lkml.org 
[lkml]   [2015]   [May]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v4 10/29] bpf tools: Collect map definitions from 'maps' section
On Thu, May 28, 2015 at 11:09:50AM +0800, Wangnan (F) wrote:
>
> However this breaks a law in current design that opening phase doesn't
> talk to kernel with sys_bpf() at all. All related staff is done in loading
> phase. This principle ensures that in every systems, no matter it support
> sys_bpf() or not, can read eBPF object without failure.

I see, so you want 'parse elf' and 'create maps + load programs'
to be separate phases?
Fair enough. Then please add a call to release the information
collected from elf after program loading is done.
relocations and other things are not needed at that point.

> Moreover, we are planning to introduce hardware PMU to eBPF in the way like
> maps,
> to give eBPF programs the ability to access hardware PMU counter. I haven't

that's very interesting. Please share more info when you can :)
If I understood it right, you want in-kernel bpf to do aggregation
and filtering of pmu counters ?
And computing a number of cache misses between two kprobe events?
I can see how I can use that to measure not only time
taken by syscall, but number of cache misses occurred due
to syscall. Sounds very useful!



\
 
 \ /
  Last update: 2015-05-28 08:41    [W:1.962 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site