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Groups > linux.kernel > #1164456
| From | Andy Lutomirski <luto@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 07/17] x86/cpu/amd: Use the full 64-bit TSC to detect the 2.6.2 bug |
| Date | 2015-06-13 01:50 +0200 |
| Message-ID | <pAGRZ-44S-45@gated-at.bofh.it> (permalink) |
| References | <pAGRX-44S-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
This code is timing 100k indirect calls, so the added overhead of counting the number of cycles elapsed as a 64-bit number should be insignificant. Drop the optimization of using a 32-bit count. Signed-off-by: Andy Lutomirski <luto@kernel.org> --- arch/x86/kernel/cpu/amd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 5bd3a99dc20b..c5ceec532799 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -107,7 +107,7 @@ static void init_amd_k6(struct cpuinfo_x86 *c) const int K6_BUG_LOOP = 1000000; int n; void (*f_vide)(void); - unsigned long d, d2; + u64 d, d2; printk(KERN_INFO "AMD K6 stepping B detected - "); @@ -118,10 +118,10 @@ static void init_amd_k6(struct cpuinfo_x86 *c) n = K6_BUG_LOOP; f_vide = vide; - rdtscl(d); + d = native_read_tsc(); while (n--) f_vide(); - rdtscl(d2); + d2 = native_read_tsc(); d = d2-d; if (d > 20*K6_BUG_LOOP) -- 2.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH 00/17] x86/tsc: Clean up rdtsc helpers Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 13/17] x86/tsc: Rename native_read_tsc() to rdtsc_unordered() Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 16/17] x86/tsc: Use rdtsc_ordered() in check_tsc_warp() and drop extra barriers Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 04/17] x86/tsc: Remove the rdtscp and rdtscpll macros Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 02/17] x86/msr/kvm: Remove vget_cycles() Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 14/17] x86/tsc: Move rdtsc_barrier() and rename it to barrier_before_rdtsc() Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 15/17] x86: Add rdtsc_ordered() and use it in trivial call sites Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 10/17] input/joystick/analog: Switch from rdtscl() to native_read_tsc() Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 07/17] x86/cpu/amd: Use the full 64-bit TSC to detect the 2.6.2 bug Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 11/17] drivers/input/gameport: Replace rdtscl() with native_read_tsc() Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 17/17] x86/tsc: In read_tsc, use rdtsc_ordered() instead of get_cycles() Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 09/17] staging/lirc_serial: Remove TSC-based timing Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 16/17] x86/tsc: Use rdtsc_unordered() in check_tsc_warp() Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 12/17] x86/tsc: Remove rdtscl() Andy Lutomirski <luto@kernel.org> - 2015-06-13 01:50 +0200 [PATCH 03/17] x86/tsc: Replace rdtscll with native_read_tsc Andy Lutomirski <luto@kernel.org> - 2015-06-13 02:00 +0200 [PATCH 01/17] x86/tsc: Inline native_read_tsc and remove __native_read_tsc Andy Lutomirski <luto@kernel.org> - 2015-06-13 02:00 +0200 [PATCH 08/17] baycom_epp: Replace rdtscl() with native_read_tsc() Andy Lutomirski <luto@kernel.org> - 2015-06-13 02:00 +0200 [PATCH 03/17] x86/tsc/paravirt: Remove the read_tsc and read_tscp paravirt hooks Andy Lutomirski <luto@kernel.org> - 2015-06-13 02:00 +0200 [PATCH 05/17] x86/tsc: Remove the rdtscp and rdtscpll macros Andy Lutomirski <luto@kernel.org> - 2015-06-13 02:00 +0200 [PATCH 06/17] x86/tsc: Use the full 64-bit tsc in tsc_delay Andy Lutomirski <luto@kernel.org> - 2015-06-13 02:00 +0200 [PATCH 04/17] x86/tsc: Replace rdtscll with native_read_tsc Andy Lutomirski <luto@kernel.org> - 2015-06-13 02:00 +0200 [PATCH 05/17] x86/tsc/paravirt: Remove the read_tsc and read_tscp paravirt hooks Andy Lutomirski <luto@kernel.org> - 2015-06-13 02:00 +0200
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