x86: udelay: Use this_cpu_read to avoid address calculation

2011-01-04T05:08:55Z

The code will use a segment prefix instead of doing the lookup and calculation. Signed-off-by: Christoph Lameter Acked-by: "H. Peter Anvin" Signed-off-by: Tejun Heo

x86, delay: tsc based udelay should have rdtsc_barrier

2009-06-25T23:47:40Z

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 Signed-off-by: H. Peter Anvin

x86: integrate delay functions.

2008-07-09T06:52:05Z

delay_32.c, delay_64.c are now equal, and are integrated into delay.c. Signed-off-by: Glauber Costa Signed-off-by: H. Peter Anvin Signed-off-by: Ingo Molnar

kernel.git/arch/x86/lib/delay.c, branch linux-3.1.y

x86: udelay: Use this_cpu_read to avoid address calculation

x86, delay: tsc based udelay should have rdtsc_barrier

x86: integrate delay functions.