From: "Michael S. Tsirkin" <mst@redhat.com>
To: David Hildenbrand <david@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
virtio-dev@lists.oasis-open.org,
virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
Michal Hocko <mhocko@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>,
Pankaj Gupta <pankaj.gupta.linux@gmail.com>,
Oscar Salvador <osalvador@suse.com>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Wei Yang <richard.weiyang@gmail.com>,
Dan Williams <dan.j.williams@intel.com>, Qian Cai <cai@lca.pw>
Subject: Re: [PATCH v3 07/15] mm/memory_hotplug: Introduce offline_and_remove_memory()
Date: Thu, 7 May 2020 06:46:46 -0400 [thread overview]
Message-ID: <20200507064558-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20200507103119.11219-8-david@redhat.com>
On Thu, May 07, 2020 at 12:31:11PM +0200, David Hildenbrand wrote:
> virtio-mem wants to offline and remove a memory block once it unplugged
> all subblocks (e.g., using alloc_contig_range()). Let's provide
> an interface to do that from a driver. virtio-mem already supports to
> offline partially unplugged memory blocks. Offlining a fully unplugged
> memory block will not require to migrate any pages. All unplugged
> subblocks are PageOffline() and have a reference count of 0 - so
> offlining code will simply skip them.
>
> All we need is an interface to offline and remove the memory from kernel
> module context, where we don't have access to the memory block devices
> (esp. find_memory_block() and device_offline()) and the device hotplug
> lock.
>
> To keep things simple, allow to only work on a single memory block.
>
> Acked-by: Michal Hocko <mhocko@suse.com>
> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Oscar Salvador <osalvador@suse.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
> Cc: Wei Yang <richard.weiyang@gmail.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Qian Cai <cai@lca.pw>
> Signed-off-by: David Hildenbrand <david@redhat.com>
didn't you lose Andrew Morton's ack here?
> ---
> include/linux/memory_hotplug.h | 1 +
> mm/memory_hotplug.c | 37 ++++++++++++++++++++++++++++++++++
> 2 files changed, 38 insertions(+)
I get:
error: sha1 information is lacking or useless (mm/memory_hotplug.c).
error: could not build fake ancestor
which version is this against? Pls post patches on top of some tag
in Linus' tree if possible.
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index 7dca9cd6076b..d641828e5596 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -318,6 +318,7 @@ extern void try_offline_node(int nid);
> extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
> extern int remove_memory(int nid, u64 start, u64 size);
> extern void __remove_memory(int nid, u64 start, u64 size);
> +extern int offline_and_remove_memory(int nid, u64 start, u64 size);
>
> #else
> static inline void try_offline_node(int nid) {}
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 936bfe208a6e..bf1941f02a60 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1748,4 +1748,41 @@ int remove_memory(int nid, u64 start, u64 size)
> return rc;
> }
> EXPORT_SYMBOL_GPL(remove_memory);
> +
> +/*
> + * Try to offline and remove a memory block. Might take a long time to
> + * finish in case memory is still in use. Primarily useful for memory devices
> + * that logically unplugged all memory (so it's no longer in use) and want to
> + * offline + remove the memory block.
> + */
> +int offline_and_remove_memory(int nid, u64 start, u64 size)
> +{
> + struct memory_block *mem;
> + int rc = -EINVAL;
> +
> + if (!IS_ALIGNED(start, memory_block_size_bytes()) ||
> + size != memory_block_size_bytes())
> + return rc;
> +
> + lock_device_hotplug();
> + mem = find_memory_block(__pfn_to_section(PFN_DOWN(start)));
> + if (mem)
> + rc = device_offline(&mem->dev);
> + /* Ignore if the device is already offline. */
> + if (rc > 0)
> + rc = 0;
> +
> + /*
> + * In case we succeeded to offline the memory block, remove it.
> + * This cannot fail as it cannot get onlined in the meantime.
> + */
> + if (!rc) {
> + rc = try_remove_memory(nid, start, size);
> + WARN_ON_ONCE(rc);
> + }
> + unlock_device_hotplug();
> +
> + return rc;
> +}
> +EXPORT_SYMBOL_GPL(offline_and_remove_memory);
> #endif /* CONFIG_MEMORY_HOTREMOVE */
> --
> 2.25.3
next prev parent reply other threads:[~2020-05-07 10:46 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 10:31 [PATCH v3 00/15] virtio-mem: paravirtualized memory David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 01/15] virtio-mem: Paravirtualized memory hotplug David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 02/15] virtio-mem: Allow to specify an ACPI PXM as nid David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 03/15] virtio-mem: Paravirtualized memory hotunplug part 1 David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 04/15] virtio-mem: Paravirtualized memory hotunplug part 2 David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 05/15] mm: Allow to offline unmovable PageOffline() pages via MEM_GOING_OFFLINE David Hildenbrand
2020-05-07 10:48 ` Michael S. Tsirkin
2020-05-07 10:31 ` [PATCH v3 06/15] virtio-mem: Allow to offline partially unplugged memory blocks David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 07/15] mm/memory_hotplug: Introduce offline_and_remove_memory() David Hildenbrand
2020-05-07 10:46 ` Michael S. Tsirkin [this message]
2020-05-07 11:24 ` David Hildenbrand
2020-05-07 11:33 ` David Hildenbrand
2020-05-07 11:34 ` Michael S. Tsirkin
2020-05-07 11:37 ` David Hildenbrand
2020-05-07 12:11 ` Michael S. Tsirkin
2020-05-07 12:24 ` David Hildenbrand
2020-05-07 11:33 ` Michael S. Tsirkin
2020-05-07 10:31 ` [PATCH v3 08/15] virtio-mem: Offline and remove completely unplugged memory blocks David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 09/15] virtio-mem: Better retry handling David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 10/15] MAINTAINERS: Add myself as virtio-mem maintainer David Hildenbrand
2020-05-07 10:47 ` Michael S. Tsirkin
2020-05-07 11:25 ` David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 11/15] virtio-mem: Add parent resource for all added "System RAM" David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 12/15] virtio-mem: Drop manual check for already present memory David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 13/15] virtio-mem: Unplug subblocks right-to-left David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 14/15] virtio-mem: Use -ETXTBSY as error code if the device is busy David Hildenbrand
2020-05-07 10:31 ` [PATCH v3 15/15] virtio-mem: Try to unplug the complete online memory block first David Hildenbrand
2020-05-07 10:48 ` [PATCH v3 00/15] virtio-mem: paravirtualized memory Michael S. Tsirkin
2020-05-07 11:23 ` David Hildenbrand
2020-05-14 6:44 ` [virtio-dev] " teawater
2020-05-14 8:48 ` David Hildenbrand
2020-05-14 10:02 ` teawater
2020-05-14 10:12 ` David Hildenbrand
2020-05-14 11:10 ` David Hildenbrand
2020-05-14 11:47 ` David Hildenbrand
2020-05-14 12:19 ` David Hildenbrand
2020-05-15 2:58 ` teawater
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=20200507064558-mutt-send-email-mst@kernel.org \
--to=mst@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=cai@lca.pw \
--cc=dan.j.williams@intel.com \
--cc=david@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=mhocko@suse.com \
--cc=osalvador@suse.com \
--cc=pankaj.gupta.linux@gmail.com \
--cc=pasha.tatashin@soleen.com \
--cc=richard.weiyang@gmail.com \
--cc=virtio-dev@lists.oasis-open.org \
--cc=virtualization@lists.linux-foundation.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 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).