Bug#915877: linux-perf-4.18 in Stretch bpo is not linked with libunwind

[Szabolcs Fazekas <szabolcs.fazekas@ahrefs.com>]

package: linux-perf-4.18

version: 4.18.6-1~bpo9+1

Package is not linked with libunwind, which makes perf report very slow when dwarf graph is used.

How to reproduce:

$ sudo perf_4.18 record -F 200 -p 38429 --call-graph dwarf sleep 120

$ time sudo perf report -G --no-inline > /dev/null

real    5m18.259s
user    5m10.644s
sys    0m7.527s

I managed to rebuild linux-perf-4.18 manually with libunwind. Using the exact same set of samples, this is how it performs:

$ time sudo perf_4.18 report -G --no-inline > /dev/null

real    0m0.846s
user    0m0.654s
sys    0m0.190s

I confirmed the followings:

 - linux-perf-4.9 is linked with libunwind and performs properly

 - linux-perf-* packages in sid/experimental are also linked with libunwind

 - linux-perf-* (>4.9) in Stretch backports are not linked with libunwind and they perform poorly

I suggest to rebuild all linux-perf packages in Stretch backports with libunwind linked.

--

Szabolcs Fazekas

Ahrefs