q3k
/
linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
linux/arch/x86/lib
History
Pallipadi, Venkatesh e888d7facd x86, delay: tsc based udelay should have rdtsc_barrier 
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>
 		2009-06-25 16:47:40 -07:00
..
Makefile x86: MSR: add a struct representation of an MSR 2009-06-10 12:18:42 +02:00
checksum_32.S
…
clear_page_64.S
…
copy_page_64.S
…
copy_user_64.S x86: wrong register was used in align macro 2008-07-30 10:10:39 -07:00
copy_user_nocache_64.S x86: wrong register was used in align macro 2008-07-30 10:10:39 -07:00
csum-copy_64.S
…
csum-partial_64.c x86: fix csum_partial() export 2008-05-13 19:38:47 +02:00
csum-wrappers_64.c x86: clean up csum-wrappers_64.c some more 2008-02-19 16:18:32 +01:00
delay.c x86, delay: tsc based udelay should have rdtsc_barrier 2009-06-25 16:47:40 -07:00
getuser.S x86: use _types.h headers in asm where available 2009-02-13 11:35:01 -08:00
io_64.c x86: coding style fixes in arch/x86/lib/io_64.c 2008-02-19 16:18:32 +01:00
iomap_copy_64.S
…
memcpy_32.c x86: coding style fixes to arch/x86/lib/memcpy_32.c 2008-04-17 17:40:49 +02:00
memcpy_64.S x86: memcpy, clean up 2009-03-12 12:21:17 +01:00
memmove_64.c x86: coding style fixes to arch/x86/lib/memmove_64.c 2008-04-17 17:40:48 +02:00
memset_64.S
…
mmx_32.c x86: clean up mmx_32.c 2008-04-17 17:40:47 +02:00
msr.c x86: MSR: add methods for writing of an MSR on several CPUs 2009-06-10 12:18:43 +02:00
putuser.S x86: merge putuser asm functions. 2008-07-09 09:14:13 +02:00
rwlock_64.S x86: rename .i assembler includes to .h 2007-10-17 20:16:29 +02:00
semaphore_32.S Generic semaphore implementation 2008-04-17 10:42:34 -04:00
string_32.c x86: coding style fixes to arch/x86/lib/string_32.c 2008-08-15 16:53:25 +02:00
strstr_32.c x86: coding style fixes to arch/x86/lib/strstr_32.c 2008-08-15 16:53:24 +02:00
thunk_32.S ftrace: trace irq disabled critical timings 2008-05-23 20:32:46 +02:00
thunk_64.S ftrace: trace irq disabled critical timings 2008-05-23 20:32:46 +02:00
usercopy_32.c x86: use early clobbers in usercopy*.c 2009-01-21 09:43:17 +01:00
usercopy_64.c x86, 64-bit: Clean up user address masking 2009-06-20 15:40:00 -07:00