All of lore.kernel.org
 help / color / mirror / Atom feed
From: Stan Sieler <sieler@allegro.com>
To: alan@lxorguk.ukuu.org.uk (Alan Cox)
Cc: matthew@wil.cx (Matthew Wilcox), jes@linuxcare.com (Jes Sorensen),
	alan@linuxcare.com.au (Alan Modra),
	jsm@udlkern.fc.hp.com (John Marvin),
	parisc-linux@thepuffingroup.com
Subject: Re: [parisc-linux] ldcw in __pthread_acquire
Date: Sun, 17 Dec 2000 16:29:50 -0800 (PST)	[thread overview]
Message-ID: <200012180029.QAA03444@opus.allegro.com> (raw)
In-Reply-To: <E147TiI-0003X1-00@the-village.bc.nu> from "Alan Cox" at Dec 17, 2000 02:38:10 AM

Re:

> There are good reasons for doing buzzlocks in user space

Not really...they all vanish when you look with the microscope of
experience.  Trust me.  I've been doing this stuff (multi-processor,
semaphores, locks, etc.) for 30 years.  

And, Lamont agrees, apparently :)

(Thanks, Lamont, and hi!)

The apparent advantages are *strictly* short term.  A single mistake
using a buzz lock from user code in a single process on a single computer
can cost more time than all properly implemented buzz locks ever save.

The "it's faster" argument is the same kind of argument as "not indenting my 
code makes it faster to write, because I don't have to waste the 
time pressing that space bar or tab key"....and precisely as bad an argument :)

Operating system functions, strangely enough, deserved to be implemented
in the *operating system*!  Gaining exclusive access to a data structure
is such a function.

-- 
Stan Sieler                                           sieler@allegro.com
www.allegro.com/sieler/wanted/index.html                  www.sieler.com        

  parent reply	other threads:[~2000-12-18  0:28 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2000-12-15 10:12 [parisc-linux] ldcw in __pthread_acquire John Marvin
2000-12-15 11:37 ` Alan Modra
2000-12-15 16:37   ` Matthew Wilcox
2000-12-15 17:32     ` Jes Sorensen
2000-12-16 19:29       ` Matthew Wilcox
2000-12-16 21:58         ` Jes Sorensen
2000-12-17  4:31           ` Alan Modra
2000-12-17  1:22         ` Stan Sieler
2000-12-17  2:38           ` Alan Cox
2000-12-17  4:18             ` LaMont Jones
2000-12-18  0:29             ` Stan Sieler [this message]
2000-12-18  0:36               ` Alan Cox
2000-12-18  0:48                 ` Stan Sieler
2000-12-18  0:59                   ` Alan Cox
2000-12-18  4:43                     ` LaMont Jones
2000-12-18 11:53                       ` Alan Cox
2000-12-18 12:27                         ` Philippe Benard
2000-12-18 14:40                           ` LaMont Jones
2000-12-18 19:44                             ` Stan Sieler
2000-12-18 19:54                               ` Alan Cox
2000-12-18 20:15                                 ` Stan Sieler
2000-12-18 20:44                                 ` LaMont Jones
2000-12-18 21:56                                   ` Alan Cox
2000-12-18 22:26                               ` LaMont Jones
2000-12-18  7:10                 ` Philippe Benard
2000-12-18 12:06                   ` Alan Cox
2000-12-18 14:49                     ` LaMont Jones
2000-12-18 15:59                       ` Matthew Wilcox
  -- strict thread matches above, loose matches on Subject: below --
2000-12-15 10:26 John Marvin

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=200012180029.QAA03444@opus.allegro.com \
    --to=sieler@allegro.com \
    --cc=alan@linuxcare.com.au \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=jes@linuxcare.com \
    --cc=jsm@udlkern.fc.hp.com \
    --cc=matthew@wil.cx \
    --cc=parisc-linux@thepuffingroup.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.