From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <380FB40C.16662EDA@263.net> Date: Fri, 22 Oct 1999 08:47:08 +0800 From: Wang Yong Reply-To: wung_y@263.net MIME-Version: 1.0 Subject: Re: page faults References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: mail list linux-mm mail list List-ID: the page fault is an interrupt and do_page_fault is the handler, so no other page fault will be received in do_page_fault. this is true for linux because it's not preemptive. if the page fault is caused by a write to a shared page, do_wp_page will be called to copy this page to a new page(copy on write). "Benjamin C.R. LaHaise" wrote: > On Thu, 21 Oct 1999, James Simmons wrote: > > > Quick question. If two processes are sharing the same memory but no page > > fault has happened. THen process A causes a page fault. If process B tries > > to access the page that process A already page fault will process B cause > > another page fault. Or do page faults only happen once no matter how many > > process access it. > > Only the first time the page is accessed is there a fault to put the entry > into the page table, regardless of the processes sharing the page. The > only time entries are removed from a process' page tables is on fork > (ie marking private pages read only so COW works), unmap or vmscan's page > reclaims. > > -ben > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://humbolt.geo.uu.nl/Linux-MM/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/