From: Oscar Salvador <osalvador@techadventures.net>
To: David Hildenbrand <david@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>,
akpm@linux-foundation.org, mhocko@suse.com,
dan.j.williams@intel.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: Wed, 8 Aug 2018 15:42:33 +0200 [thread overview]
Message-ID: <20180808134233.GA10946@techadventures.net> (raw)
In-Reply-To: <7a64e67d-1df9-04ab-cc49-99a39aa90798@redhat.com>
On Wed, Aug 08, 2018 at 10:08:41AM +0200, David Hildenbrand wrote:
> Then it is maybe time to cleary distinguish both types of memory, as
> they are fundamentally different when it comes to online/offline behavior.
>
> Ordinary ram:
> add_memory ...
> online_pages ...
> offline_pages
> remove_memory
>
> Device memory
> add_device_memory ...
> remove_device_memory
>
> So adding/removing from the zone and stuff can be handled there.
Uhm, I have been thinking about this.
Maybe we could do something like (completely untested):
== memory_hotplug code ==
int add_device_memory(int nid, unsigned long start, unsigned long size,
struct vmem_altmap *altmap, bool mapping)
{
int ret;
unsigned long start_pfn = PHYS_PFN(start);
unsigned long nr_pages = size >> PAGE_SHIFT;
mem_hotplug_begin();
if (mapping)
ret = arch_add_memory(nid, start, size, altmap, false)
else
ret = add_pages(nid, start_pfn, nr_pages, altmap, false):
if (!ret) {
pgdata_t *pgdata = NODE_DATA(nid);
struct zone *zone = pgdata->node_zones[ZONE_DEVICE];
online_mem_sections(start_pfn, start_pfn + nr_pages);
move_pfn_range_to_zone(zone, start_pfn, nr_pages, altmap);
}
mem_hotplug_done();
return ret;
}
int del_device_memory(int nid, unsigned long start, unsigned long size,
struct vmem_altmap *altmap, bool mapping)
{
int ret;
unsigned long start_pfn = PHYS_PFN(start);
unsigned long nr_pages = size >> PAGE_SHIFT;
pgdata_t *pgdata = NODE_DATA(nid);
struct zone *zone = pgdata->node_zones[ZONE_DEVICE];
mem_hotplug_begin();
offline_mem_sections(start_pfn, start_pfn + nr_pages);
__shrink_pages(zone, start_pfn, start_pfn + nr_pages, nr_pages);
if (mapping)
ret = arch_remove_memory(nid, start, size, altmap)
else
ret = __remove_pages(nid, start_pfn, nr_pages, altmap)
mem_hotplug_done();
return ret;
}
===
And then, HMM/devm code could use it.
For example:
hmm_devmem_pages_create():
...
...
if (devmem->pagemap.type == MEMORY_DEVICE_PUBLIC)
linear_mapping = true;
else
linear_mapping = false;
ret = add_device_memory(nid, align_start, align_size, NULL, linear_mapping);
if (ret)
goto error_add_memory;
...
...
hmm_devmem_release:
...
...
if (resource->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY)
mapping = false;
else
mapping = true;
del_device_memory(nid, start_pfn << PAGE_SHIFT, npages << PAGE_SHIFT,
NULL,
mapping);
...
...
In this way, we do not need to play tricks in HMM/devm code, we just need to
call those functions when adding/removing memory.
We would still have to figure out a way to go for the release_mem_region_adjustable() stuff though.
Thanks
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2018-08-08 13:42 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
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 [this message]
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=20180808134233.GA10946@techadventures.net \
--to=osalvador@techadventures.net \
--cc=akpm@linux-foundation.org \
--cc=dan.j.williams@intel.com \
--cc=dave.jiang@intel.com \
--cc=david@redhat.com \
--cc=jglisse@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=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).