* [PATCH] core: fix typo in percpu read_mostly section
@ 2014-06-23 18:16 Filipe Brandenburger
2014-07-01 19:11 ` Filipe Brandenburger
0 siblings, 1 reply; 3+ messages in thread
From: Filipe Brandenburger @ 2014-06-23 18:16 UTC (permalink / raw)
To: Shaohua Li, Eric Dumazet, H. Peter Anvin, Andi Kleen
Cc: Zhengyu He, linux-kernel, Filipe Brandenburger
From: Zhengyu He <hzy@google.com>
This fixes a typo that named the read_mostly section of percpu as
readmostly. It works fine with SMP because the linker script specifies
.data..percpu..readmostly. However, UP kernel builds don't have percpu
sections defined and the non-percpu version of the section is called
data..read_mostly, so .data..readmostly will float around and may break
things unexpectedly.
Looking at the original change that introduced data..percpu..readmostly
(commit c957ef2c59e952803766ddc22e89981ab534606f), it looks like this
was the original intention.
Tested: Built UP kernel and confirmed the sections got merged.
- Before the patch:
$ objdump -h vmlinux.o | grep '\.data\.\.read.*mostly'
38 .data..read_mostly 00004418 0000000000000000 0000000000000000 00431ac0 2**6
50 .data..readmostly 00000014 0000000000000000 0000000000000000 00444000 2**3
- After the patch:
$ objdump -h vmlinux.o | grep '\.data\.\.read.*mostly'
38 .data..read_mostly 00004438 0000000000000000 0000000000000000 00431ac0 2**6
Signed-off-by: Zhengyu He <hzy@google.com>
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
---
include/asm-generic/vmlinux.lds.h | 2 +-
include/linux/percpu-defs.h | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 471ba48c7ae4..c1c0b0cf39b4 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -693,7 +693,7 @@
. = ALIGN(PAGE_SIZE); \
*(.data..percpu..page_aligned) \
. = ALIGN(cacheline); \
- *(.data..percpu..readmostly) \
+ *(.data..percpu..read_mostly) \
. = ALIGN(cacheline); \
*(.data..percpu) \
*(.data..percpu..shared_aligned) \
diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index a5fc7d01aad6..dec01d6c3f80 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -146,10 +146,10 @@
* Declaration/definition used for per-CPU variables that must be read mostly.
*/
#define DECLARE_PER_CPU_READ_MOSTLY(type, name) \
- DECLARE_PER_CPU_SECTION(type, name, "..readmostly")
+ DECLARE_PER_CPU_SECTION(type, name, "..read_mostly")
#define DEFINE_PER_CPU_READ_MOSTLY(type, name) \
- DEFINE_PER_CPU_SECTION(type, name, "..readmostly")
+ DEFINE_PER_CPU_SECTION(type, name, "..read_mostly")
/*
* Intermodule exports for per-CPU variables. sparse forgets about
--
2.0.0.526.g5318336
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] core: fix typo in percpu read_mostly section
2014-06-23 18:16 [PATCH] core: fix typo in percpu read_mostly section Filipe Brandenburger
@ 2014-07-01 19:11 ` Filipe Brandenburger
2014-07-01 20:46 ` Tejun Heo
0 siblings, 1 reply; 3+ messages in thread
From: Filipe Brandenburger @ 2014-07-01 19:11 UTC (permalink / raw)
To: Tejun Heo, Christoph Lameter
Cc: Eric Dumazet, H. Peter Anvin, Andi Kleen, Zhengyu He,
Greg Thelen, linux-arch, linux-kernel, Filipe Brandenburger
From: Zhengyu He <hzy@google.com>
This fixes a typo that named the read_mostly section of percpu as
readmostly. It works fine with SMP because the linker script specifies
.data..percpu..readmostly. However, UP kernel builds don't have percpu
sections defined and the non-percpu version of the section is called
data..read_mostly, so .data..readmostly will float around and may break
things unexpectedly.
Looking at the original change that introduced data..percpu..readmostly
(commit c957ef2c59e952803766ddc22e89981ab534606f), it looks like this
was the original intention.
Tested: Built UP kernel and confirmed the sections got merged.
- Before the patch:
$ objdump -h vmlinux.o | grep '\.data\.\.read.*mostly'
38 .data..read_mostly 00004418 0000000000000000 0000000000000000 00431ac0 2**6
50 .data..readmostly 00000014 0000000000000000 0000000000000000 00444000 2**3
- After the patch:
$ objdump -h vmlinux.o | grep '\.data\.\.read.*mostly'
38 .data..read_mostly 00004438 0000000000000000 0000000000000000 00431ac0 2**6
Signed-off-by: Zhengyu He <hzy@google.com>
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
---
include/asm-generic/vmlinux.lds.h | 2 +-
include/linux/percpu-defs.h | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 471ba48c7ae4..c1c0b0cf39b4 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -693,7 +693,7 @@
. = ALIGN(PAGE_SIZE); \
*(.data..percpu..page_aligned) \
. = ALIGN(cacheline); \
- *(.data..percpu..readmostly) \
+ *(.data..percpu..read_mostly) \
. = ALIGN(cacheline); \
*(.data..percpu) \
*(.data..percpu..shared_aligned) \
diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index a5fc7d01aad6..dec01d6c3f80 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -146,10 +146,10 @@
* Declaration/definition used for per-CPU variables that must be read mostly.
*/
#define DECLARE_PER_CPU_READ_MOSTLY(type, name) \
- DECLARE_PER_CPU_SECTION(type, name, "..readmostly")
+ DECLARE_PER_CPU_SECTION(type, name, "..read_mostly")
#define DEFINE_PER_CPU_READ_MOSTLY(type, name) \
- DEFINE_PER_CPU_SECTION(type, name, "..readmostly")
+ DEFINE_PER_CPU_SECTION(type, name, "..read_mostly")
/*
* Intermodule exports for per-CPU variables. sparse forgets about
--
2.0.0.526.g5318336
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] core: fix typo in percpu read_mostly section
2014-07-01 19:11 ` Filipe Brandenburger
@ 2014-07-01 20:46 ` Tejun Heo
0 siblings, 0 replies; 3+ messages in thread
From: Tejun Heo @ 2014-07-01 20:46 UTC (permalink / raw)
To: Filipe Brandenburger
Cc: Christoph Lameter, Eric Dumazet, H. Peter Anvin, Andi Kleen,
Zhengyu He, Greg Thelen, linux-arch, linux-kernel
On Tue, Jul 01, 2014 at 12:11:47PM -0700, Filipe Brandenburger wrote:
> From: Zhengyu He <hzy@google.com>
>
> This fixes a typo that named the read_mostly section of percpu as
> readmostly. It works fine with SMP because the linker script specifies
> .data..percpu..readmostly. However, UP kernel builds don't have percpu
> sections defined and the non-percpu version of the section is called
> data..read_mostly, so .data..readmostly will float around and may break
> things unexpectedly.
>
> Looking at the original change that introduced data..percpu..readmostly
> (commit c957ef2c59e952803766ddc22e89981ab534606f), it looks like this
> was the original intention.
>
> Tested: Built UP kernel and confirmed the sections got merged.
>
> - Before the patch:
> $ objdump -h vmlinux.o | grep '\.data\.\.read.*mostly'
> 38 .data..read_mostly 00004418 0000000000000000 0000000000000000 00431ac0 2**6
> 50 .data..readmostly 00000014 0000000000000000 0000000000000000 00444000 2**3
>
> - After the patch:
> $ objdump -h vmlinux.o | grep '\.data\.\.read.*mostly'
> 38 .data..read_mostly 00004438 0000000000000000 0000000000000000 00431ac0 2**6
>
> Signed-off-by: Zhengyu He <hzy@google.com>
> Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Applied to percpu/for-3.16-fixes.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-07-01 20:46 UTC | newest]
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2014-06-23 18:16 [PATCH] core: fix typo in percpu read_mostly section Filipe Brandenburger
2014-07-01 19:11 ` Filipe Brandenburger
2014-07-01 20:46 ` Tejun Heo
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