From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 13 Aug 2008 11:16:35 -0700 From: Arjan van de Ven Subject: Re: pthread_create() slow for many threads; also time to revisit 64b context switch optimization? Message-ID: <20080813111635.657febc0@infradead.org> In-Reply-To: <48A3222D.2060809@redhat.com> References: <20080813104445.GA24632@elte.hu> <20080813063533.444c650d@infradead.org> <48A2EE07.3040003@redhat.com> <20080813142529.GB21129@elte.hu> <48A2F157.7000303@redhat.com> <20080813151007.GA8780@elte.hu> <48A2FC17.9070302@redhat.com> <20080813154043.GA11886@elte.hu> <48A303EE.8070002@redhat.com> <48A3222D.2060809@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Ulrich Drepper Cc: Linus Torvalds , Ingo Molnar , akpm@linux-foundation.org, hugh@veritas.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, briangrant@google.com, cgd@google.com, mbligh@google.com, Thomas Gleixner , "H. Peter Anvin" List-ID: On Wed, 13 Aug 2008 11:04:29 -0700 Ulrich Drepper wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Linus Torvalds wrote: > > Ulrich, I don't understand why you worry more about a _potential_ > > (and fairly unlikely) complaint, than about a real one today. > > Of course I care. All I try to do is to prevent going from one > extreme (all focus on P4s) to the other (ignore P4s completely). (fwiw as far as I know this is only about early 64 bit P4s, not later generations) > > Even ignoring this one case here, I think it's in any case useful for > userlevel to tell the kernel that an anonymous memory region is needed > for a stack. This might allow better optimizations and/or security > implementations. yeah maybe we should also tell it we expect it to be used downwards. Oh wait.. MAP_GROWSDOWN ? -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org