The patch titled
llist: add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG
has been added to the -mm tree. Its filename is
llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: llist: add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG
From: Huang Ying <ying.huang@xxxxxxxxx>
cmpxchg() is widely used by lockless code, including NMI-safe lockless
code. But on some architectures, the cmpxchg() implementation is not
NMI-safe, on these architectures the lockless code may need to a
spin_trylock_irqsave() based implementation.
This patch adds a Kconfig option: ARCH_HAVE_NMI_SAFE_CMPXCHG, so that
NMI-safe lockless code can depend on it or provide different
implementation according to it.
On many architectures, cmpxchg is only NMI-safe for several specific
operand sizes. So, ARCH_HAVE_NMI_SAFE_CMPXCHG define in this patch only
guarantees cmpxchg is NMI-safe for sizeof(unsigned long).
Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
Acked-by: Mike Frysinger <vapier@xxxxxxxxxx>
Acked-by: Paul Mundt <lethal@xxxxxxxxxxxx>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@xxxxxxxxx>
Acked-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Acked-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Mikael Starvik <starvik@xxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Hirokazu Takata <takata@xxxxxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Michal Simek <monstr@xxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Kyle McMartin <kyle@xxxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Chen Liqin <liqin.chen@xxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: Andy Grover <andy.grover@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/Kconfig | 3 +++
arch/alpha/Kconfig | 1 +
arch/avr32/Kconfig | 1 +
arch/frv/Kconfig | 1 +
arch/ia64/Kconfig | 1 +
arch/m68k/Kconfig | 1 +
arch/parisc/Kconfig | 1 +
arch/powerpc/Kconfig | 1 +
arch/s390/Kconfig | 1 +
arch/sh/Kconfig | 1 +
arch/sparc/Kconfig | 1 +
arch/tile/Kconfig | 1 +
arch/x86/Kconfig | 1 +
13 files changed, 15 insertions(+)
diff -puN arch/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/Kconfig
--- a/arch/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/Kconfig
@@ -178,4 +178,7 @@ config HAVE_ARCH_JUMP_LABEL
config HAVE_ARCH_MUTEX_CPU_RELAX
bool
+config ARCH_HAVE_NMI_SAFE_CMPXCHG
+ bool
+
source "kernel/gcov/Kconfig"
diff -puN arch/alpha/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/alpha/Kconfig
--- a/arch/alpha/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/alpha/Kconfig
@@ -7,6 +7,7 @@ config ALPHA
select HAVE_SYSCALL_WRAPPERS
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_DMA_ATTRS
help
The Alpha is a 64-bit general-purpose processor designed and
diff -puN arch/avr32/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/avr32/Kconfig
--- a/arch/avr32/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/avr32/Kconfig
@@ -6,6 +6,7 @@ config AVR32
select HAVE_CLK
select HAVE_OPROFILE
select HAVE_KPROBES
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
help
AVR32 is a high-performance 32-bit RISC microprocessor core,
designed for cost-sensitive embedded applications, with particular
diff -puN arch/frv/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/frv/Kconfig
--- a/arch/frv/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/frv/Kconfig
@@ -5,6 +5,7 @@ config FRV
select HAVE_ARCH_TRACEHOOK
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
config ZONE_DMA
bool
diff -puN arch/ia64/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/ia64/Kconfig
--- a/arch/ia64/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/ia64/Kconfig
@@ -22,6 +22,7 @@ config IA64
select HAVE_KVM
select HAVE_ARCH_TRACEHOOK
select HAVE_DMA_API_DEBUG
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
default y
help
The Itanium Processor Family is Intel's 64-bit successor to
diff -puN arch/m68k/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/m68k/Kconfig
--- a/arch/m68k/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/m68k/Kconfig
@@ -4,6 +4,7 @@ config M68K
select HAVE_AOUT
select HAVE_IDE
select GENERIC_ATOMIC64
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS
config MMU
bool
diff -puN arch/parisc/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/parisc/Kconfig
--- a/arch/parisc/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/parisc/Kconfig
@@ -11,6 +11,7 @@ config PARISC
select BUG
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select GENERIC_ATOMIC64 if !64BIT
select GENERIC_HARDIRQS_NO__DO_IRQ
help
diff -puN arch/powerpc/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/powerpc/Kconfig
--- a/arch/powerpc/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/powerpc/Kconfig
@@ -141,6 +141,7 @@ config PPC
select GENERIC_ATOMIC64 if PPC32
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
diff -puN arch/s390/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/s390/Kconfig
--- a/arch/s390/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/s390/Kconfig
@@ -81,6 +81,7 @@ config S390
select INIT_ALL_POSSIBLE
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_LZMA
diff -puN arch/sh/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/sh/Kconfig
--- a/arch/sh/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/sh/Kconfig
@@ -11,6 +11,7 @@ config SUPERH
select HAVE_DMA_ATTRS
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if (GUSA_RB || CPU_SH4A)
select PERF_USE_VMALLOC
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_BZIP2
diff -puN arch/sparc/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/sparc/Kconfig
--- a/arch/sparc/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/sparc/Kconfig
@@ -50,6 +50,7 @@ config SPARC64
select RTC_DRV_STARFIRE
select HAVE_PERF_EVENTS
select PERF_USE_VMALLOC
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
config ARCH_DEFCONFIG
string
diff -puN arch/tile/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/tile/Kconfig
--- a/arch/tile/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/tile/Kconfig
@@ -104,6 +104,7 @@ config TILE
select GENERIC_FIND_NEXT_BIT
select USE_GENERIC_SMP_HELPERS
select CC_OPTIMIZE_FOR_SIZE
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT
diff -puN arch/x86/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg arch/x86/Kconfig
--- a/arch/x86/Kconfig~llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg
+++ a/arch/x86/Kconfig
@@ -23,6 +23,7 @@ config X86
select HAVE_OPROFILE
select HAVE_PERF_EVENTS
select HAVE_IRQ_WORK
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if !M386
select HAVE_IOREMAP_PROT
select HAVE_KPROBES
select HAVE_MEMBLOCK
_
Patches currently in -mm which might be from ying.huang@xxxxxxxxx are
llist-add-kconfig-option-arch_have_nmi_safe_cmpxchg.patch
llist-lib-add-lock-less-null-terminated-single-list.patch
llist-irq_work-use-llist-in-irq_work.patch
llist-net-rds-replace-xlist-in-net-rds-xlisth-with-llist.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
