e888d7facd
delay_tsc needs rdtsc_barrier to provide proper delay. Output from a test driver using hpet to cross check delay provided by udelay(). Before: [ 86.794363] Expected delay 5us actual 4679ns [ 87.154362] Expected delay 5us actual 698ns [ 87.514162] Expected delay 5us actual 4539ns [ 88.653716] Expected delay 5us actual 4539ns [ 94.664106] Expected delay 10us actual 9638ns [ 95.049351] Expected delay 10us actual 10126ns [ 95.416110] Expected delay 10us actual 9568ns [ 95.799216] Expected delay 10us actual 9638ns [ 103.624104] Expected delay 10us actual 9707ns [ 104.020619] Expected delay 10us actual 768ns [ 104.419951] Expected delay 10us actual 9707ns After: [ 50.983320] Expected delay 5us actual 5587ns [ 51.261807] Expected delay 5us actual 5587ns [ 51.565715] Expected delay 5us actual 5657ns [ 51.861171] Expected delay 5us actual 5587ns [ 52.164704] Expected delay 5us actual 5726ns [ 52.487457] Expected delay 5us actual 5657ns [ 52.789338] Expected delay 5us actual 5726ns [ 57.119680] Expected delay 10us actual 10755ns [ 57.893997] Expected delay 10us actual 10615ns [ 58.261287] Expected delay 10us actual 10755ns [ 58.620505] Expected delay 10us actual 10825ns [ 58.941035] Expected delay 10us actual 10755ns [ 59.320903] Expected delay 10us actual 10615ns [ 61.306311] Expected delay 10us actual 10755ns [ 61.520542] Expected delay 10us actual 10615ns Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> |
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.. | ||
Makefile | ||
checksum_32.S | ||
clear_page_64.S | ||
copy_page_64.S | ||
copy_user_64.S | ||
copy_user_nocache_64.S | ||
csum-copy_64.S | ||
csum-partial_64.c | ||
csum-wrappers_64.c | ||
delay.c | ||
getuser.S | ||
io_64.c | ||
iomap_copy_64.S | ||
memcpy_32.c | ||
memcpy_64.S | ||
memmove_64.c | ||
memset_64.S | ||
mmx_32.c | ||
msr.c | ||
putuser.S | ||
rwlock_64.S | ||
semaphore_32.S | ||
string_32.c | ||
strstr_32.c | ||
thunk_32.S | ||
thunk_64.S | ||
usercopy_32.c | ||
usercopy_64.c |