From: David Edelsohn <dje@watson.ibm.com>
To: Geoff Keating <geoffk@cygnus.com>
Cc: drow@false.org, linuxppc-dev@lists.linuxppc.org,
libc-alpha@sourceware.cygnus.com
Subject: Re: DB_THREAD support in Berkeley DB/glibc
Date: Tue, 28 Dec 1999 19:21:36 -0500 [thread overview]
Message-ID: <199912290021.TAA23598@mal-ach.watson.ibm.com> (raw)
In-Reply-To: Message from Geoff Keating <geoffk@cygnus.com> of "Tue, 28 Dec 1999 15:52:47 PST." <199912282352.PAA11865@localhost.cygnus.com>
>>>>> Geoff Keating writes:
Geoff> We don't need 'isync', 'sync' will do just fine, and is faster. We
Geoff> are only concerned here with memory coherency. In fact, 'isync' does
Geoff> not imply 'sync' in a multiprocessor implementation; 'sync' does an
Geoff> extra broadcast on the bus. The PowerPC User's Manual says
Geoff> The sync instruction can be used to ensure that the result of all
Geoff> stores into a data structure, performed in a "critical section" of a
Geoff> program, are seen by other processors before the data structure is
Geoff> seen as unlocked.
Geoff> We probably want 'sync' before and after, although it's probable the
Geoff> 'after' is unnecessary.
"sync" is not faster; sync is a full context synchronization
instruction. As I had mentioned to David, the necessity of a sync *after*
the store depends on the semantics of this programming model. Maybe in
this context one should sync before acquiring the lock and then sync after
releasing the lock.
David
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~1999-12-29 0:21 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-12-27 3:04 DB_THREAD support in Berkeley DB/glibc Troy Benjegerdes
1999-12-28 7:59 ` Daniel Jacobowitz
1999-12-28 17:53 ` Joel Klecker
1999-12-28 19:02 ` David Edelsohn
1999-12-28 21:22 ` BenH
1999-12-28 22:05 ` Daniel Jacobowitz
1999-12-28 22:28 ` David Edelsohn
1999-12-28 23:21 ` Tony Mantler
1999-12-29 0:15 ` David Edelsohn
1999-12-29 0:54 ` Geoff Keating
1999-12-29 1:01 ` David Edelsohn
1999-12-28 23:52 ` Geoff Keating
1999-12-29 0:21 ` David Edelsohn [this message]
-- strict thread matches above, loose matches on Subject: below --
1999-05-10 23:59 imac of booting Ben Martz
1999-05-11 8:36 ` Joel Klecker
1999-05-11 15:22 ` David Edelsohn
1999-05-11 16:47 ` Geert Uytterhoeven
1999-05-11 17:44 ` Anyone playing with Darwin 0.2 binary yet? Kevin B. Hendricks
1999-05-11 18:47 ` Nathan Ingersoll
1999-05-11 21:00 ` Roger Ivie
1999-05-11 22:15 ` David A. Gatwood
[not found] ` <v04011701b35e71c158ed@[199.174.98.46]>
1999-05-12 14:50 ` New PPC/Mac features of 2.2.8? Jason Haas
1999-05-12 18:21 ` Matt Porter
1999-05-12 19:41 ` Tom Rini
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=199912290021.TAA23598@mal-ach.watson.ibm.com \
--to=dje@watson.ibm.com \
--cc=drow@false.org \
--cc=geoffk@cygnus.com \
--cc=libc-alpha@sourceware.cygnus.com \
--cc=linuxppc-dev@lists.linuxppc.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).