From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by gxk8 with SMTP id 8so12143572gxk.14 for ; Tue, 30 Sep 2008 20:13:44 -0700 (PDT) Message-ID: Date: Tue, 30 Sep 2008 20:13:44 -0700 From: "Ulrich Drepper" Subject: Re: [PATCH 0/4] futex: get_user_pages_fast() for shared futexes In-Reply-To: <48E205BE.8030908@cosmosbay.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080926173219.885155151@twins.programming.kicks-ass.net> <20080927161712.GA1525@elte.hu> <200809301721.52148.nickpiggin@yahoo.com.au> <1222764669.12646.26.camel@twins.programming.kicks-ass.net> <48E205BE.8030908@cosmosbay.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Eric Dumazet Cc: Peter Zijlstra , Nick Piggin , Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Tue, Sep 30, 2008 at 3:55 AM, Eric Dumazet wrote: > I am not sure how it could be converted to private futexes, since > old binaries (static glibc) will use FUTEX_WAKE like calls. We considered this back when but any effort seems too much. We'd either need a clone flag (a scarce resource) or replace the set_tid _address syscall. Given that the futex is woken once per thread lifetime it shouldn't be an issue. If the semaphore shows up even after this patch feel free to introduce a new set_tid_address syscall. -- 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