Messages in this thread | | | Subject | Re: [PATCH] arm64: KVM: Save two instructions in __guest_enter() | From | Shanker Donthineni <> | Date | Mon, 29 Aug 2016 10:22:06 -0500 |
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Hi Christoffer,
This is change may not provide the measurable performance improvement, but still we can save a few cpu cycles on vCPU context switch and also improves the code readability.
On 08/25/2016 08:31 AM, Christoffer Dall wrote: > Hi Shanker, > > On Tue, Aug 09, 2016 at 08:15:36PM -0500, Shanker Donthineni wrote: >> We are doing an unnecessary stack push/pop operation when restoring >> the guest registers x0-x18 in __guest_enter(). This patch saves the >> two instructions by using x18 as a base register. No need to store >> the vcpu context pointer in stack because it is redundant and not >> being used anywhere, the same information is available in tpidr_el2. > Does this have any measureable benefit? > > Thanks, > -Christoffer
-- Shanker Donthineni Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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