Messages in this thread | | | Subject | Re: [PATCH v3 00/20] Speculative page faults | From | Laurent Dufour <> | Date | Thu, 28 Sep 2017 14:29:02 +0200 |
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Hi Andrew,
On 26/09/2017 01:34, Andrew Morton wrote: > On Mon, 25 Sep 2017 09:27:43 -0700 Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote: > >> On Mon, Sep 18, 2017 at 12:15 AM, Laurent Dufour >> <ldufour@linux.vnet.ibm.com> wrote: >>> Despite the unprovable lockdep warning raised by Sergey, I didn't get any >>> feedback on this series. >>> >>> Is there a chance to get it moved upstream ? >> >> what is the status ? >> We're eagerly looking forward for this set to land, >> since we have several use cases for tracing that >> will build on top of this set as discussed at Plumbers. > > There has been sadly little review and testing so far :( > > I'll be taking a close look at it all over the next couple of weeks. > > One terribly important thing (especially for a patchset this large and > intrusive) is the rationale for merging it: the justification, usually > in the form of end-user benefit. > > Laurent's [0/n] provides some nice-looking performance benefits for > workloads which are chosen to show performance benefits(!) but, alas, > no quantitative testing results for workloads which we may suspect will > be harmed by the changes(?). Even things as simple as impact upon > single-threaded pagefault-intensive workloads and its effect upon > CONFIG_SMP=n .text size?
I forgot to mention in my previous email the impact on the .text section.
Here are the metrics I got :
.text size UP SMP Delta 4.13-mmotm 8444201 8964137 6.16% '' +spf 8452041 8971929 6.15% Delta 0.09% 0.09%
No major impact as you could see.
Thanks, Laurent
> If you have additional usecases then please, spell them out for us in > full detail so we can better understand the benefits which this > patchset provides. >
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