Messages in this thread | | | Date | Mon, 28 Jan 2013 23:07:58 -0200 | From | Marcelo Tosatti <> | Subject | Re: [PATCH v2 06/12] KVM: MMU: introduce a static table to map guest access to spte access |
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On Mon, Jan 28, 2013 at 10:07:15PM -0200, Marcelo Tosatti wrote: > On Fri, Jan 25, 2013 at 10:46:31AM +0800, Xiao Guangrong wrote: > > On 01/25/2013 08:15 AM, Marcelo Tosatti wrote: > > > On Wed, Jan 23, 2013 at 06:07:20PM +0800, Xiao Guangrong wrote: > > >> It makes set_spte more clean and reduces branch prediction > > >> > > >> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> > > >> --- > > >> arch/x86/kvm/mmu.c | 37 ++++++++++++++++++++++++++----------- > > >> 1 files changed, 26 insertions(+), 11 deletions(-) > > > > > > Don't see set_spte as being a performance problem? > > > IMO the current code is quite simple. > > > > Yes, this is not a performance problem. > > > > I just dislike this many continuous "if"-s in the function: > > > > if (xxx) > > xxx > > if (xxx) > > xxx > > .... > > > > Totally, it has 7 "if"-s before this patch. > > > > Okay, if you think this is unnecessary, i will drop this patch. :) > > Yes, please (unless you can show set_spte is a performance problem).
Same thing for spte fast drop: is it a performance problem?
Please try to group changes into smaller, less controversial sets with a clear goal:
- Debated performance improvement. - Cleanups (eg mmu_set_spte argument removal). - Bug fixes. - Performance improvements.
Thanks.
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