diff options
author | Alexandre Ghiti <alex@ghiti.fr> | 2019-09-23 15:39:21 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-24 15:54:12 -0700 |
commit | 54c95a11cc1b5e1d578209e027adf5775395dafd (patch) | |
tree | c92ed70d0e17f8728af684b20e583ca1a54b7150 /mm/mmap.c | |
parent | 9035bd29427921cd32d268a830aff78dcafb945b (diff) | |
download | linux-54c95a11cc1b5e1d578209e027adf5775395dafd.tar.bz2 |
riscv: make mmap allocation top-down by default
In order to avoid wasting user address space by using bottom-up mmap
allocation scheme, prefer top-down scheme when possible.
Before:
root@qemuriscv64:~# cat /proc/self/maps
00010000-00016000 r-xp 00000000 fe:00 6389 /bin/cat.coreutils
00016000-00017000 r--p 00005000 fe:00 6389 /bin/cat.coreutils
00017000-00018000 rw-p 00006000 fe:00 6389 /bin/cat.coreutils
00018000-00039000 rw-p 00000000 00:00 0 [heap]
1555556000-155556d000 r-xp 00000000 fe:00 7193 /lib/ld-2.28.so
155556d000-155556e000 r--p 00016000 fe:00 7193 /lib/ld-2.28.so
155556e000-155556f000 rw-p 00017000 fe:00 7193 /lib/ld-2.28.so
155556f000-1555570000 rw-p 00000000 00:00 0
1555570000-1555572000 r-xp 00000000 00:00 0 [vdso]
1555574000-1555576000 rw-p 00000000 00:00 0
1555576000-1555674000 r-xp 00000000 fe:00 7187 /lib/libc-2.28.so
1555674000-1555678000 r--p 000fd000 fe:00 7187 /lib/libc-2.28.so
1555678000-155567a000 rw-p 00101000 fe:00 7187 /lib/libc-2.28.so
155567a000-15556a0000 rw-p 00000000 00:00 0
3fffb90000-3fffbb1000 rw-p 00000000 00:00 0 [stack]
After:
root@qemuriscv64:~# cat /proc/self/maps
00010000-00016000 r-xp 00000000 fe:00 6389 /bin/cat.coreutils
00016000-00017000 r--p 00005000 fe:00 6389 /bin/cat.coreutils
00017000-00018000 rw-p 00006000 fe:00 6389 /bin/cat.coreutils
2de81000-2dea2000 rw-p 00000000 00:00 0 [heap]
3ff7eb6000-3ff7ed8000 rw-p 00000000 00:00 0
3ff7ed8000-3ff7fd6000 r-xp 00000000 fe:00 7187 /lib/libc-2.28.so
3ff7fd6000-3ff7fda000 r--p 000fd000 fe:00 7187 /lib/libc-2.28.so
3ff7fda000-3ff7fdc000 rw-p 00101000 fe:00 7187 /lib/libc-2.28.so
3ff7fdc000-3ff7fe2000 rw-p 00000000 00:00 0
3ff7fe4000-3ff7fe6000 r-xp 00000000 00:00 0 [vdso]
3ff7fe6000-3ff7ffd000 r-xp 00000000 fe:00 7193 /lib/ld-2.28.so
3ff7ffd000-3ff7ffe000 r--p 00016000 fe:00 7193 /lib/ld-2.28.so
3ff7ffe000-3ff7fff000 rw-p 00017000 fe:00 7193 /lib/ld-2.28.so
3ff7fff000-3ff8000000 rw-p 00000000 00:00 0
3fff888000-3fff8a9000 rw-p 00000000 00:00 0 [stack]
[alex@ghiti.fr: v6]
Link: http://lkml.kernel.org/r/20190808061756.19712-15-alex@ghiti.fr
Link: http://lkml.kernel.org/r/20190730055113.23635-15-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Paul Walmsley <paul.walmsley@sifive.com> [arch/riscv]
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
0 files changed, 0 insertions, 0 deletions