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authorVitaly Kuznetsov <vkuznets@redhat.com>2017-10-06 17:48:54 +0200
committerIngo Molnar <mingo@kernel.org>2017-10-10 12:53:00 +0200
commita3b7424392924e778b608e30ee321f7b10cc94b8 (patch)
tree91d209fb697122bffcffb9225a1b97a5b6036acf /arch/x86/include/asm
parentd4a2d031dd42f9594107d317e2a9a0c6d73ad46b (diff)
x86/hyperv: Clear vCPU banks between calls to avoid flushing unneeded vCPUs
hv_flush_pcpu_ex structures are not cleared between calls for performance reasons (they're variable size up to PAGE_SIZE each) but we must clear hv_vp_set.bank_contents part of it to avoid flushing unneeded vCPUs. The rest of the structure is formed correctly. To do the clearing in an efficient way stash the maximum possible vCPU number (this may differ from Linux CPU id). Reported-by: Jork Loeser <Jork.Loeser@microsoft.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20171006154854.18092-1-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm')
-rw-r--r--arch/x86/include/asm/mshyperv.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 738503e1f80c..530f448fddaf 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -289,6 +289,7 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
* to this information.
*/
extern u32 *hv_vp_index;
+extern u32 hv_max_vp_index;
/**
* hv_cpu_number_to_vp_number() - Map CPU to VP.

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