From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yang Shi Subject: Re: [PATCH] move_pages.2: not return ENOENT if the page are already on the target nodes Date: Mon, 30 Dec 2019 18:49:29 -0800 Message-ID: <51a37061-8d95-eca1-a1d9-e6e8f4dc884d@linux.alibaba.com> References: <1575596090-115377-1-git-send-email-yang.shi@linux.alibaba.com> <0dc96e40-5f2b-a2fe-6e5f-b6f3d5e9ebde@nvidia.com> <95170ea5-5b62-9168-fcd9-93b43330a1b4@linux.alibaba.com> <092adc11-7039-9343-7067-0e0199c9dc13@gmail.com> <51dd767a-221f-882d-c7f6-45bd0c217a67@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <51dd767a-221f-882d-c7f6-45bd0c217a67@nvidia.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: John Hubbard , "Michael Kerrisk (man-pages)" , cl@linux.com, mhocko@suse.com, cai@lca.pw, akpm@linux-foundation.org Cc: linux-man@vger.kernel.org, linux-api@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-Id: linux-api@vger.kernel.org On 12/17/19 11:36 PM, John Hubbard wrote: > On 12/13/19 5:55 PM, Michael Kerrisk (man-pages) wrote: > ... >>>> whoa, hold on. If I'm reading through the various error paths >>>> correctly, then this >>>> code is *never* going to return ENOENT for the whole function. It can >>>> fill in that >>>> value per-page, in the status array, but that's all. Did I get that >>>> right? >>> >>> Nice catch. Yes, you are right. >>> >>>> >>>> If so, we need to redo this part of the man page. >>> >>> Yes. >> >> So where are things at with this? Is an improved man-pages >> patch on the way, or is some other action (on the API) planned? >> > > I was waiting to see if Yang was going to respond...anyway, I think > we're looking at approximately this sort of change: > Hi John, I apologize for the delay, just came back from vacation. Thanks for taking care of the patch. > diff --git a/man2/move_pages.2 b/man2/move_pages.2 > index 2d96468fa..1bf1053f2 100644 > --- a/man2/move_pages.2 > +++ b/man2/move_pages.2 > @@ -191,12 +191,6 @@ was specified or an attempt was made to migrate > pages of a kernel thread. >  .B ENODEV >  One of the target nodes is not online. >  .TP > -.B ENOENT > -No pages were found that require moving. > -All pages are either already > -on the target node, not present, had an invalid address or could not be > -moved because they were mapped by multiple processes. > -.TP >  .B EPERM >  The caller specified >  .B MPOL_MF_MOVE_ALL > > ...But I'm not sure if we should change the implementation, instead, so > that it *can* return ENOENT. That's the main question to resolve before > creating any more patches, I think. > > In addition, Michal mentioned that the page states in the status array > also > need updated documentation. > > > thanks,