forked from luck/tmp_suning_uos_patched
f441882a52
ARMv6+ processors do not use CONFIG_CPU_USE_DOMAINS and use privileged
ldr/str instructions in copy_{from/to}_user. They are currently
unnecessarily using single ldr/str instructions and can use ldm/stm
instructions instead like memcpy does (but with appropriate fixup
tables).
This speeds up a "dd if=foo of=bar bs=32k" on a tmpfs filesystem by
about 4% on my Cortex-A9.
before:134217728 bytes (128.0MB) copied, 0.543848 seconds, 235.4MB/s
before:134217728 bytes (128.0MB) copied, 0.538610 seconds, 237.6MB/s
before:134217728 bytes (128.0MB) copied, 0.544356 seconds, 235.1MB/s
before:134217728 bytes (128.0MB) copied, 0.544364 seconds, 235.1MB/s
before:134217728 bytes (128.0MB) copied, 0.537130 seconds, 238.3MB/s
before:134217728 bytes (128.0MB) copied, 0.533443 seconds, 240.0MB/s
before:134217728 bytes (128.0MB) copied, 0.545691 seconds, 234.6MB/s
before:134217728 bytes (128.0MB) copied, 0.534695 seconds, 239.4MB/s
before:134217728 bytes (128.0MB) copied, 0.540561 seconds, 236.8MB/s
before:134217728 bytes (128.0MB) copied, 0.541025 seconds, 236.6MB/s
after:134217728 bytes (128.0MB) copied, 0.520445 seconds, 245.9MB/s
after:134217728 bytes (128.0MB) copied, 0.527846 seconds, 242.5MB/s
after:134217728 bytes (128.0MB) copied, 0.519510 seconds, 246.4MB/s
after:134217728 bytes (128.0MB) copied, 0.527231 seconds, 242.8MB/s
after:134217728 bytes (128.0MB) copied, 0.525030 seconds, 243.8MB/s
after:134217728 bytes (128.0MB) copied, 0.524236 seconds, 244.2MB/s
after:134217728 bytes (128.0MB) copied, 0.523659 seconds, 244.4MB/s
after:134217728 bytes (128.0MB) copied, 0.525018 seconds, 243.8MB/s
after:134217728 bytes (128.0MB) copied, 0.519249 seconds, 246.5MB/s
after:134217728 bytes (128.0MB) copied, 0.518527 seconds, 246.9MB/s
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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|---|---|---|
| .. | ||
| ashldi3.S | ||
| ashrdi3.S | ||
| backtrace.S | ||
| bitops.h | ||
| bswapsdi2.S | ||
| call_with_stack.S | ||
| changebit.S | ||
| clear_user.S | ||
| clearbit.S | ||
| copy_from_user.S | ||
| copy_page.S | ||
| copy_template.S | ||
| copy_to_user.S | ||
| csumipv6.S | ||
| csumpartial.S | ||
| csumpartialcopy.S | ||
| csumpartialcopygeneric.S | ||
| csumpartialcopyuser.S | ||
| delay-loop.S | ||
| delay.c | ||
| div64.S | ||
| ecard.S | ||
| findbit.S | ||
| floppydma.S | ||
| getuser.S | ||
| io-acorn.S | ||
| io-readsb.S | ||
| io-readsl.S | ||
| io-readsw-armv3.S | ||
| io-readsw-armv4.S | ||
| io-writesb.S | ||
| io-writesl.S | ||
| io-writesw-armv3.S | ||
| io-writesw-armv4.S | ||
| lib1funcs.S | ||
| lshrdi3.S | ||
| Makefile | ||
| memchr.S | ||
| memcpy.S | ||
| memmove.S | ||
| memset.S | ||
| muldi3.S | ||
| putuser.S | ||
| setbit.S | ||
| strchr.S | ||
| strrchr.S | ||
| testchangebit.S | ||
| testclearbit.S | ||
| testsetbit.S | ||
| uaccess_with_memcpy.c | ||
| ucmpdi2.S | ||
| xor-neon.c | ||