From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: Question on the five-level page table support patches Date: Mon, 24 Apr 2017 06:03:11 -0700 Message-ID: <20170424130311.GR4021@tassilo.jf.intel.com> References: <030ea57b-5f6c-13d8-02f7-b245a754a87d@physik.fu-berlin.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Andy Lutomirski Cc: John Paul Adrian Glaubitz , "Kirill A. Shutemov" , "linux-kernel@vger.kernel.org" , Dave Hansen , Michal Hocko , linux-arch , "linux-mm@kvack.org" List-Id: linux-arch.vger.kernel.org > Can you explain what the issue is? What used to work on Linux and > doesn't any more? The man page is quite clear: In old Linux hint was a search hint, so if there isn't a hole at the hinted area it will search starting from there for a hole instead of giving up immediately. Now it just gives up, which means every user has to implement their own search. Yes I ran into the same problem and it's annoying. It broke originally when top down mmap was added I believe Before the augmented rbtree it was potentially very expensive, but now it should be cheap. -Andi From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com ([134.134.136.20]:1789 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1170543AbdDXNDR (ORCPT ); Mon, 24 Apr 2017 09:03:17 -0400 Date: Mon, 24 Apr 2017 06:03:11 -0700 From: Andi Kleen Subject: Re: Question on the five-level page table support patches Message-ID: <20170424130311.GR4021@tassilo.jf.intel.com> References: <030ea57b-5f6c-13d8-02f7-b245a754a87d@physik.fu-berlin.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andy Lutomirski Cc: John Paul Adrian Glaubitz , "Kirill A. Shutemov" , "linux-kernel@vger.kernel.org" , Dave Hansen , Michal Hocko , linux-arch , "linux-mm@kvack.org" Message-ID: <20170424130311.EZrF-oOTHWREa9OxTlMeYhGdNqbizQlz86G9BBJESoo@z> > Can you explain what the issue is? What used to work on Linux and > doesn't any more? The man page is quite clear: In old Linux hint was a search hint, so if there isn't a hole at the hinted area it will search starting from there for a hole instead of giving up immediately. Now it just gives up, which means every user has to implement their own search. Yes I ran into the same problem and it's annoying. It broke originally when top down mmap was added I believe Before the augmented rbtree it was potentially very expensive, but now it should be cheap. -Andi