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Message-Id: <20070607172050.ead923b4.akpm@linux-foundation.org>
Date: Thu, 7 Jun 2007 17:20:50 -0700
From: Andrew Morton <akpm@...ux-foundation.org>
To: Jesse Barnes <jesse.barnes@...el.com>
Cc: Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org,
Justin Piszcz <jpiszcz@...idpixels.com>,
"Eric W. Biederman" <ebiederm@...ssion.com>
Subject: Re: [PATCH] trim memory not covered by WB MTRRs
On Wed, 6 Jun 2007 12:29:23 -0700
Jesse Barnes <jesse.barnes@...el.com> wrote:
> --- a/arch/i386/kernel/cpu/mtrr/if.c
> +++ b/arch/i386/kernel/cpu/mtrr/if.c
> @@ -12,7 +12,7 @@
> #include "mtrr.h"
>
> /* RED-PEN: this is accessed without any locking */
> -extern unsigned int *usage_table;
> +extern unsigned int usage_table[];
>
>
> --- a/arch/i386/kernel/cpu/mtrr/main.c
> +++ b/arch/i386/kernel/cpu/mtrr/main.c
> @@ -47,7 +47,7 @@
>
> u32 num_var_ranges = 0;
>
> -unsigned int *usage_table;
> +unsigned int usage_table[NUM_VAR_RANGES];
> static DEFINE_MUTEX(mtrr_mutex);
didn't it feel all dirty when you had to do that?
From: Andrew Morton <akpm@...ux-foundation.org>
- Move the declaration into a header file
- "usage_table" is a dumb name for an mtrr-specific kernel-wide identifier.
There appear to beseveral other poorly-chosen identifiers in mtrr.
Cc: Andi Kleen <ak@...e.de>
Cc: Jesse Barnes <jesse.barnes@...el.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
---
arch/i386/kernel/cpu/mtrr/if.c | 8 ++------
arch/i386/kernel/cpu/mtrr/main.c | 17 +++++++++--------
arch/i386/kernel/cpu/mtrr/mtrr.h | 2 ++
3 files changed, 13 insertions(+), 14 deletions(-)
diff -puN arch/i386/kernel/cpu/mtrr/if.c~i386-x86_64-trim-memory-not-covered-by-wb-mtrrs-fix arch/i386/kernel/cpu/mtrr/if.c
--- a/arch/i386/kernel/cpu/mtrr/if.c~i386-x86_64-trim-memory-not-covered-by-wb-mtrrs-fix
+++ a/arch/i386/kernel/cpu/mtrr/if.c
@@ -11,10 +11,6 @@
#include <asm/mtrr.h>
#include "mtrr.h"
-/* RED-PEN: this is accessed without any locking */
-extern unsigned int usage_table[];
-
-
#define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
static const char *const mtrr_strings[MTRR_NUM_TYPES] =
@@ -396,7 +392,7 @@ static int mtrr_seq_show(struct seq_file
for (i = 0; i < max; i++) {
mtrr_if->get(i, &base, &size, &type);
if (size == 0)
- usage_table[i] = 0;
+ mtrr_usage_table[i] = 0;
else {
if (size < (0x100000 >> PAGE_SHIFT)) {
/* less than 1MB */
@@ -410,7 +406,7 @@ static int mtrr_seq_show(struct seq_file
len += seq_printf(seq,
"reg%02i: base=0x%05lx000 (%4luMB), size=%4lu%cB: %s, count=%d\n",
i, base, base >> (20 - PAGE_SHIFT), size, factor,
- mtrr_attrib_to_str(type), usage_table[i]);
+ mtrr_attrib_to_str(type), mtrr_usage_table[i]);
}
}
return 0;
diff -puN arch/i386/kernel/cpu/mtrr/main.c~i386-x86_64-trim-memory-not-covered-by-wb-mtrrs-fix arch/i386/kernel/cpu/mtrr/main.c
--- a/arch/i386/kernel/cpu/mtrr/main.c~i386-x86_64-trim-memory-not-covered-by-wb-mtrrs-fix
+++ a/arch/i386/kernel/cpu/mtrr/main.c
@@ -47,7 +47,7 @@
u32 num_var_ranges = 0;
-unsigned int usage_table[NUM_VAR_RANGES];
+unsigned int mtrr_usage_table[NUM_VAR_RANGES];
static DEFINE_MUTEX(mtrr_mutex);
u64 size_or_mask, size_and_mask;
@@ -127,7 +127,7 @@ static void __init init_table(void)
max = num_var_ranges;
for (i = 0; i < max; i++)
- usage_table[i] = 1;
+ mtrr_usage_table[i] = 1;
}
struct set_mtrr_data {
@@ -381,7 +381,7 @@ int mtrr_add_page(unsigned long base, un
goto out;
}
if (increment)
- ++usage_table[i];
+ ++mtrr_usage_table[i];
error = i;
goto out;
}
@@ -390,12 +390,13 @@ int mtrr_add_page(unsigned long base, un
if (i >= 0) {
set_mtrr(i, base, size, type);
if (likely(replace < 0))
- usage_table[i] = 1;
+ mtrr_usage_table[i] = 1;
else {
- usage_table[i] = usage_table[replace] + !!increment;
+ mtrr_usage_table[i] = mtrr_usage_table[replace] +
+ !!increment;
if (unlikely(replace != i)) {
set_mtrr(replace, 0, 0, 0);
- usage_table[replace] = 0;
+ mtrr_usage_table[replace] = 0;
}
}
} else
@@ -525,11 +526,11 @@ int mtrr_del_page(int reg, unsigned long
printk(KERN_WARNING "mtrr: MTRR %d not used\n", reg);
goto out;
}
- if (usage_table[reg] < 1) {
+ if (mtrr_usage_table[reg] < 1) {
printk(KERN_WARNING "mtrr: reg: %d has count=0\n", reg);
goto out;
}
- if (--usage_table[reg] < 1)
+ if (--mtrr_usage_table[reg] < 1)
set_mtrr(reg, 0, 0, 0);
error = reg;
out:
diff -puN arch/i386/kernel/cpu/mtrr/mtrr.h~i386-x86_64-trim-memory-not-covered-by-wb-mtrrs-fix arch/i386/kernel/cpu/mtrr/mtrr.h
--- a/arch/i386/kernel/cpu/mtrr/mtrr.h~i386-x86_64-trim-memory-not-covered-by-wb-mtrrs-fix
+++ a/arch/i386/kernel/cpu/mtrr/mtrr.h
@@ -97,3 +97,5 @@ void mtrr_state_warn(void);
const char *mtrr_attrib_to_str(int x);
void mtrr_wrmsr(unsigned, unsigned, unsigned);
+/* RED-PEN: this is accessed without any locking */
+extern unsigned int mtrr_usage_table[];
_
-
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