From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <431F6692-904D-4424-9036-C74FAB969B7C@lsub.org> References: <431F6692-904D-4424-9036-C74FAB969B7C@lsub.org> From: Richard Miller <9fans@hamnavoe.com> Date: Tue, 25 Jul 2017 19:51:24 +0100 Message-ID: To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: multipart/alternative; boundary="001a113e7f84764b68055528d1ab" Subject: Re: [9fans] double lock in proc.c Topicbox-Message-UUID: c08ba2b6-ead9-11e9-9d60-3106f5b1d025 --001a113e7f84764b68055528d1ab Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I'm not convinced that I recall not being convinced ... :) Essentially I changed the order of lock acquire/release so that the canlock() loop in proc.c:/^postnote could be eliminated. Not significant for performance, but it seemed more elegant and I think it also avoided looking at any shared data outside code regions protected by a lock. This was many years ago (when my now-white beard was still merely grey). Not worth going back to reconstruct the arguments, but I'll send Giacomo and Nemo a copy of my proc.c to examine for themselves. On 24 July 2017 at 20:13, Fran. J Ballesteros wrote: > do you remember the proposal? > thanks > > El 24 jul 2017, a las 18:39, Erik Quanstrom > escribi=C3=B3: > > I had a discussion with Richard about this a few years ago. Richard was > no longer convinced of the solution. at the time I agreed with his > reasoning. the comment should be changed. > > - erik > > --001a113e7f84764b68055528d1ab Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I'm not convinced that I recall not being convinced ..= . :)

Essentially I changed the order of lock acquire/release s= o that the canlock() loop in proc.c:/^postnote could be eliminated.=C2=A0 N= ot significant for performance, but it seemed more elegant and I think it a= lso avoided looking at any shared data outside code regions protected by a = lock.

This was many years ago (when my now-w= hite beard was still merely grey).=C2=A0 Not worth going back to reconstruc= t the arguments, but I'll send Giacomo and Nemo a copy of my proc.c to = examine for themselves.

On 24 July 2017 at 20:13, Fran. J Ballesteros <nemo@lsub.org&g= t; wrote:

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