From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1CRw50-0007N8-Fk for user-mode-linux-devel@lists.sourceforge.net; Wed, 10 Nov 2004 09:16:22 -0800 Received: from smtp001.mail.ukl.yahoo.com ([217.12.11.32]) by sc8-sf-mx1.sourceforge.net with smtp (Exim 4.41) id 1CRw4z-0007ad-Lk for user-mode-linux-devel@lists.sourceforge.net; Wed, 10 Nov 2004 09:16:22 -0800 From: Blaisorblade Subject: Re: [uml-devel] Re: Stop at startup on 2.6 NPTL hosts References: <20041029092641.8558.qmail@web26102.mail.ukl.yahoo.com> <200411092012.05383.blaisorblade_spam@yahoo.it> <34658.80.203.1.124.1100075791.squirrel@80.203.1.124> In-Reply-To: <34658.80.203.1.124.1100075791.squirrel@80.203.1.124> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200411101816.39361.blaisorblade_spam@yahoo.it> Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Wed, 10 Nov 2004 18:16:39 +0100 To: user-mode-linux-devel@lists.sourceforge.net Cc: stian@nixia.no, Bodo Stroesser , Jeff Dike , Roland Kaeser , Nuno Silva , Antoine Martin , Sven =?utf-8?q?K=EF=BF=BDhler?= , Dennis Muhlestein On Wednesday 10 November 2004 09:36, stian@nixia.no wrote: > > This fact (glibc caches getpid() results) was even known because already > > posted, and I guessed that this could happen only with TLS support. > > That glibc caches getpid() has been a known issue before when people > wanted to benchmark uml syscall speeds inside vs outside of UML using a > simple libc-function. In fact, it has been also said against SYSEMU benchmarks. Actually, it was obvious it didn't apply: in fact, this only happens with TLS, which is always disabled inside UML. > A clone() call can't easily invalidate caches around > in libs that are stored in statics. But it should be mentioned on > getpid()'s man/info page that the value might be cached. > Perhaps sende the glibc dudes an email with the problem, and either get > them to remove the cache or document it. Either way it will be a problem, > since people might use a version of glibc then that caches getpid.. only > work-around is to use syscall() directly, or avoid using getpid() before > clone(). The first one is better, I'm going to use it. Bye -- Paolo Giarrusso, aka Blaisorblade Linux registered user n. 292729 ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel