Messages in this thread Patch in this message | | | From | Alexander Pantyukhin <> | Date | Tue, 10 Jan 2023 00:44:20 +0400 | Subject | Re: [PATCH] tools:perf:scripts:python:mem-phys-addr fix performance |
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Hi! There are some things which I would like to discuss there.
1) I found that if there is for example the following system_ram: system_ram = [int('00000000', 16) , int('0000ffff', 16)]
and the func
def is_system_ram(phys_addr): #/proc/iomem is sorted position = bisect.bisect(system_ram, phys_addr) if position % 2 == 0: return False return True
The value: is_system_ram(int('0000ffff', 16)) is False. It seems to be a mistake. This value is the end of the range and it should be a True. (There is another check on the 88 line: if int(m[0], 16) <= phys_addr <= int(m[1], 16) where both ranges are included in the check.)
2) The script reads the whole file when parse_iomem() and uses this information for pmem and system_ram. What if to store whole info about addresses for all memory types? In This case it's possible to store the data structure like the following example:
/proc/iomem 00000000-0000ffff : reserved 00010000-0009f3ff : System RAM
Result: [(00000000, 'reserved'), (0000ffff, 'reserved'), (00010000, 'System RAM'), (0009f3ff, 'System RAM')....]
This case the searching would be O(log(n)) for all types not just for "System RAM" and "Persistent Memory".
But the behavior of the script would be changed: the current version re-read the file and scan the fresh data when neither "System RAM" nor "Persistent Memory". But the suggested fix requires to call parse_iomem() when fresh data is required.
If these changes are approved, I would like to fix it.
Best, Alex.
пн, 9 янв. 2023 г. в 13:33, Alexander Pantyukhin <apantykhin@gmail.com>: > > Avoid double strip() calls for getting memory type. > > Signed-off-by: Alexander Pantyukhin <apantykhin@gmail.com> > --- > tools/perf/scripts/python/mem-phys-addr.py | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/tools/perf/scripts/python/mem-phys-addr.py b/tools/perf/scripts/python/mem-phys-addr.py > index 1f332e72b9b0..f267d8382eda 100644 > --- a/tools/perf/scripts/python/mem-phys-addr.py > +++ b/tools/perf/scripts/python/mem-phys-addr.py > @@ -8,7 +8,6 @@ from __future__ import print_function > > import os > import sys > -import struct > import re > import bisect > import collections > @@ -30,12 +29,14 @@ event_name = None > def parse_iomem(): > global f > f = open('/proc/iomem', 'r') > - for i, j in enumerate(f): > + for _, j in enumerate(f): > m = re.split('-|:',j,2) > - if m[2].strip() == 'System RAM': > + memory_type = m[2].strip() > + > + if memory_type == 'System RAM': > system_ram.append(int(m[0], 16)) > system_ram.append(int(m[1], 16)) > - if m[2].strip() == 'Persistent Memory': > + elif memory_type == 'Persistent Memory': > pmem.append(int(m[0], 16)) > pmem.append(int(m[1], 16)) > > @@ -75,6 +76,7 @@ def is_persistent_mem(phys_addr): > def find_memory_type(phys_addr): > if phys_addr == 0: > return "N/A" > + > if is_system_ram(phys_addr): > return "System RAM" > > -- > 2.25.1 >
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