From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id 9F8766B00E8 for ; Tue, 28 Jun 2011 12:59:54 -0400 (EDT) Subject: Re: [PATCH 2/2] mm: Document handle_mm_fault() From: Steven Rostedt In-Reply-To: <20110628165303.010143380@goodmis.org> References: <20110628164750.281686775@goodmis.org> <20110628165303.010143380@goodmis.org> Content-Type: text/plain; charset="ISO-8859-15" Date: Tue, 28 Jun 2011 12:59:52 -0400 Message-ID: <1309280392.26417.5.camel@gandalf.stny.rr.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Andrew Morton , Linus Torvalds , Russell King , Thomas Gleixner , Peter Zijlstra , Gleb Natapov , Hugh Dickins , Rik van Riel , Michel Lespinasse , Avi Kivity , Marcelo Tosatti On Tue, 2011-06-28 at 12:47 -0400, Steven Rostedt wrote: > - > mm/memory.c | 22 ++++++++++++++++++++-- > 1 files changed, 20 insertions(+), 2 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index 5371b5e..3cf30f6 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3378,8 +3378,26 @@ unlock: > return 0; > } > > -/* > - * By the time we get here, we already hold the mm semaphore > +/** > + * handle_mm_fault - main routine for handling page faults > + * @mm: the mm_struct of the target address space > + * @vma: vm_area_struct holding the applicable pages > + * @address: the address that took the fault > + * @flags: flags modifying lookup behaviour > + * > + * Must have @mm->mmap_sem held. > + * > + * Note: if @flags has FAULT_FLAG_ALLOW_RETRY set then the mmap_sem > + * may be released if it failed to arquire the page_lock. If the s/arquire/acquire/ Hmm, I thought I fixed that. I better test the first patch again, in case it has issues in it that I thought I fixed. -- Steve > + * mmap_sem is released then it will return VM_FAULT_RETRY set. > + * This is to keep the time mmap_sem is held when the page_lock > + * is taken for IO. > + * Exception: If FAULT_FLAG_RETRY_NOWAIT is set, then it will > + * not release the mmap_sem, but will still return VM_FAULT_RETRY > + * if it failed to acquire the page_lock. > + * This is for helping virtualization. See get_user_page_nowait(). > + * > + * Returns status flags based on the VM_FAULT_* flags in > */ > int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, > unsigned long address, unsigned int flags) -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org