From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f71.google.com (mail-pl0-f71.google.com [209.85.160.71]) by kanga.kvack.org (Postfix) with ESMTP id D104E6B02B3 for ; Tue, 15 May 2018 12:00:11 -0400 (EDT) Received: by mail-pl0-f71.google.com with SMTP id ay8-v6so333091plb.9 for ; Tue, 15 May 2018 09:00:11 -0700 (PDT) Received: from aserp2120.oracle.com (aserp2120.oracle.com. [141.146.126.78]) by mx.google.com with ESMTPS id a4-v6si325536plp.219.2018.05.15.09.00.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 15 May 2018 09:00:07 -0700 (PDT) Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w4FFtwit169879 for ; Tue, 15 May 2018 16:00:04 GMT Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by aserp2120.oracle.com with ESMTP id 2hx29w1456-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 15 May 2018 16:00:04 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w4FG02ir020494 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 15 May 2018 16:00:03 GMT Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w4FG0200019742 for ; Tue, 15 May 2018 16:00:02 GMT Received: by mail-ot0-f179.google.com with SMTP id t1-v6so779859oth.8 for ; Tue, 15 May 2018 09:00:01 -0700 (PDT) MIME-Version: 1.0 References: <20180510115356.31164-1-pasha.tatashin@oracle.com> <20180510123039.GF5325@dhcp22.suse.cz> <20180515091036.GC12670@dhcp22.suse.cz> <20180515125541.GH12670@dhcp22.suse.cz> In-Reply-To: <20180515125541.GH12670@dhcp22.suse.cz> From: Pavel Tatashin Date: Tue, 15 May 2018 11:59:25 -0400 Message-ID: Subject: Re: [PATCH v2] mm: allow deferred page init for vmemmap only Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: mhocko@kernel.org Cc: Steven Sistare , Daniel Jordan , Andrew Morton , LKML , tglx@linutronix.de, Linux Memory Management List , mgorman@techsingularity.net, mingo@kernel.org, peterz@infradead.org, Steven Rostedt , Fengguang Wu , Dennis Zhou > This will always be a maze as the early boot tends to be. Sad but true. > That is why I am not really convinced we should use a large hammer and > disallow deferred page initialization just because UP implementation of > pcp does something too early. We should instead rule that one odd case. > Your patch simply doesn't rule a large class of potential issues. It > just rules out a potentially useful feature for an odd case. See my > point? Hi Michal, OK, I will send an updated patch with disabling deferred pages only whe NEED_PER_CPU_KM. Hopefully, we won't see similar issues in other places. Thank you, Pavel