* [PATCH 3.8-stable] ARM: 7699/1: sched_clock: Add more notrace to prevent
2013-04-07 23:02 [RESEND PATCH 3.8-stable] ARM: EXYNOS: Fix crash on soft reset on EXYNOS5440 Jonghwan Choi
@ 2013-04-25 0:16 ` Jonghwan Choi
2013-04-25 0:26 ` Stephen Boyd
2013-04-25 8:02 ` [PATCH 3.8-stable] ARM: 7690/1: mm: fix CONFIG_LPAE typos Jonghwan Choi
2013-04-30 7:52 ` [PATCH 3.8-stable] lib/int_sqrt.c: optimize square root algorithm Jonghwan Choi
2 siblings, 1 reply; 8+ messages in thread
From: Jonghwan Choi @ 2013-04-25 0:16 UTC (permalink / raw)
To: 'Jonghwan Choi', linux-kernel
Cc: stable, 'Russell King', 'Stephen Boyd'
This patch looks like it should be in the 3.8-stable tree, should we apply
it?
------------------
From: "Stephen Boyd <sboyd@codeaurora.org>"
commit cea15092f098b7018e89f64a5a14bb71955965d5 upstream
cyc_to_sched_clock() is called by sched_clock() and cyc_to_ns()
is called by cyc_to_sched_clock(). I suspect that some compilers
inline both of these functions into sched_clock() and so we've
been getting away without having a notrace marking. It seems that
my compiler isn't inlining cyc_to_sched_clock() though, so I'm
hitting a recursion bug when I enable the function graph tracer,
causing my system to crash. Marking these functions notrace fixes
it. Technically cyc_to_ns() doesn't need the notrace because it's
already marked inline, but let's just add it so that if we ever
remove inline from that function it doesn't blow up.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
---
arch/arm/kernel/sched_clock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
index bd6f56b..59d2adb 100644
--- a/arch/arm/kernel/sched_clock.c
+++ b/arch/arm/kernel/sched_clock.c
@@ -45,12 +45,12 @@ static u32 notrace jiffy_sched_clock_read(void)
static u32 __read_mostly (*read_sched_clock)(void) =
jiffy_sched_clock_read;
-static inline u64 cyc_to_ns(u64 cyc, u32 mult, u32 shift)
+static inline u64 notrace cyc_to_ns(u64 cyc, u32 mult, u32 shift)
{
return (cyc * mult) >> shift;
}
-static unsigned long long cyc_to_sched_clock(u32 cyc, u32 mask)
+static unsigned long long notrace cyc_to_sched_clock(u32 cyc, u32 mask)
{
u64 epoch_ns;
u32 epoch_cyc;
--
1.7.9.5ml
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 3.8-stable] ARM: 7690/1: mm: fix CONFIG_LPAE typos
2013-04-07 23:02 [RESEND PATCH 3.8-stable] ARM: EXYNOS: Fix crash on soft reset on EXYNOS5440 Jonghwan Choi
2013-04-25 0:16 ` [PATCH 3.8-stable] ARM: 7699/1: sched_clock: Add more notrace to prevent Jonghwan Choi
@ 2013-04-25 8:02 ` Jonghwan Choi
2013-04-25 8:20 ` Paul Bolle
2013-04-30 7:52 ` [PATCH 3.8-stable] lib/int_sqrt.c: optimize square root algorithm Jonghwan Choi
2 siblings, 1 reply; 8+ messages in thread
From: Jonghwan Choi @ 2013-04-25 8:02 UTC (permalink / raw)
To: 'Jonghwan Choi', linux-kernel
Cc: stable, 'Paul Bolle', 'Russell King',
'Will Deacon'
This patch looks like it should be in the 3.8-stable tree, should we apply
it?
------------------
From: "Paul Bolle <pebolle@tiscali.nl>"
commit 4e1db26a0b42e2b6e27c05d68adcc01709c2eed2 upstream
CONFIG_LPAE doesn't exist: the correct option is CONFIG_ARM_LPAE, so fix
up the two typos under arch/arm/.
The fix to head.S is slightly scary, but this is just for setting up
an early io-mapping for the serial port when running on a big-endian,
LPAE system. Since these systems don't exist in the wild (at least, I
have no access to one outside of kvmtool, which doesn't provide a serial
port suitable for earlyprintk), then we can revisit the code later if it
causes any problems.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
---
arch/arm/kernel/head.S | 2 +-
arch/arm/kernel/setup.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index e0eb9a1..8bac553 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -267,7 +267,7 @@ __create_page_tables:
addne r6, r6, #1 << SECTION_SHIFT
strne r6, [r3]
-#if defined(CONFIG_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8)
+#if defined(CONFIG_ARM_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8)
sub r4, r4, #4 @ Fixup page table pointer
@ for 64-bit descriptors
#endif
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 3f6cbb2..62ead98 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -524,7 +524,7 @@ int __init arm_add_memory(phys_addr_t start, phys_addr_t
size)
size -= start & ~PAGE_MASK;
bank->start = PAGE_ALIGN(start);
-#ifndef CONFIG_LPAE
+#ifndef CONFIG_ARM_LPAE
if (bank->start + size < bank->start) {
printk(KERN_CRIT "Truncating memory at 0x%08llx to fit in "
"32-bit physical address space\n", (long
long)start);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH 3.8-stable] ARM: 7690/1: mm: fix CONFIG_LPAE typos
2013-04-25 8:02 ` [PATCH 3.8-stable] ARM: 7690/1: mm: fix CONFIG_LPAE typos Jonghwan Choi
@ 2013-04-25 8:20 ` Paul Bolle
2013-04-25 9:01 ` Will Deacon
0 siblings, 1 reply; 8+ messages in thread
From: Paul Bolle @ 2013-04-25 8:20 UTC (permalink / raw)
To: Jonghwan Choi; +Cc: linux-kernel, stable, Russell King, Will Deacon
On Thu, 2013-04-25 at 17:02 +0900, Jonghwan Choi wrote:
> This patch looks like it should be in the 3.8-stable tree, should we apply
> it?
That would be only the setup.c chunk. That fixes a typo introduced in
v3.4 (see commit e5ab85800820edd907d3f43f285e1232f84d5a41
("ARM: 7382/1: mm: truncate memory banks to fit in 4GB space for classic
MMU")). So, if that chunk is deemed appropriate for stable, you could
consider the v3.4.y longterm tree too.
(The typo in head.S was introduced in v3.9-rc2.)
Paul Bolle
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH 3.8-stable] ARM: 7690/1: mm: fix CONFIG_LPAE typos
2013-04-25 8:20 ` Paul Bolle
@ 2013-04-25 9:01 ` Will Deacon
0 siblings, 0 replies; 8+ messages in thread
From: Will Deacon @ 2013-04-25 9:01 UTC (permalink / raw)
To: Paul Bolle
Cc: Jonghwan Choi, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, Russell King
On Thu, Apr 25, 2013 at 09:20:44AM +0100, Paul Bolle wrote:
> On Thu, 2013-04-25 at 17:02 +0900, Jonghwan Choi wrote:
> > This patch looks like it should be in the 3.8-stable tree, should we apply
> > it?
>
> That would be only the setup.c chunk. That fixes a typo introduced in
> v3.4 (see commit e5ab85800820edd907d3f43f285e1232f84d5a41
> ("ARM: 7382/1: mm: truncate memory banks to fit in 4GB space for classic
> MMU")). So, if that chunk is deemed appropriate for stable, you could
> consider the v3.4.y longterm tree too.
Even then, I don't think it's worth backporting this patch. membank->start
and membank->size are phys_addr_t, so with LPAE enabled, this check won't
trigger anyway. The #ifndef is just there for readability really (since the
printk message explicitly refers to 32-bit physical addresses).
So I wouldn't bother with this.
Will
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 3.8-stable] lib/int_sqrt.c: optimize square root algorithm
2013-04-07 23:02 [RESEND PATCH 3.8-stable] ARM: EXYNOS: Fix crash on soft reset on EXYNOS5440 Jonghwan Choi
2013-04-25 0:16 ` [PATCH 3.8-stable] ARM: 7699/1: sched_clock: Add more notrace to prevent Jonghwan Choi
2013-04-25 8:02 ` [PATCH 3.8-stable] ARM: 7690/1: mm: fix CONFIG_LPAE typos Jonghwan Choi
@ 2013-04-30 7:52 ` Jonghwan Choi
2013-04-30 17:32 ` Davidlohr Bueso
2 siblings, 1 reply; 8+ messages in thread
From: Jonghwan Choi @ 2013-04-30 7:52 UTC (permalink / raw)
To: 'Jonghwan Choi', linux-kernel
Cc: stable, 'Davidlohr Bueso', 'Andrew Morton'
This patch looks like it should be in the 3.8-stable tree, should we apply
it?
------------------
From: "Davidlohr Bueso <davidlohr.bueso@hp.com>"
commit 30493cc9dddb68066dcc4878015660fdaa8e0965 upstream
Optimize the current version of the shift-and-subtract (hardware)
algorithm, described by John von Newmann[1] and Guy L Steele.
Iterating 1,000,000 times, perf shows for the current version:
Performance counter stats for './sqrt-curr' (10 runs):
27.170996 task-clock # 0.979 CPUs utilized
( +- 3.19% )
3 context-switches # 0.103 K/sec
( +- 4.76% )
0 cpu-migrations # 0.004 K/sec
( +-100.00% )
104 page-faults # 0.004 M/sec
( +- 0.16% )
64,921,199 cycles # 2.389 GHz
( +- 0.03% )
28,967,789 stalled-cycles-frontend # 44.62% frontend cycles idle
( +- 0.18% )
<not supported> stalled-cycles-backend
104,502,623 instructions # 1.61 insns per cycle
# 0.28 stalled cycles per
insn ( +- 0.00% )
34,088,368 branches # 1254.587 M/sec
( +- 0.00% )
4,901 branch-misses # 0.01% of all branches
( +- 1.32% )
0.027763015 seconds time elapsed
( +- 3.22% )
And for the new version:
Performance counter stats for './sqrt-new' (10 runs):
0.496869 task-clock # 0.519 CPUs utilized
( +- 2.38% )
0 context-switches # 0.000 K/sec
0 cpu-migrations # 0.403 K/sec
( +-100.00% )
104 page-faults # 0.209 M/sec
( +- 0.15% )
590,760 cycles # 1.189 GHz
( +- 2.35% )
395,053 stalled-cycles-frontend # 66.87% frontend cycles idle
( +- 3.67% )
<not supported> stalled-cycles-backend
398,963 instructions # 0.68 insns per cycle
# 0.99 stalled cycles per
insn ( +- 0.39% )
70,228 branches # 141.341 M/sec
( +- 0.36% )
3,364 branch-misses # 4.79% of all branches
( +- 5.45% )
0.000957440 seconds time elapsed
( +- 2.42% )
Furthermore, this saves space in instruction text:
text data bss dec hex filename
111 0 0 111 6f lib/int_sqrt-baseline.o
89 0 0 89 59 lib/int_sqrt.o
[1] http://en.wikipedia.org/wiki/First_Draft_of_a_Report_on_the_EDVAC
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Reviewed-by: Jonathan Gonzalez <jgonzlez@linets.cl>
Tested-by: Jonathan Gonzalez <jgonzlez@linets.cl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
---
lib/int_sqrt.c | 32 +++++++++++++++++++-------------
1 file changed, 19 insertions(+), 13 deletions(-)
diff --git a/lib/int_sqrt.c b/lib/int_sqrt.c
index fc2eeb7..1ef4cc3 100644
--- a/lib/int_sqrt.c
+++ b/lib/int_sqrt.c
@@ -1,3 +1,9 @@
+/*
+ * Copyright (C) 2013 Davidlohr Bueso <davidlohr.bueso@hp.com>
+ *
+ * Based on the shift-and-subtract algorithm for computing integer
+ * square root from Guy L. Steele.
+ */
#include <linux/kernel.h>
#include <linux/export.h>
@@ -10,23 +16,23 @@
*/
unsigned long int_sqrt(unsigned long x)
{
- unsigned long op, res, one;
+ unsigned long b, m, y = 0;
- op = x;
- res = 0;
+ if (x <= 1)
+ return x;
- one = 1UL << (BITS_PER_LONG - 2);
- while (one > op)
- one >>= 2;
+ m = 1UL << (BITS_PER_LONG - 2);
+ while (m != 0) {
+ b = y + m;
+ y >>= 1;
- while (one != 0) {
- if (op >= res + one) {
- op = op - (res + one);
- res = res + 2 * one;
+ if (x >= b) {
+ x -= b;
+ y += m;
}
- res /= 2;
- one /= 4;
+ m >>= 2;
}
- return res;
+
+ return y;
}
EXPORT_SYMBOL(int_sqrt);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 8+ messages in thread