From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC] page fault retry with NOPAGE_RETRY From: Benjamin Herrenschmidt In-Reply-To: <45107ECE.5040603@google.com> References: <1158274508.14473.88.camel@localhost.localdomain> <20060915001151.75f9a71b.akpm@osdl.org> <45107ECE.5040603@google.com> Content-Type: text/plain Date: Wed, 20 Sep 2006 09:50:35 +1000 Message-Id: <1158709835.6002.203.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Mike Waychison Cc: Andrew Morton , linux-mm@kvack.org, Linux Kernel list , Linus Torvalds List-ID: On Tue, 2006-09-19 at 16:35 -0700, Mike Waychison wrote: > Patch attached. > > As Andrew points out, the logic is a bit hacky and using a flag in > current->flags to determine whether we have done the retry or not already. > > I too think the right approach to being able to handle these kinds of > retries in a more general fashion is to introduce a struct > pagefault_args along the page faulting path. Within it, we could > introduce a reason for the retry so the higher levels would be able to > better understand what to do. .../... I need to re-read your mail and Andrew as at this point, I don't quite see why we need that args and/or that current->flags bit instead of always returning all the way to userland and let the faulting instruction happen again (which means you don't block in the kernel, can take signals etc... thus do you actually need to prevent multiple retries ?) 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://www.linux-mm.org/ . Don't email: email@kvack.org