group.of.nepali.translators team mailing list archive

[dann frazier <dann.frazier@xxxxxxxxxxxxx>]

** Also affects: lshw (Ubuntu Artful)
   Importance: Undecided
       Status: New

** Also affects: lshw (Ubuntu Xenial)
   Importance: Undecided
       Status: New

** Also affects: lshw (Ubuntu Bionic)
   Importance: Undecided
     Assignee: Ike Panhc (ikepanhc)
       Status: In Progress

** Description changed:

- lshw on AArch64 hardware is painfully slow.
- This affects both lshw in current Ubuntu releases and vanilla upstream.
- 
- For a 48 core node, cpuinfo parsing added up to 30 seconds (8 lines
- per core in /proc/cpuinfo add up to 384 lines to parse).
- 
- For a 96 core node, parsing took up to 5 minutes (!).
- 
- I think the problem was introduced by [1], and can be summarized as:
- - CPU capabilities should be added only to the current CPU core,
-   and NOT to all previous CPU cores parsed.
- 
- My suggestion is dropping the loop in [1], thus calling the <addHint>
- and <describeCapability> only for currentcpu.
- 
- I put together a small patch (basically removing the for loop in question)
- at [2] (or see attachement), which should be applied on top of version
- "02.16-2ubuntu1.3" from Ubuntu Trusty 14.04.
- 
- After applying the patch at [2], parsing for the above system (48 cores)
- takes less than 1 second (instead of 30s), with the exact same results ...
- 
- [1]
- https://github.com/lyonel/lshw/commit/beb89de5a3c10449fe73f1c77b2486d868e5bc9a
- #diff-f4010714738fa4cdd5999499579da2b3R217
- 
- [2] http://paste.ubuntu.com/16456620/
- 
- # lsb_release -rd
- Description:    Ubuntu 14.04.4 LTS
- Release:        14.04
- 
- BR,
- Alex
- 
  [Impact]
  lshw takes too long time on parsing /proc/cpuinfo on aarch64 system
  It takes minutes on 96cores and almost 10min on 224cores system.
  
  [Test Case]
  `time sudo lshw` and it shall be less then 15sec
  
  [Regression Potential]
  This patch only modifies codes for aarch64. Lowest regression rick on other arch and has been tested on aarch64
  
  [Other Info]
  Patch has been merged into upstream branch.
  https://github.com/lyonel/lshw/commit/20cda77239e8604e798b87a0441e694edb0214d1

-- 
You received this bug notification because you are a member of नेपाली
भाषा समायोजकहरुको समूह, which is subscribed to Xenial.
Matching subscriptions: Ubuntu 16.04 Bugs
https://bugs.launchpad.net/bugs/1582181

Title:
  AArch64: slow cpuinfo due to redundant loop

Status in lshw package in Ubuntu:
  In Progress
Status in lshw source package in Xenial:
  New
Status in lshw source package in Artful:
  New
Status in lshw source package in Bionic:
  In Progress

Bug description:
  [Impact]
  lshw takes too long time on parsing /proc/cpuinfo on aarch64 system
  It takes minutes on 96cores and almost 10min on 224cores system.

  [Test Case]
  `time sudo lshw` and it shall be less then 15sec

  [Regression Potential]
  This patch only modifies codes for aarch64. Lowest regression rick on other arch and has been tested on aarch64

  [Other Info]
  Patch has been merged into upstream branch.
  https://github.com/lyonel/lshw/commit/20cda77239e8604e798b87a0441e694edb0214d1

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/lshw/+bug/1582181/+subscriptions