhlu.kernel@...il.com>
| Date: Sat Sep 27 00:30:08 2008 -0700
|
| x86: mtrr_cleanup optimization, v2
Signed-off-by: Yinghai Lu <yhlu.kernel@...il.com>
---
arch/x86/kernel/cpu/mtrr/main.c | 74 +++++++++++++++++++++++-----------------
1 file changed, 43 insertions(+), 31 deletions(-)
Index: linux-2.6/arch/x86/kernel/cpu/mtrr/main.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/mtrr/main.c
+++ linux-2.6/arch/x86/kernel/cpu/mtrr/main.c
@@ -992,22 +992,17 @@ range_to_mtrr_with_hole(struct var_mtrr_
/* only cut back, when it is not the last */
if (sizek) {
while (range0_basek + range0_sizek > (basek + sizek)) {
- range0_sizek -= chunk_sizek;
+ if (range0_sizek >= chunk_sizek)
+ range0_sizek -= chunk_sizek;
+ else
+ range0_sizek = 0;
+
if (!range0_sizek)
break;
}
}
- if (range0_sizek) {
- if (debug_print)
- printk(KERN_DEBUG "range0: %016lx - %016lx\n",
- range0_basek<<10,
- (range0_basek + range0_sizek)<<10);
- state->reg = range_to_mtrr(state->reg, range0_basek,
- range0_sizek, MTRR_TYPE_WRBACK);
-
- }
-
+second_try:
range_basek = range0_basek + range0_sizek;
/* one hole in the middle */
@@ -1015,33 +1010,50 @@ range_to_mtrr_with_hole(struct var_mtrr_
second_sizek = range_basek - basek;
if (range0_sizek > state->range_sizek) {
- unsigned long hole_basek, hole_sizek;
/* one hole in middle or at end */
hole_sizek = range0_sizek - state->range_sizek - second_sizek;
- if (hole_sizek) {
- hole_basek = range_basek - hole_sizek - second_sizek;
- if (debug_print)
- printk(KERN_DEBUG "hole: %016lx - %016lx\n",
- hole_basek<<10,
- (hole_basek + hole_sizek)<<10);
- state->reg = range_to_mtrr(state->reg, hole_basek,
- hole_sizek,
- MTRR_TYPE_UNCACHABLE);
+
+ /* hole size should be less than half of range0 size */
+ if (hole_sizek > (range0_sizek >> 1) &&
+ range0_sizek >= chunk_sizek) {
+ range0_sizek -= chunk_sizek;
+ second_sizek = 0;
+ hole_sizek = 0;
+
+ goto second_try;
}
- } else {
+ }
+
+ if (range0_sizek) {
+ if (debug_print)
+ printk(KERN_DEBUG "range0: %016lx - %016lx\n",
+ range0_basek<<10,
+ (range0_basek + range0_sizek)<<10);
+ state->reg = range_to_mtrr(state->reg, range0_basek,
+ range0_sizek, MTRR_TYPE_WRBACK);
+ }
+
+ if (range0_sizek < state->range_sizek) {
/* need to handle left over */
range_sizek = state->range_sizek - range0_sizek;
- if (range_sizek) {
- if (debug_print)
- printk(KERN_DEBUG "range: %016lx - %016lx\n",
- range_basek<<10,
- (range_basek + range_sizek)<<10);
- state->reg = range_to_mtrr(state->reg, range_basek,
- range_sizek,
- MTRR_TYPE_WRBACK);
- }
+ if (debug_print)
+ printk(KERN_DEBUG "range: %016lx - %016lx\n",
+ range_basek<<10,
+ (range_basek + range_sizek)<<10);
+ state->reg = range_to_mtrr(state->reg, range_basek,
+ range_sizek, MTRR_TYPE_WRBACK);
+ }
+
+ if (hole_sizek) {
+ hole_basek = range_basek - hole_sizek - second_sizek;
+ if (debug_print)
+ printk(KERN_DEBUG "hole: %016lx - %016lx\n",
+ hole_basek<<10,
+ (hole_basek + hole_sizek)<<10);
+ state->reg = range_to_mtrr(state->reg, hole_basek,
+ hole_sizek, MTRR_TYPE_UNCACHABLE);
}
return second_sizek;
--
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