Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1617766
| From | Michal Hocko <mhocko@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 0/6] mm: make movable onlining suck less |
| Date | 2017-04-06 11:30 +0200 |
| Message-ID | <ttbTQ-6GC-33@gated-at.bofh.it> (permalink) |
| References | (5 earlier) <tsCCK-RD-9@gated-at.bofh.it> <tsEuS-21A-3@gated-at.bofh.it> <tsMVr-7ys-11@gated-at.bofh.it> <tsVvH-4x0-13@gated-at.bofh.it> <tsW8q-51d-17@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed 05-04-17 18:34:39, Michal Hocko wrote: > On Wed 05-04-17 10:48:52, Reza Arbab wrote: > > On Wed, Apr 05, 2017 at 08:42:39AM +0200, Michal Hocko wrote: > > >On Tue 04-04-17 16:43:39, Reza Arbab wrote: > > >>Okay, getting further. With this I can again repeatedly add and remove, > > >>but now I'm seeing a weird variation of that earlier issue: > > >> > > >>1. add_memory(), online_movable > > >> /sys/devices/system/node/nodeX/memoryY symlinks are created. > > >> > > >>2. offline, remove_memory() > > >> The node is offlined, since all memory has been removed, so all of > > >> /sys/devices/system/node/nodeX is gone. This is normal. > > >> > > >>3. add_memory(), online_movable > > >> The node is onlined, so /sys/devices/system/node/nodeX is recreated, > > >> and the memory is added, but just like earlier in this email thread, > > >> the memoryY links are not there. > > > > > >Could you add some printks to see why the sysfs creation failed please? > > > > Ah, simple enough. It's this, right at the top of > > register_mem_sect_under_node(): > > > > if (!node_online(nid)) > > return 0; > > > > That being the case, I really don't understand why your patches make any > > difference. Is node_set_online() being called later than before somehow? > > This is really interesting. Because add_memory_resource does the > following > /* call arch's memory hotadd */ > ret = arch_add_memory(nid, start, size); > > if (ret < 0) > goto error; > > /* we online node here. we can't roll back from here. */ > node_set_online(nid); > > so we are setting the node online _after_ arch_add_memory but the code > which adds those sysfs file is called from > > arch_add_memory > __add_pages > __add_section > register_new_memory > register_mem_sect_under_node > node_online check > > I haven't touched this part. What is the point of this check anyway? We > have already associated all the pages with a node (and with a zone prior > to my patches) so we _know_ how to create those links. The check goes > back to the initial submissions. Gary is not available anymore so we > cannot ask. But I completely fail to see how my changes could have made > any difference. I wasn't able to undestand that from the code so I've just tried to remove the check and it blown up BUG: unable to handle kernel NULL pointer dereference at 0000000000000040 IP: sysfs_create_link_nowarn+0x13/0x32 if (!kobj) parent = sysfs_root_kn; else parent = kobj->sd; ^^^^^^^^^^^^^^^^^^ when creating the link register_mem_sect_under_node: ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, &mem_blk->dev.kobj, kobject_name(&mem_blk->dev.kobj)); which means that node_devices[nid]->dev.kobj is NULL. This happens later in register_one_node->register_node. This really _screems_ for a clean up! -- Michal Hocko SUSE Labs
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
[PATCH 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
Re: [PATCH 1/6] mm: get rid of zone_is_initialized "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-03-31 05:50 +0200
Re: [PATCH 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-03-31 08:50 +0200
Re: [PATCH 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-03-31 08:50 +0200
[PATCH v1 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-03-31 09:50 +0200
Re: [PATCH v1 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-04-05 10:20 +0200
Re: [PATCH v1 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-04-05 11:30 +0200
Re: [PATCH v1 1/6] mm: get rid of zone_is_initialized Igor Mammedov <imammedo@redhat.com> - 2017-04-05 11:50 +0200
[PATCH 2/6] mm, tile: drop arch_{add,remove}_memory Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
[PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-03-31 06:00 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-03-31 08:50 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-03-31 09:10 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-03-31 09:20 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-03-31 09:50 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-03 23:30 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-04-04 09:40 +0200
[PATCH 6/6] mm, memory_hotplug: remove unused cruft after memory hotplug rework Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
Re: [PATCH 6/6] mm, memory_hotplug: remove unused cruft after memory hotplug rework Michal Hocko <mhocko@kernel.org> - 2017-03-31 09:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Heiko Carstens <heiko.carstens@de.ibm.com> - 2017-03-31 21:20 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-03 09:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-03 14:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Igor Mammedov <imammedo@redhat.com> - 2017-04-03 14:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-03 22:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-03 22:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-03 22:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 09:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 09:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 10:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-04 18:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-04 18:10 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 18:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-04 20:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 21:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-04 23:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 08:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 11:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 17:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 17:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 19:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 20:20 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 21:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 23:10 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 13:10 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 18:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 18:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 23:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 11:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 16:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 17:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 08:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 15:10 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-06 17:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-06 17:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 18:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Mel Gorman <mgorman@suse.de> - 2017-04-06 18:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Mel Gorman <mgorman@suse.de> - 2017-04-06 19:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 19:20 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Mel Gorman <mgorman@suse.de> - 2017-04-06 19:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 17:50 +0200
csiph-web