Linux smaps rollup

[giampaolo]

Summary

• OS: Linux
• Bug fix: no
• Type: performance
• Fixes: [Linux] Performance optimization for Process.memory_full_info() #2107

Description

Process.memory_full_info() (reporting proecss USS/PSS/Swap memory) now reads /proc/pid/smaps_rollup instead of /proc/pids/smaps which makes it 5 times faster.

Without patch:

~/svn/psutil {linux-smaps-rollup}$ python3 -m timeit -s "import psutil; p = psutil.Process()" "p.memory_full_info()"
500 loops, best of 5: 518 usec per loop

With patch (5 times faster):

~/svn/psutil {linux-smaps-rollup}$ python3 -m timeit -s "import psutil; p = psutil.Process()" "p.memory_full_info()"
2000 loops, best of 5: 111 usec per loop

---

make test-memleaks suite, who heavily rely on Process.memory_full_info(), also received a nice speedup:

Before patch:

$ make test-memleaks
----------------------------------------------------------------------
Ran 99 tests in 1.646s

OK (skipped=9)
SUCCESS

After patch:

$ make test-memleaks
----------------------------------------------------------------------
Ran 99 tests in 1.195s

OK (skipped=9)
SUCCESS