From: "Rajan Ravindran" <rajancr@us.ibm.com>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: linux-kernel@vger.kernel.org, lse-tech@lists.sourceforge.net
Subject: Re: Fwd: [Lse-tech] get_pid() performance fix
Date: Tue, 5 Mar 2002 11:43:24 -0500 [thread overview]
Message-ID: <OF810580E6.8672B341-ON85256B73.005AF9B8@pok.ibm.com> (raw)
Yes, pid's are guaranteed to be unique.
Here the problem we focused is the time taken in finding the next
available free pid.
I really don't mean by your task->xxx.
-Rajan
Hubertus Franke <frankeh@watson.ibm.com> writes:
> @@ -153,13 +155,18 @@
> if(last_pid & 0xffff8000)
> last_pid = 300;
> next_safe = PID_MAX;
> + goto repeat;
> }
> - goto repeat;
> + if(unlikely(last_pid == beginpid))
> + goto nomorepids;
> + continue;
It isn't guaranteed that pid is unique.
In the case:
task->pid = 300, task->xxx = 301
pid 301 is free
This get_pid() returns 301.
Regards.
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
_______________________________________________
Lse-tech mailing list
Lse-tech@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/lse-tech
next reply other threads:[~2002-03-05 16:44 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-03-05 16:43 Rajan Ravindran [this message]
2002-03-05 17:57 ` Fwd: [Lse-tech] get_pid() performance fix OGAWA Hirofumi
2002-03-05 19:53 ` Hubertus Franke
2002-03-05 20:10 ` OGAWA Hirofumi
2002-03-05 21:59 ` Hubertus Franke
2002-03-05 22:48 ` OGAWA Hirofumi
2002-03-05 23:40 ` Hubertus Franke
2002-03-14 23:18 ` [PATCH] " Hubertus Franke
2002-03-15 14:57 ` OGAWA Hirofumi
2002-03-15 15:16 ` OGAWA Hirofumi
2002-03-15 18:37 ` Hubertus Franke
2002-03-16 5:12 ` OGAWA Hirofumi
2002-03-18 21:44 ` Hubertus Franke
2002-03-22 22:14 ` Hubertus Franke
2002-03-22 22:28 ` Davide Libenzi
2002-03-22 22:26 ` Hubertus Franke
-- strict thread matches above, loose matches on Subject: below --
2002-03-07 22:37 Fwd: [Lse-tech] " Manfred Spraul
2002-03-05 1:57 Hubertus Franke
2002-03-05 16:26 ` OGAWA Hirofumi
2002-03-05 16:43 ` Hubertus Franke
2002-03-07 3:56 ` Rusty Russell
2002-03-07 14:35 ` Hubertus Franke
2002-03-07 14:54 ` Guest section DW
2002-03-07 19:07 ` Hubertus Franke
2002-03-07 19:44 ` Richard B. Johnson
2002-03-07 19:46 ` Guest section DW
2002-03-07 23:14 ` Hubertus Franke
2002-03-07 15:21 ` Dave McCracken
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=OF810580E6.8672B341-ON85256B73.005AF9B8@pok.ibm.com \
--to=rajancr@us.ibm.com \
--cc=hirofumi@mail.parknet.co.jp \
--cc=linux-kernel@vger.kernel.org \
--cc=lse-tech@lists.sourceforge.net \
/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).