From: Jon Turney <jon.turney@dronecode.org.uk>
To: Mark Geisert <mark@maxrnd.com>,
Cygwin Patches <cygwin-patches@cygwin.com>
Subject: Re: load average calculation failing
Date: Sun, 8 May 2022 11:27:27 +0100 [thread overview]
Message-ID: <223aa826-7bf9-281a-aed8-e16349de5b96@dronecode.org.uk> (raw)
In-Reply-To: <3a3edd10-2617-0919-4eb0-7ca965b48963@maxrnd.com>
On 08/05/2022 08:01, Mark Geisert wrote:
> Mark Geisert wrote (on the main Cygwin mailing list):
>> I've recently noticed that the 'xload' I routinely run shows zero load
>> even with compute-bound processes running. This is on both Cygwin
>> pre-3.4.0 as well as 3.3.4. A test program, shown below, indicates
>> that getloadavg() is returning with 0 status, i.e. not an error but no
>> elems
>> of the passed-in array updated.
>>
>> Stepping with gdb through the test program seems weird within the
>> loadavginfo::load_init method. Single-stepping at line loadavg.cc:68
>> goes to strace.h:52 and then to _sigbe ?!
>>
>> I had recently updated both Cygwin and Windows 10 to latest at the
>> same time so I cannot say when the failure started. Last day or two
>> at most.
>>
[...]
>
> I've debugged a bit further.. Within Cygwin's loadavg.cc:load_init(),
> the PdhOpenQueryW() call returns successfully. The subsequent
> PdhAddEnglishCounterW() call is unsuccessful. It returns status
> 0x800007D0 == PDH_CSTATUS_NO_MACHINE. The code (at line 68 mentioned
> above) calls debug_printf() to conditionally display the error, which is
> what leads to the strace.h and _sigbe; that's fine.
>
> The weird PDH_CSTATUS_NO_MACHINE is the problem. I'll try running the
> example from an elevated shell. Or rebooting the machine. After that
> it's consulting some oracle TBD. :-(
>
Thanks for looking into this.
You can find the user space version of this code I initially wrote at
https://github.com/jon-turney/windows-loadavg, which might save you some
time.
I can't reproduce this on W10 21H1, so I think this must be due to some
change in later Windows...
parent reply other threads:[~2022-05-08 10:27 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <3a3edd10-2617-0919-4eb0-7ca965b48963@maxrnd.com>]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=223aa826-7bf9-281a-aed8-e16349de5b96@dronecode.org.uk \
--to=jon.turney@dronecode.org.uk \
--cc=cygwin-patches@cygwin.com \
--cc=mark@maxrnd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).