From: Baoquan He <bhe@redhat.com> To: David Hildenbrand <david@redhat.com> Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, x86@kernel.org, Andrew Morton <akpm@linux-foundation.org>, Oscar Salvador <osalvador@suse.de>, Michal Hocko <mhocko@suse.com>, Pavel Tatashin <pasha.tatashin@soleen.com>, Dan Williams <dan.j.williams@intel.com>, Wei Yang <richardw.yang@linux.intel.com> Subject: Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span() Date: Wed, 5 Feb 2020 21:34:42 +0800 Message-ID: <20200205133442.GC8965@MiWiFi-R3L-srv> (raw) In-Reply-To: <cd353848-301a-025d-dd66-44d76e1bbc44@redhat.com> On 02/05/20 at 02:20pm, David Hildenbrand wrote: > On 05.02.20 13:43, Baoquan He wrote: > > On 02/04/20 at 03:42pm, David Hildenbrand wrote: > >> On 04.02.20 15:25, Baoquan He wrote: > >>> On 10/06/19 at 10:56am, David Hildenbrand wrote: > >>>> If we have holes, the holes will automatically get detected and removed > >>>> once we remove the next bigger/smaller section. The extra checks can > >>>> go. > >>>> > >>>> Cc: Andrew Morton <akpm@linux-foundation.org> > >>>> Cc: Oscar Salvador <osalvador@suse.de> > >>>> Cc: Michal Hocko <mhocko@suse.com> > >>>> Cc: David Hildenbrand <david@redhat.com> > >>>> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> > >>>> Cc: Dan Williams <dan.j.williams@intel.com> > >>>> Cc: Wei Yang <richardw.yang@linux.intel.com> > >>>> Signed-off-by: David Hildenbrand <david@redhat.com> > >>>> --- > >>>> mm/memory_hotplug.c | 34 +++++++--------------------------- > >>>> 1 file changed, 7 insertions(+), 27 deletions(-) > >>>> > >>>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > >>>> index f294918f7211..8dafa1ba8d9f 100644 > >>>> --- a/mm/memory_hotplug.c > >>>> +++ b/mm/memory_hotplug.c > >>>> @@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > >>>> if (pfn) { > >>>> zone->zone_start_pfn = pfn; > >>>> zone->spanned_pages = zone_end_pfn - pfn; > >>>> + } else { > >>>> + zone->zone_start_pfn = 0; > >>>> + zone->spanned_pages = 0; > >>>> } > >>>> } else if (zone_end_pfn == end_pfn) { > >>>> /* > >>>> @@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > >>>> start_pfn); > >>>> if (pfn) > >>>> zone->spanned_pages = pfn - zone_start_pfn + 1; > >>>> + else { > >>>> + zone->zone_start_pfn = 0; > >>>> + zone->spanned_pages = 0; > >>> > >>> Thinking in which case (zone_start_pfn != start_pfn) and it comes here. > >> > >> Could only happen in case the zone_start_pfn would have been "out of the > >> zone already". If you ask me: unlikely :) > > > > Yeah, I also think it's unlikely to come here. > > > > The 'if (zone_start_pfn == start_pfn)' checking also covers the case > > (zone_start_pfn == start_pfn && zone_end_pfn == end_pfn). So this > > zone_start_pfn/spanned_pages resetting can be removed to avoid > > confusion. > > At least I would find it more confusing without it (or want a comment > explaining why this does not have to be handled and why the !pfn case is > not possible). I don't get why being w/o it will be more confusing, but it's OK since it doesn't impact anything. > > Anyhow, that patch is already upstream and I don't consider this high > priority. Thanks :) Yeah, noticed you told Wei the status in another patch thread, I am fine with it, just leave it to you to decide. Thanks.
next prev parent reply index Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-10-06 8:56 [PATCH v6 00/10] mm/memory_hotplug: Shrink zones before removing memory David Hildenbrand 2019-10-06 8:56 ` [PATCH v6 01/10] mm/memunmap: Don't access uninitialized memmap in memunmap_pages() David Hildenbrand 2019-10-06 19:58 ` Damian Tometzki 2019-10-06 20:13 ` David Hildenbrand 2019-10-14 9:05 ` David Hildenbrand 2019-10-06 8:56 ` [PATCH v6 02/10] mm/memmap_init: Update variable name in memmap_init_zone David Hildenbrand 2019-10-06 8:56 ` [PATCH v6 03/10] mm/memory_hotplug: Don't access uninitialized memmaps in shrink_pgdat_span() David Hildenbrand 2019-10-14 9:31 ` David Hildenbrand 2019-10-06 8:56 ` [PATCH v6 04/10] mm/memory_hotplug: Don't access uninitialized memmaps in shrink_zone_span() David Hildenbrand 2019-10-14 9:32 ` David Hildenbrand 2019-10-14 19:17 ` Andrew Morton 2019-11-19 14:16 ` David Hildenbrand 2019-11-19 20:44 ` Andrew Morton 2019-10-06 8:56 ` [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory David Hildenbrand 2019-10-14 9:39 ` David Hildenbrand 2019-10-14 19:16 ` Andrew Morton 2019-10-27 22:45 ` David Hildenbrand 2019-11-30 23:21 ` Andrew Morton 2019-11-30 23:43 ` David Hildenbrand 2019-12-18 17:08 ` David Hildenbrand 2019-12-18 20:16 ` Andrew Morton 2019-12-03 15:10 ` Oscar Salvador 2019-12-03 15:27 ` David Hildenbrand 2019-10-06 8:56 ` [PATCH v6 06/10] mm/memory_hotplug: Poison memmap in remove_pfn_range_from_zone() David Hildenbrand 2019-10-16 14:01 ` David Hildenbrand 2020-02-04 8:59 ` Oscar Salvador 2019-10-06 8:56 ` [PATCH v6 07/10] mm/memory_hotplug: We always have a zone in find_(smallest|biggest)_section_pfn David Hildenbrand 2020-02-04 9:06 ` Oscar Salvador 2020-02-05 8:57 ` Wei Yang 2020-02-05 8:59 ` David Hildenbrand 2020-02-05 9:26 ` Wei Yang 2019-10-06 8:56 ` [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span() David Hildenbrand 2020-02-04 9:13 ` Oscar Salvador 2020-02-04 9:20 ` David Hildenbrand 2020-02-04 14:25 ` Baoquan He 2020-02-04 14:42 ` David Hildenbrand 2020-02-05 12:43 ` Baoquan He 2020-02-05 13:20 ` David Hildenbrand 2020-02-05 13:34 ` Baoquan He [this message] 2020-02-05 13:38 ` David Hildenbrand 2020-02-05 14:12 ` Baoquan He 2020-02-05 14:16 ` David Hildenbrand 2020-02-05 14:26 ` Baoquan He 2020-02-05 9:59 ` Wei Yang 2020-02-05 14:48 ` Baoquan He 2020-02-05 22:56 ` Wei Yang 2020-02-05 23:08 ` Baoquan He 2020-02-05 23:26 ` Wei Yang 2020-02-05 23:30 ` Baoquan He 2020-02-05 23:34 ` Wei Yang 2020-02-05 14:54 ` David Laight 2020-02-05 14:55 ` David Hildenbrand 2019-10-06 8:56 ` [PATCH v6 09/10] mm/memory_hotplug: Drop local variables " David Hildenbrand 2020-02-04 9:26 ` Oscar Salvador 2020-02-04 9:29 ` David Hildenbrand 2020-02-05 10:07 ` Wei Yang 2019-10-06 8:56 ` [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages() David Hildenbrand 2020-02-04 9:46 ` Oscar Salvador 2020-02-04 12:41 ` David Hildenbrand 2020-02-04 13:13 ` Segher Boessenkool 2020-02-04 13:38 ` David Hildenbrand 2020-02-05 12:51 ` Segher Boessenkool 2020-02-05 13:17 ` David Hildenbrand 2020-02-05 13:18 ` David Hildenbrand 2020-02-05 13:23 ` David Hildenbrand 2020-02-05 11:48 ` Wei Yang 2019-12-02 9:09 ` [PATCH v6 00/10] mm/memory_hotplug: Shrink zones before removing memory David Hildenbrand 2019-12-03 13:36 ` Oscar Salvador 2020-01-31 4:40 ` Andrew Morton 2020-01-31 9:18 ` David Hildenbrand 2020-01-31 10:03 ` Michal Hocko 2020-01-31 10:36 ` David Hildenbrand 2020-02-04 1:46 ` Andrew Morton 2020-02-04 8:45 ` David Hildenbrand 2020-02-04 9:51 ` Oscar Salvador
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200205133442.GC8965@MiWiFi-R3L-srv \ --to=bhe@redhat.com \ --cc=akpm@linux-foundation.org \ --cc=dan.j.williams@intel.com \ --cc=david@redhat.com \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-ia64@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=linux-s390@vger.kernel.org \ --cc=linux-sh@vger.kernel.org \ --cc=linuxppc-dev@lists.ozlabs.org \ --cc=mhocko@suse.com \ --cc=osalvador@suse.de \ --cc=pasha.tatashin@soleen.com \ --cc=richardw.yang@linux.intel.com \ --cc=x86@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Linux-mm Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \ linux-mm@kvack.org public-inbox-index linux-mm Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.kvack.linux-mm AGPL code for this site: git clone https://public-inbox.org/public-inbox.git