mlock() allows a user to control page out of program memory, but this
comes at the cost of faulting in the entire mapping when it is
allocated. For large mappings where the entire area is not necessary
this is not ideal.
This series introduces new flags for mmap() and mlockall() that allow a
user to specify that the covered are should not be paged out, but only
after the memory has been used the first time.
The performance cost of these patches are minimal on the two benchmarks
I have tested (stream and kernbench).
Avg throughput in MB/s from stream using 1000000 element arrays
Test 4.1-rc2 4.1-rc2+lock-on-fault
Copy: 10,979.08 10,917.34
Scale: 11,094.45 11,023.01
Add: 12,487.29 12,388.65
Triad: 12,505.77 12,418.78
Kernbench optimal load
4.1-rc2 4.1-rc2+lock-on-fault
Elapsed Time 71.046 71.324
User Time 62.117 62.352
System Time 8.926 8.969
Context Switches 14531.9 14542.5
Sleeps 14935.9 14939
Eric B Munson (3):
Add flag to request pages are locked after page fault
Add mlockall flag for locking pages on fault
Add tests for lock on fault
arch/alpha/include/uapi/asm/mman.h | 2 +
arch/mips/include/uapi/asm/mman.h | 2 +
arch/parisc/include/uapi/asm/mman.h | 2 +
arch/powerpc/include/uapi/asm/mman.h | 2 +
arch/sparc/include/uapi/asm/mman.h | 2 +
arch/tile/include/uapi/asm/mman.h | 2 +
arch/xtensa/include/uapi/asm/mman.h | 2 +
include/linux/mm.h | 1 +
include/linux/mman.h | 3 +-
include/uapi/asm-generic/mman.h | 2 +
mm/mlock.c | 13 ++-
mm/mmap.c | 4 +-
mm/swap.c | 3 +-
tools/testing/selftests/vm/Makefile | 8 +-
tools/testing/selftests/vm/lock-on-fault.c | 145 ++++++++++++++++++++++++++++
tools/testing/selftests/vm/on-fault-limit.c | 47 +++++++++
tools/testing/selftests/vm/run_vmtests | 23 +++++
17 files changed, 254 insertions(+), 9 deletions(-)
create mode 100644 tools/testing/selftests/vm/lock-on-fault.c
create mode 100644 tools/testing/selftests/vm/on-fault-limit.c
Cc: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Cc: linux-alpha@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-parisc@xxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: sparclinux@xxxxxxxxxxxxxxx
Cc: linux-xtensa@xxxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-api@xxxxxxxxxxxxxxx
--
1.9.1
