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| author |   Anton Blanchard <anton@samba.org> | 2015-10-29 11:44:08 +1100 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2015-12-02 19:34:26 +1100 |
| commit | c208505900b232ecdc81dee54cb3a032e75d88d6 (patch) | |
| tree | e63fe696c5a8404bc4257204502f0d6f9ed3ccaf /arch/powerpc/kvm/book3s_pr.c | |
| parent | powerpc: Remove fp_enable() and vec_enable(), use msr_check_and_{set, clear}() (diff) | |
| download | linux-dev-c208505900b232ecdc81dee54cb3a032e75d88d6.tar.xz linux-dev-c208505900b232ecdc81dee54cb3a032e75d88d6.zip | |
powerpc: create giveup_all()
Create a single function that gives everything up (FP, VMX, VSX, SPE).
Doing this all at once means we only do one MSR write.
A context switch microbenchmark using yield():
http://ozlabs.org/~anton/junkcode/context_switch2.c
./context_switch2 --test=yield --fp --altivec --vector 0 0
shows an improvement of 3% on POWER8.
Signed-off-by: Anton Blanchard <anton@samba.org>
[mpe: giveup_all() needs to be EXPORT_SYMBOL'ed]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/kvm/book3s_pr.c | 17 |
1 files changed, 2 insertions, 15 deletions
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 49f5dad1bd45..a78e0e6bd932 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1490,21 +1490,8 @@ static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) goto out; /* interrupts now hard-disabled */ - /* Save FPU state in thread_struct */ - if (current->thread.regs->msr & MSR_FP) - giveup_fpu(current); - -#ifdef CONFIG_ALTIVEC - /* Save Altivec state in thread_struct */ - if (current->thread.regs->msr & MSR_VEC) - giveup_altivec(current); -#endif - -#ifdef CONFIG_VSX - /* Save VSX state in thread_struct */ - if (current->thread.regs->msr & MSR_VSX) - __giveup_vsx(current); -#endif + /* Save FPU, Altivec and VSX state */ + giveup_all(current); /* Preload FPU if it's enabled */ if (kvmppc_get_msr(vcpu) & MSR_FP) |