From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1FMq8K-0007Hb-1K for user-mode-linux-devel@lists.sourceforge.net; Fri, 24 Mar 2006 09:31:32 -0800 Received: from saraswathi.solana.com ([198.99.130.12]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1FMq8I-00021U-Fa for user-mode-linux-devel@lists.sourceforge.net; Fri, 24 Mar 2006 09:31:32 -0800 From: Jeff Dike Subject: Re: [uml-devel] Re: TLS support - status - need for re-testing Message-ID: <20060324173247.GD5400@ccure.user-mode-linux.org> References: <200603230317.48384.blaisorblade@yahoo.it> <200603240044.06196.blaisorblade@yahoo.it> <20060324041724.GB8750@ccure.user-mode-linux.org> <200603241243.34687.blaisorblade@yahoo.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200603241243.34687.blaisorblade@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: Fri, 24 Mar 2006 12:32:47 -0500 To: Blaisorblade Cc: user-mode-linux-devel@lists.sourceforge.net, Antoine Martin On Fri, Mar 24, 2006 at 12:43:33PM +0100, Blaisorblade wrote: > We discussed this time ago, and read the description of the patch: > > # Also, as suggested by Jeff, remove a redundant enabling of SIGVTALRM, > # comprised in the subsequent local_irq_enable(). I'm just a bit dubious if > # ordering matters there... Oops, nevermind. > Note this pre-dates soft interrupts, however. Shouldn't matter. > > global-ldt-sem - We should be using mutexes now, not semaphores > > That's your patch, but below I drop this. My patch predates mutexes. But you still use semaphores, and that should be updated. > > undo-global-ldt-sem - what's so horrible about the global? it won't > > be highly contended, so making a single mutex saves memory from every > > ldt. > > For memory: 500 existing processes (a huge number in practice) * 20 byte (and > I think a semaphore is smaller) = 10 Kbyte. We waste more for the kernel > stack of 1 thread. > > For reason: the compilation problem can be avoided differently (and the > subsequent patch also merges duplicated code). > > I didn't like global_ldt_sem because I felt it unclean; if done for memory > usage it's another story, but still we need to check this creates no locking > problem (almost surely no, but I want to look at the code well). It's simpler. A single global lock is simpler than a lock in every datastructure. Jeff ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel