Commit Graph

8 Commits

Author SHA1 Message Date
Pallipadi, Venkatesh e736ad548d x86: add clflush before monitor for Intel 7400 series
For Intel 7400 series CPUs, the recommendation is to use a clflush on the
monitored address just before monitor and mwait pair [1].

This clflush makes sure that there are no false wakeups from mwait when the
monitored address was recently written to.

[1] "MONITOR/MWAIT Recommendations for Intel Xeon Processor 7400 series"
    section in specification update document of 7400 series
    http://download.intel.com/design/xeon/specupdt/32033601.pdf

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09 11:15:15 +01:00
Ingo Molnar d437797406 x86: support always running TSC on Intel CPUs, add cpufeature definition
Impact: add new synthetic-cpuid bit definition

add X86_FEATURE_NONSTOP_TSC to the cpufeature bits - this is in
preparation of Venki's always-running-TSC patch.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 21:01:15 +01:00
Hannes Eder 050dc6944b x86: remove duplicate #define from 'cpufeature.h'
Impact: cleanup

Remove duplicate #define from 'cpufeature.h'.

This also fixes the following sparse warning:

 arch/x86/kernel/cpu/capflags.c:54:3: warning: Initializer entry defined twice
 arch/x86/kernel/cpu/capflags.c:58:3:   also defined here

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23 13:38:50 +01:00
Alok Kataria 49ab56ac6e x86: add X86_FEATURE_HYPERVISOR feature bit
Impact: Number declaration only.

Add X86_FEATURE_HYPERVISOR bit (CPUID level 1, ECX, bit 31).

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-11-01 18:45:37 -07:00
Alok Kataria b2bcc7b299 x86: add a synthetic TSC_RELIABLE feature bit
Impact: None, bit reservation only

Add a synthetic TSC_RELIABLE feature bit which will be used to mark
TSC as reliable so that we could skip all the runtime checks for
TSC stablity, which have false positives in virtual environment.

Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-31 14:44:19 -07:00
Venki Pallipadi 2576c99917 x86: fix AMDC1E and XTOPOLOGY conflict in cpufeature
Impact: fix xsave slowdown regression

Fix two features from conflicting in feature bits.

Fixes this performance regression:

   Subject: cpu2000(both float and int) 13% regression with 2.6.28-rc1
   http://lkml.org/lkml/2008/10/28/36

Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Bisected-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-31 11:01:40 +01:00
H. Peter Anvin 1965aae3c9 x86: Fix ASM_X86__ header guards
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since:

a. the double underscore is ugly and pointless.
b. no leading underscore violates namespace constraints.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:23 -07:00
Al Viro bb8985586b x86, um: ... and asm-x86 move
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:20 -07:00