Skip to contentSkip to conversation

x86: memtest: make it a bit faster

PATCH In review Alexander Holler 2 participants 6 messages Nov 9, 2012 – Nov 21, 2012

Subsystems (2)
x86 x86 MM
lore
Share & tools
lore

Alexander Holler

author
#0 lore raw

PATCH 1/1 x86: memtest: make it a bit faster

While implementing the same functionality for arm, I've noticed that memtest does an unnecessary round to zero the memory. Just reversing the order so that the last round writes 0s spares that round.

While there, I've also changed the message if bad memory is found from informational to emergency.

And last I've removed some warnings from checkpatch.

Signed-off-by Alexander Holler <[email protected]>
---
 arch/x86/mm/memtest.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)
arch/x86/mm/memtest.c +8 -13
index c80b9fb..da80083 100644
@@ -9,7 +9,7 @@
 #include <linux/memblock.h>
 
 static u64 patterns[] __initdata = {
-	0,
+	0, /* Has has to be 0 to leave memtest with zeroed memory */
 	0xffffffffffffffffULL,
 	0x5555555555555555ULL,
 	0xaaaaaaaaaaaaaaaaULL,

@@ -30,7 +30,7 @@ static u64 patterns[] __initdata = {
 
 static void __init reserve_bad_mem(u64 pattern, u64 start_bad, u64 end_bad)
 {
-	printk(KERN_INFO "  %016llx bad mem addr %010llx - %010llx reserved\n",
+	pr_emerg("  %016llx bad mem addr %010llx - %010llx reserved\n",
 	       (unsigned long long) pattern,
 	       (unsigned long long) start_bad,
 	       (unsigned long long) end_bad);

@@ -77,7 +77,7 @@ static void __init do_one_pass(u64 pattern, u64 start, u64 end)
 		this_start = clamp_t(phys_addr_t, this_start, start, end);
 		this_end = clamp_t(phys_addr_t, this_end, start, end);
 		if (this_start < this_end) {
-			printk(KERN_INFO "  %010llx - %010llx pattern %016llx\n",
+			pr_info("  %010llx - %010llx pattern %016llx\n",
 			       (unsigned long long)this_start,
 			       (unsigned long long)this_end,
 			       (unsigned long long)cpu_to_be64(pattern));

@@ -91,8 +91,10 @@ static int memtest_pattern __initdata;
 
 static int __init parse_memtest(char *arg)
 {
+	ssize_t ret __always_unused;
+
 	if (arg)
-		memtest_pattern = simple_strtoul(arg, NULL, 0);
+		ret = kstrtoint(arg, 0, &memtest_pattern);
 	else
 		memtest_pattern = ARRAY_SIZE(patterns);
 

@@ -109,16 +111,9 @@ void __init early_memtest(unsigned long start, unsigned long end)
 	if (!memtest_pattern)
 		return;
 
-	printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
-	for (i = 0; i < memtest_pattern; i++) {
+	pr_info("early_memtest: # of tests: %d\n", memtest_pattern);
+	for (i = memtest_pattern-1; i < UINT_MAX; --i) {
 		idx = i % ARRAY_SIZE(patterns);
 		do_one_pass(patterns[idx], start, end);
 	}
-
-	if (idx > 0) {
-		printk(KERN_INFO "early_memtest: wipe out "
-		       "test pattern from memory\n");
-		/* additional test with pattern 0 will do this */
-		do_one_pass(0, start, end);
-	}
 }
Signature · 1 line
1.7.11.7
#1 lore raw
Quoted 8 lines · Alexander Holler

While implementing the same functionality for arm, I've noticed that memtest does an unnecessary round to zero the memory. Just reversing the order so that the last round writes 0s spares that round.

While there, I've also changed the message if bad memory is found from informational to emergency.

And last I've removed some warnings from checkpatch.

Please send these as additional patch.

Signature · 2 lines
Thanks,
//richard
author
#2 lore raw

Am 09.11.2012 15:21, schrieb richard -rw- weinberger:

Quoted 11 lines · Alexander Holler
Quoted 8 lines

While implementing the same functionality for arm, I've noticed that memtest does an unnecessary round to zero the memory. Just reversing the order so that the last round writes 0s spares that round.

While there, I've also changed the message if bad memory is found from informational to emergency.

And last I've removed some warnings from checkpatch.

Please send these as additional patch.

Than it might be better to wait for an answer from some ARM-people.

Maybe it will make sense to move the whole file to mm/ or similar where I could be used and modified for usage by ARM too.

Regards,

Alexander

author
#3 lore raw

Hello,

Am 09.11.2012 15:27, schrieb Alexander Holler:

Quoted 9 lines

Am 09.11.2012 15:21, schrieb richard -rw- weinberger:

Quoted 8 lines · Alexander Holler
Quoted 7 lines

While implementing the same functionality for arm, I've noticed that memtest does an unnecessary round to zero the memory. Just reversing the order so that the last round writes 0s spares that round.

While there, I've also changed the message if bad memory is found from informational to emergency.

Quoted 8 lines
Quoted 3 lines
Quoted 1 line

And last I've removed some warnings from checkpatch.

Please send these as additional patch.

Than it might be better to wait for an answer from some ARM-people.

Maybe it will make sense to move the whole file to mm/ or similar where I could be used and modified for usage by ARM too.

As I don't know if version for ARM (or the move) will ever happen, I've now made 2 patches as requested. They will follow.

Regards,

Alexander

author
#4 lore raw

PATCH 1/2 x86: memtest: checkpatch and emergency warning if memtest fails

I've used the source of memtest.c for a 32bit version (to use with ARM) and checkpatch had some warnings. This patch removes them.

It also changes the message if bad memory was found from warning to emergency.

Signed-off-by Alexander Holler <[email protected]>
---
 arch/x86/mm/memtest.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
arch/x86/mm/memtest.c +6 -4
index c80b9fb..855a6d5 100644
@@ -30,7 +30,7 @@ static u64 patterns[] __initdata = {
 
 static void __init reserve_bad_mem(u64 pattern, u64 start_bad, u64 end_bad)
 {
-	printk(KERN_INFO "  %016llx bad mem addr %010llx - %010llx reserved\n",
+	pr_emerg("  %016llx bad mem addr %010llx - %010llx reserved\n",
 	       (unsigned long long) pattern,
 	       (unsigned long long) start_bad,
 	       (unsigned long long) end_bad);

@@ -77,7 +77,7 @@ static void __init do_one_pass(u64 pattern, u64 start, u64 end)
 		this_start = clamp_t(phys_addr_t, this_start, start, end);
 		this_end = clamp_t(phys_addr_t, this_end, start, end);
 		if (this_start < this_end) {
-			printk(KERN_INFO "  %010llx - %010llx pattern %016llx\n",
+			pr_info("  %010llx - %010llx pattern %016llx\n",
 			       (unsigned long long)this_start,
 			       (unsigned long long)this_end,
 			       (unsigned long long)cpu_to_be64(pattern));

@@ -91,8 +91,10 @@ static int memtest_pattern __initdata;
 
 static int __init parse_memtest(char *arg)
 {
+	ssize_t ret __always_unused;
+
 	if (arg)
-		memtest_pattern = simple_strtoul(arg, NULL, 0);
+		ret = kstrtoint(arg, 0, &memtest_pattern);
 	else
 		memtest_pattern = ARRAY_SIZE(patterns);
 

@@ -109,7 +111,7 @@ void __init early_memtest(unsigned long start, unsigned long end)
 	if (!memtest_pattern)
 		return;
 
-	printk(KERN_INFO "early_memtest: # of tests: %d\n", memtest_pattern);
+	pr_info("early_memtest: # of tests: %d\n", memtest_pattern);
 	for (i = 0; i < memtest_pattern; i++) {
 		idx = i % ARRAY_SIZE(patterns);
 		do_one_pass(patterns[idx], start, end);
Signature · 1 line
1.7.8.6
author
#5 lore raw

PATCH 2/2 x86: memtest: remove unnecessary round to leave memtest with zeroed mem

By just reversing the order memtest is using the test patterns, an additional round to zero the memory is not necessary.

This makes it a bit faster.

Signed-off-by Alexander Holler <[email protected]>
---
 arch/x86/mm/memtest.c |   11 ++---------
 1 files changed, 2 insertions(+), 9 deletions(-)
arch/x86/mm/memtest.c +2 -9
index 855a6d5..da80083 100644
@@ -9,7 +9,7 @@
 #include <linux/memblock.h>
 
 static u64 patterns[] __initdata = {
-	0,
+	0, /* Has has to be 0 to leave memtest with zeroed memory */
 	0xffffffffffffffffULL,
 	0x5555555555555555ULL,
 	0xaaaaaaaaaaaaaaaaULL,

@@ -112,15 +112,8 @@ void __init early_memtest(unsigned long start, unsigned long end)
 		return;
 
 	pr_info("early_memtest: # of tests: %d\n", memtest_pattern);
-	for (i = 0; i < memtest_pattern; i++) {
+	for (i = memtest_pattern-1; i < UINT_MAX; --i) {
 		idx = i % ARRAY_SIZE(patterns);
 		do_one_pass(patterns[idx], start, end);
 	}
-
-	if (idx > 0) {
-		printk(KERN_INFO "early_memtest: wipe out "
-		       "test pattern from memory\n");
-		/* additional test with pattern 0 will do this */
-		do_one_pass(0, start, end);
-	}
 }
Signature · 1 line
1.7.8.6