From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by zproxy.gmail.com with SMTP id k1so345985nzf for ; Fri, 21 Oct 2005 00:25:59 -0700 (PDT) Message-ID: Date: Fri, 21 Oct 2005 16:25:59 +0900 From: Magnus Damm Subject: Re: [PATCH 1/4] Swap migration V3: LRU operations In-Reply-To: <1129877795.26533.12.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Content-Disposition: inline References: <20051020225935.19761.57434.sendpatchset@schroedinger.engr.sgi.com> <20051020225940.19761.93396.sendpatchset@schroedinger.engr.sgi.com> <1129874762.26533.5.camel@localhost> <1129877795.26533.12.camel@localhost> Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Hansen Cc: Christoph Lameter , Andrew Morton , Mike Kravetz , Linux Kernel Mailing List , linux-mm , Marcelo Tosatti List-ID: On 10/21/05, Dave Hansen wrote: > On Fri, 2005-10-21 at 15:27 +0900, Magnus Damm wrote: > > On 10/21/05, Dave Hansen wrote: > > > On Thu, 2005-10-20 at 15:59 -0700, Christoph Lameter wrote: > > > > + * 0 = page not on LRU list > > > > + * 1 = page removed from LRU list > > > > + * -1 = page is being freed elsewhere. > > > > + */ > > > > > > Can these return values please get some real names? I just hate when > > > things have more than just fail and success as return codes. > > > > > > It makes much more sense to have something like: > > > > > > if (ret == ISOLATION_IMPOSSIBLE) { > > > > Absolutely. But this involves figuring out nice names that everyone > > likes and that does not pollute the name space too much. > > So, your excuse for bad code is that you want to avoid a discussion? > Are you new here? ;) No and yes. =) To me, broken code is bad code. If code looks good or not is another issue. Anyway, I fully agree that using constants are better than hard coded values. I just prefer to stay out of naming discussions. They tend to go on forever and I find them pointless. > > Any suggestions? > > I'd start with the comment, and work from there. > > ISOLATE_PAGE_NOT_LRU > ISOLATE_PAGE_REMOVED_FROM_LRU > ISOLATE_PAGE_FREEING_ELSEWHERE > > Not my best names in history, but probably a place to start. It keeps > the author from having to add bad comments explaining what the code > does. Thank you for that suggestion. > > > BTW, it would probably be nice to say where these patches came from > > > before Magnus. :) > > > > Uh? Yesterday I broke out code from isolate_lru_pages() and > > shrink_cache() and emailed Christoph privately. Do you have similar > > code in your tree? > > Hirokazu's page migration patches have some functions called the exact > same things: __putback_page_to_lru, etc... although they are simpler. I saw that akpm commented regarding duplicated code and I figured it would be better to break out these functions. And if someone has written similar code before then it is probably a good sign saying that something similar is needed. > Not my code, but it would be nice to acknowledge if ideas were coming > from there. Yeah, thanks for stating the obvious. / magnus -- 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