From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <44D75526.4050108@yahoo.com.au> Date: Tue, 08 Aug 2006 00:58:46 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [patch][rfc] possible lock_page fix for Andrea's nopage vs invalidate race? References: <44CF3CB7.7030009@yahoo.com.au> <44D74B98.3030305@yahoo.com.au> In-Reply-To: <44D74B98.3030305@yahoo.com.au> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Andrea Arcangeli , Andrew Morton , David Howells , Linux Memory Management List-ID: Nick Piggin wrote: > Hugh Dickins wrote: >> I suppose this is quite efficient, but I find it confusing. >> We have lots and lots of drivers already setting vm_flags in their >> mmap methods, now you add an alternative way of doing the same thing. >> Can't you just set VM_NOPAGE_LOCKED in the relevant mmap methods? >> Or did you try it that way and it worked out messy? > > > Generic pagecache doesn't have an mmap method, which is where > I stopped looking. I guess you could add the |= to filemap_nopage, > but that's much uglier. > > I don't find it at all confusing, just maybe a bit of a violation > because the structure is technically only for "ops". Hmm, I guess adding a new mmap method solely to set that flag would actually be cleaner. And it would allow any filesystems that override .nopage bug end up calling filemap_nopage could equivalently override their mmap but still call filemap_mmap. Yes that might be nicer. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com -- 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