From: "fche at redhat dot com" <sourceware-bugzilla@sourceware.org>
To: systemtap@sources.redhat.com
Subject: [Bug translator/2056] avoid locking within foreach iteration for maps & pmaps
Date: Thu, 05 Jan 2006 22:08:00 -0000 [thread overview]
Message-ID: <20060105220845.23094.qmail@sourceware.org> (raw)
In-Reply-To: <20051214214948.2056.hunt@redhat.com>
------- Additional Comments From fche at redhat dot com 2006-01-05 22:08 -------
(In reply to comment #4)
> Maybe I'm missing something, but the problem is the writelock. Why does the
> generated code take a writelock on the pmap when it is reading stats? [...]
We would hold an exclusive ("write") lock around a pmap iteration in order to
prevent concurrent updates to it. This is exactly analogous to taking a shared
("read") lock around a scalar foreach.
With the changes of bug #2057, there is now no translator-emitted locking around
accumulation, which may now expose us to this problem. The translator should
probably do what I originally intended: emit a shared ("read") lock around
accumulation, and rely in no way on spinlocks in the runtime.
--
http://sourceware.org/bugzilla/show_bug.cgi?id=2056
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.
next prev parent reply other threads:[~2006-01-05 22:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-14 23:32 [Bug translator/2056] New: Cannot iterate pmaps hunt at redhat dot com
2005-12-21 20:37 ` [Bug translator/2056] " joshua dot i dot stone at intel dot com
2005-12-21 20:45 ` joshua dot i dot stone at intel dot com
2005-12-22 1:17 ` fche at redhat dot com
2006-01-04 21:00 ` [Bug translator/2056] avoid locking within foreach iteration for maps & pmaps fche at redhat dot com
2006-01-05 6:08 ` hunt at redhat dot com
2006-01-05 22:08 ` fche at redhat dot com [this message]
2006-01-05 22:35 ` hunt at redhat dot com
2006-01-13 3:58 ` joshua dot i dot stone at intel dot 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=20060105220845.23094.qmail@sourceware.org \
--to=sourceware-bugzilla@sourceware.org \
--cc=systemtap@sources.redhat.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).