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| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2009-06-14 10:59:32 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-06-14 10:59:32 +0100 |
| commit | 98797a241e28b787b84d308b867ec4c5fe7bbdf8 (patch) | |
| tree | edd39824d91bd8cf33d8903e10ed337611483360 /arch/arm/Kconfig | |
| parent | ca8cbc8391cbd4d6e4304fc6b62682ed93d2b165 (diff) | |
| parent | c626e3f5ca1d95ad2204d3128c26e7678714eb55 (diff) | |
| download | lwn-98797a241e28b787b84d308b867ec4c5fe7bbdf8.tar.gz lwn-98797a241e28b787b84d308b867ec4c5fe7bbdf8.zip | |
Merge branch 'copy_user' of git://git.marvell.com/orion into devel
Diffstat (limited to 'arch/arm/Kconfig')
| -rw-r--r-- | arch/arm/Kconfig | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c857111ab964..3473f8b8ede6 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1091,6 +1091,22 @@ config ALIGNMENT_TRAP correct operation of some network protocols. With an IP-only configuration it is safe to say N, otherwise say Y. +config UACCESS_WITH_MEMCPY + bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user() (EXPERIMENTAL)" + depends on MMU && EXPERIMENTAL + default y if CPU_FEROCEON + help + Implement faster copy_to_user and clear_user methods for CPU + cores where a 8-word STM instruction give significantly higher + memory write throughput than a sequence of individual 32bit stores. + + A possible side effect is a slight increase in scheduling latency + between threads sharing the same address space if they invoke + such copy operations with large buffers. + + However, if the CPU data cache is using a write-allocate mode, + this option is unlikely to provide any performance gain. + endmenu menu "Boot options" |