From: Oscar Salvador <osalvador@suse.de>
To: Leonardo Bras <leonardo@linux.ibm.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Mike Rapoport" <rppt@linux.ibm.com>,
"Michal Hocko" <mhocko@suse.com>,
"Pavel Tatashin" <pasha.tatashin@oracle.com>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Pasha Tatashin" <Pavel.Tatashin@microsoft.com>,
"Bartlomiej Zolnierkiewicz" <b.zolnierkie@samsung.com>
Subject: Re: [PATCH 1/1] mm/memory_hotplug: Adds option to hot-add memory in ZONE_MOVABLE
Date: Thu, 18 Jul 2019 08:12:33 +0200 [thread overview]
Message-ID: <1563430353.3077.1.camel@suse.de> (raw)
In-Reply-To: <20190718024133.3873-1-leonardo@linux.ibm.com>
On Wed, 2019-07-17 at 23:41 -0300, Leonardo Bras wrote:
> Adds an option on kernel config to make hot-added memory online in
> ZONE_MOVABLE by default.
>
> This would be great in systems with MEMORY_HOTPLUG_DEFAULT_ONLINE=y
> by
> allowing to choose which zone it will be auto-onlined
We do already have "movable_node" boot option, which exactly has that
effect.
Any hotplugged range will be placed in ZONE_MOVABLE.
Why do we need yet another option to achieve the same? Was not that
enough for your case?
>
> Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com>
> ---
> drivers/base/memory.c | 3 +++
> mm/Kconfig | 14 ++++++++++++++
> 2 files changed, 17 insertions(+)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index f180427e48f4..378b585785c1 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -670,6 +670,9 @@ static int init_memory_block(struct memory_block
> **memory,
> mem->state = state;
> start_pfn = section_nr_to_pfn(mem->start_section_nr);
> mem->phys_device = arch_get_memory_phys_device(start_pfn);
> +#ifdef CONFIG_MEMORY_HOTPLUG_MOVABLE
> + mem->online_type = MMOP_ONLINE_MOVABLE;
> +#endif
>
> ret = register_memory(mem);
>
> diff --git a/mm/Kconfig b/mm/Kconfig
> index f0c76ba47695..74e793720f43 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -180,6 +180,20 @@ config MEMORY_HOTREMOVE
> depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE
> depends on MIGRATION
>
> +config MEMORY_HOTPLUG_MOVABLE
> + bool "Enhance the likelihood of hot-remove"
> + depends on MEMORY_HOTREMOVE
> + help
> + This option sets the hot-added memory zone to MOVABLE
> which
> + drastically reduces the chance of a hot-remove to fail due
> to
> + unmovable memory segments. Kernel memory can't be
> allocated in
> + this zone.
> +
> + Say Y here if you want to have better chance to hot-remove
> memory
> + that have been previously hot-added.
> + Say N here if you want to make all hot-added memory
> available to
> + kernel space.
> +
> # Heavily threaded applications may benefit from splitting the mm-
> wide
> # page_table_lock, so that faults on different parts of the user
> address
> # space can be handled with less contention: split it at this
> NR_CPUS.
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2019-07-18 6:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-18 2:41 [PATCH 1/1] mm/memory_hotplug: Adds option to hot-add memory in ZONE_MOVABLE Leonardo Bras
2019-07-18 6:12 ` Oscar Salvador [this message]
2019-07-18 15:50 ` Leonardo Bras
2019-07-18 15:57 ` Michal Hocko
2019-07-18 16:11 ` Pavel Tatashin
2019-07-18 16:40 ` Michal Hocko
2019-07-18 16:43 ` Pavel Tatashin
2019-07-18 6:26 ` Mike Rapoport
2019-07-18 12:19 ` Pavel Tatashin
2019-07-18 16:03 ` Leonardo Bras
2019-07-18 16:45 ` Pavel Tatashin
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