Re: [67/90] intel idle: Make idle driver more robust
From: Michael Tokarev <hidden>
Date: 2012-01-26 15:47:20
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26.01.2012 18:45, Kirill A. Shutemov wrote:
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From: Thomas Renninger<redacted> commit 5c2a9f06a9cd7194f884cdc88144866235dec07d upstream. kvm -cpu host passes the original cpuid info to the guest. Latest kvm version seem to return true for mwait_leaf cpuid function on recent Intel CPUs. But it does not return mwait C-states (mwait_substates), instead zero is returned.
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drivers/idle/intel_idle.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)--- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c@@ -321,7 +321,8 @@ static int intel_idle_probe(void) cpuid(CPUID_MWAIT_LEAF,&eax,&ebx,&ecx,&mwait_substates); if (!(ecx& CPUID5_ECX_EXTENSIONS_SUPPORTED) || - !(ecx& CPUID5_ECX_INTERRUPT_BREAK)) + !(ecx& CPUID5_ECX_INTERRUPT_BREAK) || + !mwait_substates) return -ENODEV;It breaks build for me.
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CC drivers/idle/intel_idle.o /home/space/kas/git/public/linux-3.0-mid/drivers/idle/intel_idle.c: In function ‘intel_idle_probe’: /home/space/kas/git/public/linux-3.0-mid/drivers/idle/intel_idle.c:508:7: error: ‘mwait_substates’ undeclared (first use in this function) /home/space/kas/git/public/linux-3.0-mid/drivers/idle/intel_idle.c:508:7: note: each undeclared identifier is reported only once for each function it appears in make[3]: *** [drivers/idle/intel_idle.o] Error 1 Variable 'substates' hasn't renamed to 'mwait_substates' in 3.0. See c423628 intel_idle: delete substates DEBUG modparam
I wonder why in my 3.0.18 this variable is properly defined in the same file, in line 77: ... 74 /* intel_idle.max_cstate=0 disables driver */ 75 static int max_cstate = MWAIT_MAX_NUM_CSTATES - 1; 76 77 static unsigned int mwait_substates; 78 79 #define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF ...
quoted hunk ↗ jump to hunk
Signed-off-by: Kirill A. Shutemov<redacted> --- drivers/idle/intel_idle.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 15d72ca..a1aecc3 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c@@ -505,7 +505,7 @@ static int intel_idle_probe(void) if (!(ecx& CPUID5_ECX_EXTENSIONS_SUPPORTED) || !(ecx& CPUID5_ECX_INTERRUPT_BREAK) || - !mwait_substates) + !substates)
With this patch my build of 3.0.18 fails with "substates undeclared" message...
if (substates == 0) /* can over-ride via modparam */
And I don't have this context line in my version. It is 3.0 from kernel.org patched by patch-3.0.18.xz Thanks, /mjt