From: Jerome Glisse <jglisse@redhat.com>
To: David Hildenbrand <david@redhat.com>
Cc: osalvador@techadventures.net, akpm@linux-foundation.org,
mhocko@suse.com, dan.j.williams@intel.com,
pasha.tatashin@oracle.com, yasu.isimatu@gmail.com,
logang@deltatee.com, dave.jiang@intel.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, Oscar Salvador <osalvador@suse.de>
Subject: Re: [RFC PATCH 2/3] mm/memory_hotplug: Create __shrink_pages and move it to offline_pages
Date: Tue, 7 Aug 2018 11:19:57 -0400 [thread overview]
Message-ID: <20180807151957.GC3301@redhat.com> (raw)
In-Reply-To: <a6e4e654-fc95-497f-16f3-8c1550cf03d6@redhat.com>
On Tue, Aug 07, 2018 at 04:54:57PM +0200, David Hildenbrand wrote:
> On 07.08.2018 15:52, Jerome Glisse wrote:
> > On Tue, Aug 07, 2018 at 03:37:56PM +0200, osalvador@techadventures.net wrote:
> >> From: Oscar Salvador <osalvador@suse.de>
> >
> > [...]
> >
> >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> >> index 9bd629944c91..e33555651e46 100644
> >> --- a/mm/memory_hotplug.c
> >> +++ b/mm/memory_hotplug.c
> >
> > [...]
> >
> >> /**
> >> * __remove_pages() - remove sections of pages from a zone
> >> - * @zone: zone from which pages need to be removed
> >> + * @nid: node which pages belong to
> >> * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
> >> * @nr_pages: number of pages to remove (must be multiple of section size)
> >> * @altmap: alternative device page map or %NULL if default memmap is used
> >> @@ -548,7 +557,7 @@ static int __remove_section(struct zone *zone, struct mem_section *ms,
> >> * sure that pages are marked reserved and zones are adjust properly by
> >> * calling offline_pages().
> >> */
> >> -int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
> >> +int __remove_pages(int nid, unsigned long phys_start_pfn,
> >> unsigned long nr_pages, struct vmem_altmap *altmap)
> >> {
> >> unsigned long i;
> >> @@ -556,10 +565,9 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
> >> int sections_to_remove, ret = 0;
> >>
> >> /* In the ZONE_DEVICE case device driver owns the memory region */
> >> - if (is_dev_zone(zone)) {
> >> - if (altmap)
> >> - map_offset = vmem_altmap_offset(altmap);
> >> - } else {
> >> + if (altmap)
> >> + map_offset = vmem_altmap_offset(altmap);
> >> + else {
> >
> > This will break ZONE_DEVICE at least for HMM. While i think that
> > altmap -> ZONE_DEVICE (ie altmap imply ZONE_DEVICE) the reverse
> > is not true ie ZONE_DEVICE does not necessarily imply altmap. So
> > with the above changes you change the expected behavior. You do
> > need the zone to know if it is a ZONE_DEVICE. You could also lookup
> > one of the struct page but my understanding is that this is what
> > you want to avoid in the first place.
>
> I wonder if we could instead forward from the callers whether we are
> dealing with ZONE_DEVICE memory (is_device ...), at least that seems
> feasible in hmm code. Not having looked at details yet.
>
Yes i believe this is doable, this add one more argument, to me it
looked like passing down the zone was good idea, i think with the
struct zone you can even remove the altmap argument.
Is there a reason why you do not want to pass down the struct zone ?
Cheers,
Jérôme
next prev parent reply other threads:[~2018-08-07 15:20 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-07 13:37 [RFC PATCH 0/3] Do not touch pages in remove_memory path osalvador
2018-08-07 13:37 ` [RFC PATCH 1/3] mm/memory_hotplug: Add nid parameter to arch_remove_memory osalvador
2018-08-07 13:37 ` [RFC PATCH 2/3] mm/memory_hotplug: Create __shrink_pages and move it to offline_pages osalvador
2018-08-07 13:52 ` Jerome Glisse
2018-08-07 14:54 ` David Hildenbrand
2018-08-07 15:19 ` Jerome Glisse [this message]
2018-08-07 15:28 ` David Hildenbrand
2018-08-07 20:48 ` Oscar Salvador
2018-08-07 22:13 ` Jerome Glisse
2018-08-08 7:38 ` Oscar Salvador
2018-08-08 7:45 ` David Hildenbrand
2018-08-08 7:56 ` Oscar Salvador
2018-08-08 8:08 ` David Hildenbrand
2018-08-08 13:42 ` Oscar Salvador
2018-08-08 17:55 ` Jerome Glisse
2018-08-08 21:29 ` Oscar Salvador
2018-08-09 7:50 ` Oscar Salvador
2018-08-09 7:52 ` Oscar Salvador
2018-08-08 7:51 ` David Hildenbrand
2018-08-08 8:00 ` Oscar Salvador
2018-08-07 14:59 ` Michal Hocko
2018-08-07 15:18 ` Jerome Glisse
2018-08-08 6:47 ` Michal Hocko
2018-08-08 16:58 ` Jerome Glisse
2018-08-08 21:28 ` Oscar Salvador
2018-08-09 8:24 ` Michal Hocko
2018-08-09 14:27 ` Jerome Glisse
2018-08-09 15:09 ` Michal Hocko
2018-08-09 16:58 ` Jerome Glisse
2018-08-09 20:50 ` Oscar Salvador
2018-08-16 14:58 ` Oscar Salvador
2018-08-16 17:32 ` Jerome Glisse
2018-08-08 9:45 ` Oscar Salvador
2018-08-08 17:33 ` Jerome Glisse
2018-08-07 13:37 ` [RFC PATCH 3/3] mm/memory_hotplug: Refactor shrink_zone/pgdat_span osalvador
2018-08-07 14:16 ` [RFC PATCH 0/3] Do not touch pages in remove_memory path David Hildenbrand
2018-08-07 14:19 ` Oscar Salvador
2018-08-07 14:20 ` David Hildenbrand
2018-08-07 14:28 ` Oscar Salvador
2018-08-07 14:41 ` David Hildenbrand
2018-08-07 14:52 ` Oscar Salvador
2018-08-15 14:05 ` Pavel Tatashin
2018-08-15 14:32 ` 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=20180807151957.GC3301@redhat.com \
--to=jglisse@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=dan.j.williams@intel.com \
--cc=dave.jiang@intel.com \
--cc=david@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=logang@deltatee.com \
--cc=mhocko@suse.com \
--cc=osalvador@suse.de \
--cc=osalvador@techadventures.net \
--cc=pasha.tatashin@oracle.com \
--cc=yasu.isimatu@gmail.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).