Re: [PATCH bpf-next v2 0/5] execmem_alloc for BPF programs

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, 2022-11-07 at 15:39 -0800, Luis Chamberlain wrote:
> On Mon, Nov 07, 2022 at 03:13:59PM -0800, Song Liu wrote:
> > The benchmark used here is identical on our web service, which runs
> > on
> > many many servers, so it represents the workload that we care a
> > lot.
> > Unfortunately, it is not possible to run it out of our data
> > centers.
> 
> I am not asking for that, I am asking for you to pick any similar
> benchark which can run in paralellel which may yield similar results.
> 
> > We can build some artificial workloads and probably get much higher
> > performance improvements. But these workload may not represent real
> > world use cases.
> 
> You can very likely use some existing benchmark.
> 
> The direct map fragmentation stuff doesn't require much effort, as
> was demonstrated by Aaron, you can easily do that or more by
> running all selftests or just the test_bpf. This I buy.
> 
> I'm not buying the iTLB gains as I can't even reproduce them myself
> for
> eBPF JIT, but I tested against iTLB when using eBPF JIT, perhaps you
> mean iTLB gains for other memory intensive applications running in
> tandem?

Song, didn't you find that there wasn't (or in the noise) iTLB gains?
What is this about visible performance drop from iTLB misses?

IIRC there was a test done where progpack mapped things at 4k, but in
2MB chunks, so it would re-use pages like the 2MB mapped version. And
it didn't see much improvement over the 2MB mapped version. Did I
remember that wrong?

> 
> And none of your patches mentions the gains of this effort helping
> with the long term advantage of centralizing the semantics for
> permissions on memory.

Another good point. Although this brings up that this interface
"execmem" does just handle one type of permission.




[Index of Archives]     [Linux Samsung SoC]     [Linux Rockchip SoC]     [Linux Actions SoC]     [Linux for Synopsys ARC Processors]     [Linux NFS]     [Linux NILFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]


  Powered by Linux