Received-SPF: pass (google.com: best guess record for domain of linux-nfs-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 7 Apr 2020 09:33:42 +0200
From:   Michal Hocko <mhocko@kernel.org>
To:     NeilBrown <neilb@suse.de>
Cc:     Jan Kara <jack@suse.cz>, Christoph Hellwig <hch@infradead.org>,
        Trond Myklebust <trondmy@hammerspace.com>,
        "Anna.Schumaker@Netapp.com" <Anna.Schumaker@netapp.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-nfs@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2 - v2] MM: Discard NR_UNSTABLE_NFS, use NR_WRITEBACK
 instead.
Message-ID: <20200407071148.GE18914@dhcp22.suse.cz>
References: <87tv2b7q72.fsf@notabene.neil.brown.name>
 <87v9miydai.fsf@notabene.neil.brown.name>
 <87sghmyd8v.fsf@notabene.neil.brown.name>
 <87pncqyd7k.fsf@notabene.neil.brown.name>
 <20200402151009.GA14130@infradead.org>
 <87h7y1y0ra.fsf@notabene.neil.brown.name>
 <20200403094220.GA29920@quack2.suse.cz>
 <87k12sw5ws.fsf@notabene.neil.brown.name>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <87k12sw5ws.fsf@notabene.neil.brown.name>
Sender: linux-nfs-owner@vger.kernel.org
Precedence: bulk

On Tue 07-04-20 09:28:19, Neil Brown wrote:
> On Fri, Apr 03 2020, Jan Kara wrote:
> >
> > So I don't think we can just remove lines from procfs files like this. That
> > has a high potential of breaking some userspace app that is not careful
> > enough when parsing the file. So I think that we need to leave there the
> > format string and just replace K(node_page_state(pgdat, NR_UNSTABLE_NFS))
> > with 0.
> 
> OK.  I assume changing the static trace points isn't a problem though?

It shouldn't be until we learn that somebody depends on it...
-- 
Michal Hocko
SUSE Labs