From: Michal Hocko <mhocko@suse.com>
To: Oscar Salvador <osalvador@suse.de>
Cc: Laurent Dufour <ldufour@linux.ibm.com>,
akpm@linux-foundation.org, David Hildenbrand <david@redhat.com>,
rafael@kernel.org, nathanl@linux.ibm.com, cheloha@linux.ibm.com,
stable@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: don't rely on system state to detect hot-plug operations
Date: Thu, 10 Sep 2020 14:47:55 +0200 [thread overview]
Message-ID: <20200910124755.GG28354@dhcp22.suse.cz> (raw)
In-Reply-To: <20200910120343.GA6635@linux>
On Thu 10-09-20 14:03:48, Oscar Salvador wrote:
> On Thu, Sep 10, 2020 at 01:35:32PM +0200, Laurent Dufour wrote:
>
> > That points has been raised by David, quoting him here:
> >
> > > IIRC, ACPI can hotadd memory while SCHEDULING, this patch would break that.
> > >
> > > Ccing Oscar, I think he mentioned recently that this is the case with ACPI.
> >
> > Oscar told that he need to investigate further on that.
>
> I think my reply got lost.
>
> We can see acpi hotplugs during SYSTEM_SCHEDULING:
>
> $QEMU -enable-kvm -machine pc -smp 4,sockets=4,cores=1,threads=1 -cpu host -monitor pty \
> -m size=$MEM,slots=255,maxmem=4294967296k \
> -numa node,nodeid=0,cpus=0-3,mem=512 -numa node,nodeid=1,mem=512 \
> -object memory-backend-ram,id=memdimm0,size=134217728 -device pc-dimm,node=0,memdev=memdimm0,id=dimm0,slot=0 \
> -object memory-backend-ram,id=memdimm1,size=134217728 -device pc-dimm,node=0,memdev=memdimm1,id=dimm1,slot=1 \
> -object memory-backend-ram,id=memdimm2,size=134217728 -device pc-dimm,node=0,memdev=memdimm2,id=dimm2,slot=2 \
> -object memory-backend-ram,id=memdimm3,size=134217728 -device pc-dimm,node=0,memdev=memdimm3,id=dimm3,slot=3 \
> -object memory-backend-ram,id=memdimm4,size=134217728 -device pc-dimm,node=1,memdev=memdimm4,id=dimm4,slot=4 \
> -object memory-backend-ram,id=memdimm5,size=134217728 -device pc-dimm,node=1,memdev=memdimm5,id=dimm5,slot=5 \
> -object memory-backend-ram,id=memdimm6,size=134217728 -device pc-dimm,node=1,memdev=memdimm6,id=dimm6,slot=6 \
>
> kernel: [ 0.753643] __add_memory: nid: 0 start: 0100000000 - 0108000000 (size: 134217728)
> kernel: [ 0.756950] register_mem_sect_under_node: system_state= 1
>
> kernel: [ 0.760811] register_mem_sect_under_node+0x4f/0x230
> kernel: [ 0.760811] walk_memory_blocks+0x80/0xc0
> kernel: [ 0.760811] link_mem_sections+0x32/0x40
> kernel: [ 0.760811] add_memory_resource+0x148/0x250
> kernel: [ 0.760811] __add_memory+0x5b/0x90
> kernel: [ 0.760811] acpi_memory_device_add+0x130/0x300
> kernel: [ 0.760811] acpi_bus_attach+0x13c/0x1c0
> kernel: [ 0.760811] acpi_bus_attach+0x60/0x1c0
> kernel: [ 0.760811] acpi_bus_scan+0x33/0x70
> kernel: [ 0.760811] acpi_scan_init+0xea/0x21b
> kernel: [ 0.760811] acpi_init+0x2f1/0x33c
> kernel: [ 0.760811] do_one_initcall+0x46/0x1f4
Is there any actual usecase for a configuration like this? What is the
point to statically define additional memory like this when the same can
be achieved on the same command line?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-09-10 21:49 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5cbd92e1-c00a-4253-0119-c872bfa0f2bc@redhat.com>
2020-09-08 17:08 ` [PATCH] mm: don't rely on system state to detect hot-plug operations Laurent Dufour
2020-09-08 17:31 ` Greg Kroah-Hartman
2020-09-08 17:40 ` David Hildenbrand
2020-09-09 8:26 ` Laurent Dufour
2020-09-09 8:31 ` David Hildenbrand
2020-09-09 9:35 ` Laurent Dufour
2020-09-09 6:56 ` Laurent Dufour
2020-09-09 7:40 ` Michal Hocko
2020-09-09 7:48 ` Laurent Dufour
2020-09-09 9:09 ` Michal Hocko
2020-09-09 9:21 ` Laurent Dufour
2020-09-09 9:24 ` David Hildenbrand
2020-09-09 9:32 ` Laurent Dufour
2020-09-09 12:30 ` Greg Kroah-Hartman
2020-09-09 12:32 ` David Hildenbrand
2020-09-09 12:36 ` Greg Kroah-Hartman
2020-09-09 12:45 ` Michal Hocko
2020-09-09 10:59 ` Michal Hocko
2020-09-09 16:07 ` Laurent Dufour
2020-09-10 7:23 ` Michal Hocko
2020-09-10 7:51 ` Laurent Dufour
2020-09-10 11:12 ` Michal Hocko
2020-09-10 11:35 ` Laurent Dufour
2020-09-10 12:00 ` David Hildenbrand
2020-09-10 12:36 ` Laurent Dufour
2020-09-10 12:38 ` David Hildenbrand
2020-09-10 12:01 ` Michal Hocko
2020-09-10 12:03 ` Oscar Salvador
2020-09-10 12:32 ` Laurent Dufour
2020-09-10 12:47 ` Michal Hocko [this message]
2020-09-10 12:48 ` Michal Hocko
2020-09-10 13:39 ` Oscar Salvador
2020-09-10 13:51 ` Michal Hocko
2020-09-10 14:40 ` Michal Hocko
2020-09-10 12:49 ` David Hildenbrand
2020-09-10 13:54 ` Michal Hocko
2020-09-10 13:57 ` David Hildenbrand
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=20200910124755.GG28354@dhcp22.suse.cz \
--to=mhocko@suse.com \
--cc=akpm@linux-foundation.org \
--cc=cheloha@linux.ibm.com \
--cc=david@redhat.com \
--cc=gregkh@linuxfoundation.org \
--cc=ldufour@linux.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=nathanl@linux.ibm.com \
--cc=osalvador@suse.de \
--cc=rafael@kernel.org \
--cc=stable@vger.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.