From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Aspinall Subject: Re: Threading in linux Date: Tue, 24 Apr 2007 20:48:51 -0400 Message-ID: <462EA573.8020509@rcn.com> References: <7783925d0704232338h52bc1180i435a880b267ca0f3@mail.gmail.com> <8bd0f97a0704240308g6428f153n3bf4a2ae5518398a@mail.gmail.com> <7783925d0704240336i49e918dcm4d38e9bbc0310a39@mail.gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <7783925d0704240336i49e918dcm4d38e9bbc0310a39@mail.gmail.com> Sender: linux-newbie-owner@vger.kernel.org List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Rick Brown Cc: kernelnewbies , linux-newbie@vger.kernel.org Rick Brown wrote: > > Could you hint upon the kernel features required for NPTL? May be a link? I know very little about this, but by coincidence (the application program I work on got a nice bugfix because of this) I can tell you one kernel difference on x86_64 kernels that support NPTL. For NPTL on x86_64, the kernel reserves a register for thread-ID. That register is swapped as part of the context switch the kernel does. In the older LinuxThreads, thread-ID was established by looking up a stack address in a table. In the LinuxThreads implementation, thread-ID was broken whenever a thread ran on the alt-stack. John Aspinall - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs