9front - general discussion about 9front
 help / color / mirror / Atom feed
From: "Sigrid Solveig Haflínudóttir" <sigrid@ftrv.se>
To: 9front@9front.org
Subject: Re: [9front] Speeding up snoopy(8)
Date: Thu, 20 Oct 2022 18:03:47 +0200	[thread overview]
Message-ID: <26B1535D9EE1F3549FAB661259CC3845@ftrv.se> (raw)
In-Reply-To: <85db2d6b-e60a-4236-9a2c-5b0b77ef99f6@app.fastmail.com>

Quoth David Arroyo <droyo@aqwari.net>:
> I will experiment with putting the pwrite in a separate thread, and
> look for small performance improvements in the other functions. I
> am not sure why nsec() time is so high, but I think that's a function
> that could perform very differently on real vs virtual hardware, so
> I'm hesitant to try to improve it until I get 9front running on a
> real machine.

nsec() is a function that results in a syscall.  It is also affected
by time adjustments, to my knowledge.  At some point I replaced nsec()
call with a (somewhat dirty) nanosec() in vmx, see
/sys/src/cmd/vmx/nanosec.c

It would be nice to have a way to get monotonic timestamps in userspace
without having to go into the kernel. For now, you can try nanosec and
see if anything changes.


  reply	other threads:[~2022-10-20 16:05 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-18  4:57 droyo
2022-10-20 15:55 ` David Arroyo
2022-10-20 16:03   ` Sigrid Solveig Haflínudóttir [this message]
2022-10-21 15:38     ` David Arroyo
2022-10-21 16:04       ` ori
2022-10-21 16:54         ` David Arroyo
2022-10-21 17:10           ` ori
2022-10-21 17:40       ` Lyndon Nerenberg (VE7TFX/VE6BBM)
2022-10-21 18:52         ` ori
2022-10-21 19:23           ` ori

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=26B1535D9EE1F3549FAB661259CC3845@ftrv.se \
    --to=sigrid@ftrv.se \
    --cc=9front@9front.org \
    /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 NNTP newsgroup(s).