A new configuration variable is introduced to activate the use of range lock instead of semaphore to protect per process memory layout.
This range lock is replacing the use of a semaphore for mmap_sem. Currently only available for X86_64 and PPC64 architectures. By default this option is turned off and requires the EXPERT mode since it is not yet complete. Signed-off-by: Laurent Dufour <[email protected]> --- mm/Kconfig | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/mm/Kconfig b/mm/Kconfig index beb7a455915d..955d9a735a49 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -309,6 +309,18 @@ config NEED_BOUNCE_POOL bool default y if TILE && USB_OHCI_HCD +config MEM_RANGE_LOCK + bool "Use range lock for process's memory layout" + default n + depends on EXPERT + depends on MMU + depends on X86_64 || PPC64 + help + Use range lock instead of traditional semaphore to protect per + process memory layout. This is required when dealing with massive + threaded process on very large system (more than 80 cpu threads). + If unsure say n. + config NR_QUICK int depends on QUICKLIST -- 2.7.4
