Performance Counter Addresses

Robert O'Callahan robert at
Mon Oct 5 02:05:52 UTC 2015

On Mon, Oct 5, 2015 at 2:52 PM, Downing, Evan P <edowning3 at>

> I'm gathering data such as network traffic, plugins installed, files
> downloaded using Firefox, etc.
> I could just use PANDA, but extracting the information could take a long
> time.
> The performance overhead is large.

What's PANDA's recording performance overhead?

It would be faster if I used rr to extract preliminary information to
> determine if the data is worth studying more, and then perform an in-depth
> analysis using PANDA.
> Sort of like zooming in on the problem (using PANDA) once I've discovered
> it (using rr).

For that to work, your best bet is probably to use rr to record a Firefox
session, running the whole thing under QEMU-KVM with PMU enabled. Then
switch the QEMU mode to PANDA, and run rr replay in it. But you would need
to extend QEMU/TCG to support the retired-conditional-branches counter.

lbir ye,ea yer.tnietoehr  rdn rdsme,anea lurpr  edna e hnysnenh hhe uresyf
selthor  stor  edna  siewaoeodm  or v sstvr  esBa  kbvted,t
o l euetiuruewFa  kbn e hnystoivateweh uresyf tulsa rehr  rdm  or rnea
.a war hsrer holsa rodvted,t  nenh hneireseoouot.tniesiewaoeivatewt sstvr
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the rr-dev mailing list