Adds Kconfig option for Cross Memory Attach
Subsystems (2)
PATCH 1/1 Adds Kconfig option for Cross Memory Attach
Hi Andrew,
Attached is a patch which you asked for a while back which adds a Kconfig option to allow people who don't want cross memory attach to not have it included in their build.
Regards,
Chris
Signature · 6 lines
[email protected] Signed-off-by: Chris Yeoh <[email protected]> Kconfig | 11 +++++++++++ Makefile | 7 +++++-- 2 files changed, 16 insertions(+), 2 deletions(-)
mm/Kconfig +11 -0
@@ -379,3 +379,14 @@ config CLEANCACHE in a negligible performance hit. If unsure, say Y to enable cleancache + +config CROSS_MEMORY_ATTACH + bool "Cross Memory Support" + depends on MMU + default y + help + Enabling this option adds the system calls process_vm_readv and + process_vm_writev which allow a process with the correct privileges + to directly read from or write to to another process's address space. + See the man page for more details. +
mm/Makefile +5 -2
@@ -5,8 +5,11 @@ mmu-y := nommu.o mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \ mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \ - vmalloc.o pagewalk.o pgtable-generic.o \ - process_vm_access.o + vmalloc.o pagewalk.o pgtable-generic.o + +ifdef CONFIG_CROSS_MEMORY_ATTACH +mmu-$(CONFIG_MMU) += process_vm_access.o +endif obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ maccess.o page_alloc.o page-writeback.o \
Quoted 5 lines · Christopher Yeoh
Hi Andrew,
Attached is a patch which you asked for a while back which adds a
Kconfigoption to allow people who don't want cross memory attach to not have it included in their build.
and it shouldn't be default y.
Linus has written a diatribe on [not] making new options default to y.
Signature · 1 line
~Randy
Quoted 9 lines · On Mon, 23 Apr 2012 08:48:52 -0700 Randy Dunlap <[email protected]> wrote:
Quoted 5 lines · Christopher Yeoh
Hi Andrew,
Attached is a patch which you asked for a while back which adds a
Kconfigoption to allow people who don't want cross memory attach to not have it included in their build.
Quoted 4 lines
and it shouldn't be default y.
Linus has written a diatribe on [not] making new options default to y.
I'm not that fussed, but currently CMA is enabled whether you like it or not. This just allows you to disable it. IIRC there was an exception where a new config option allows you to disable an old feature (although CMA has not been out that long).
Regards,
Chris
Signature · 1 line
[email protected]