linux-kernel - Re: [PATCH 11/14] mm, memory_hotplug: do not associate hotadded memory to zones until online

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20170616091117.GA4716@WeideMacBook-Pro.local>
Date:   Fri, 16 Jun 2017 17:11:17 +0800
From:   Wei Yang <richard.weiyang@...il.com>
To:     Michal Hocko <mhocko@...nel.org>
Cc:     Wei Yang <richard.weiyang@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
        Mel Gorman <mgorman@...e.de>, Vlastimil Babka <vbabka@...e.cz>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Jerome Glisse <jglisse@...hat.com>,
        Reza Arbab <arbab@...ux.vnet.ibm.com>,
        Yasuaki Ishimatsu <yasu.isimatu@...il.com>,
        qiuxishi@...wei.com, Kani Toshimitsu <toshi.kani@....com>,
        slaoub@...il.com, Joonsoo Kim <js1304@...il.com>,
        Andi Kleen <ak@...ux.intel.com>,
        David Rientjes <rientjes@...gle.com>,
        Daniel Kiper <daniel.kiper@...cle.com>,
        Igor Mammedov <imammedo@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Heiko Carstens <heiko.carstens@...ibm.com>,
        Martin Schwidefsky <schwidefsky@...ibm.com>
Subject: Re: [PATCH 11/14] mm, memory_hotplug: do not associate hotadded
 memory to zones until online

On Fri, Jun 16, 2017 at 10:45:55AM +0200, Michal Hocko wrote:
>On Fri 16-06-17 16:11:42, Wei Yang wrote:
>> Well, I love this patch a lot. We don't need to put the hotadd memory in one
>> zone and move it to another. This looks great!
>> 
>> On Mon, May 15, 2017 at 10:58:24AM +0200, Michal Hocko wrote:
>> >From: Michal Hocko <mhocko@...e.com>
>> >
>> [...]
>> +
>> >+void move_pfn_range_to_zone(struct zone *zone,
>> >+		unsigned long start_pfn, unsigned long nr_pages)
>> >+{
>> >+	struct pglist_data *pgdat = zone->zone_pgdat;
>> >+	int nid = pgdat->node_id;
>> >+	unsigned long flags;
>> >+	unsigned long i;
>> >+
>> >+	if (zone_is_empty(zone))
>> >+		init_currently_empty_zone(zone, start_pfn, nr_pages);
>> >+
>> >+	clear_zone_contiguous(zone);
>> >+
>> >+	/* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */
>> >+	pgdat_resize_lock(pgdat, &flags);
>> >+	zone_span_writelock(zone);
>> >+	resize_zone_range(zone, start_pfn, nr_pages);
>> >+	zone_span_writeunlock(zone);
>> >+	resize_pgdat_range(pgdat, start_pfn, nr_pages);
>> >+	pgdat_resize_unlock(pgdat, &flags);
>> >+
>> >+	/*
>> >+	 * TODO now we have a visible range of pages which are not associated
>> >+	 * with their zone properly. Not nice but set_pfnblock_flags_mask
>> >+	 * expects the zone spans the pfn range. All the pages in the range
>> >+	 * are reserved so nobody should be touching them so we should be safe
>> >+	 */
>> >+	memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, MEMMAP_HOTPLUG);
>> >+	for (i = 0; i < nr_pages; i++) {
>> >+		unsigned long pfn = start_pfn + i;
>> >+		set_page_links(pfn_to_page(pfn), zone_idx(zone), nid, pfn);
>> > 	}
>> 
>> memmap_init_zone()->__init_single_page()->set_page_links()
>> 
>> Do I miss something that you call set_page_links() explicitly here?
>
>I guess you are right. Not sure why I've done this explicitly. I've most
>probably just missed that. Could you post a patch that removes the for
>loop.
>

Sure, I will come up with two patches based on you auto-latest branch.

>Thanks!
>-- 
>Michal Hocko
>SUSE Labs

-- 
Wei Yang
Help you, Help me

Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)