From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org, linux-mm@kvack.org,
linux-hyperv@vger.kernel.org, xen-devel@lists.xenproject.org,
linux-acpi@vger.kernel.org, linux-nvdimm@lists.01.org,
linux-s390@vger.kernel.org,
"Andrew Morton" <akpm@linux-foundation.org>,
"David Hildenbrand" <david@redhat.com>,
"Andrew Morton" <akpmt@linux-foundation.org>,
"Anton Blanchard" <anton@ozlabs.org>,
"Ard Biesheuvel" <ardb@kernel.org>, "Baoquan He" <bhe@redhat.com>,
"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"Christian Borntraeger" <borntraeger@de.ibm.com>,
"Eric Biederman" <ebiederm@xmission.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Haiyang Zhang" <haiyangz@microsoft.com>,
"Heiko Carstens" <hca@linux.ibm.com>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Jason Wang" <jasowang@redhat.com>,
"Juergen Gross" <jgross@suse.com>,
"Julien Grall" <julien@xen.org>,
"Kees Cook" <keescook@chromium.org>,
"K. Y. Srinivasan" <kys@microsoft.com>,
"Len Brown" <lenb@kernel.org>
Subject: [PATCH v4 0/8] selective merging of system ram resources
Date: Fri, 11 Sep 2020 12:34:51 +0200 [thread overview]
Message-ID: <20200911103459.10306-1-david@redhat.com> (raw)
Some add_memory*() users add memory in small, contiguous memory blocks.
Examples include virtio-mem, hyper-v balloon, and the XEN balloon.
This can quickly result in a lot of memory resources, whereby the actual
resource boundaries are not of interest (e.g., it might be relevant for
DIMMs, exposed via /proc/iomem to user space). We really want to merge
added resources in this scenario where possible.
Resources are effectively stored in a list-based tree. Having a lot of
resources not only wastes memory, it also makes traversing that tree more
expensive, and makes /proc/iomem explode in size (e.g., requiring
kexec-tools to manually merge resources when creating a kdump header. The
current kexec-tools resource count limit does not allow for more than
~100GB of memory with a memory block size of 128MB on x86-64).
Let's allow to selectively merge system ram resources by specifying a
new flag for add_memory*(). Patch #5 contains a /proc/iomem example. Only
tested with virtio-mem.
v3 -> v4:
- "mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG"
-- Fix configs without CONFIG_MEMORY_HOTPLUG with the new mhp_t type
-- Did a buch of cross-compiles with different configs, hope there isn't
anything I missed.
v2 -> v3:
- "mm/memory_hotplug: prepare passing flags to add_memory() and friends"
-- Use proper __bitwise type for flags
-- Use "MHP_NONE" for empty flags
- Rebased to latest -next, added rb's
v1 -> v2:
- I had another look at v1 after vacation and didn't like it - it felt like
a hack. So I want forward and added a proper flag to add_memory*(), and
introduce a clean (non-racy) way to mark System RAM resources mergeable.
- "kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED"
-- Clean that flag up, felt wrong in the PnP section
- "mm/memory_hotplug: prepare passing flags to add_memory() and friends"
-- Previously sent in other context - decided to keep Wei's ack
- "mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System
RAM resources"
-- Cleaner approach to get the job done by using proper flags and only
merging the single, specified resource
- "virtio-mem: try to merge system ram resources"
"xen/balloon: try to merge system ram resources"
"hv_balloon: try to merge system ram resources"
-- Use the new flag MEMHP_MERGE_RESOURCE, much cleaner
RFC -> v1:
- Switch from rather generic "merge_child_mem_resources()" where a resource
name has to be specified to "merge_system_ram_resources().
- Smaller comment/documentation/patch description changes/fixes
David Hildenbrand (8):
kernel/resource: make release_mem_region_adjustable() never fail
kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED
mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG
mm/memory_hotplug: prepare passing flags to add_memory() and friends
mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System
RAM resources
virtio-mem: try to merge system ram resources
xen/balloon: try to merge system ram resources
hv_balloon: try to merge system ram resources
arch/powerpc/platforms/powernv/memtrace.c | 2 +-
.../platforms/pseries/hotplug-memory.c | 2 +-
drivers/acpi/acpi_memhotplug.c | 3 +-
drivers/base/memory.c | 3 +-
drivers/dax/kmem.c | 2 +-
drivers/hv/hv_balloon.c | 2 +-
drivers/s390/char/sclp_cmd.c | 2 +-
drivers/virtio/virtio_mem.c | 3 +-
drivers/xen/balloon.c | 2 +-
include/linux/ioport.h | 12 +-
include/linux/memory_hotplug.h | 35 +++---
kernel/kexec_file.c | 2 +-
kernel/resource.c | 109 ++++++++++++++----
mm/memory_hotplug.c | 47 +++-----
mm/sparse.c | 2 +
15 files changed, 151 insertions(+), 77 deletions(-)
--
2.26.2
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next reply other threads:[~2020-09-11 10:35 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-11 10:34 David Hildenbrand [this message]
2020-09-11 10:34 ` [PATCH v4 1/8] kernel/resource: make release_mem_region_adjustable() never fail David Hildenbrand
2020-09-22 6:07 ` [PATCH] kernel/resource: Fix use of ternary condition in release_mem_region_adjustable Nathan Chancellor
2020-09-22 6:22 ` David Hildenbrand
2020-10-09 9:24 ` Wei Yang
2020-09-11 10:34 ` [PATCH v4 2/8] kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED David Hildenbrand
2020-09-11 10:34 ` [PATCH v4 3/8] mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG David Hildenbrand
2020-09-11 10:34 ` [PATCH v4 4/8] mm/memory_hotplug: prepare passing flags to add_memory() and friends David Hildenbrand
2020-09-11 10:34 ` [PATCH v4 5/8] mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System RAM resources David Hildenbrand
2020-09-15 2:43 ` Wei Yang
2020-09-15 7:25 ` David Hildenbrand
2020-09-16 12:51 ` Wei Yang
2020-09-11 10:34 ` [PATCH v4 6/8] virtio-mem: try to merge system ram resources David Hildenbrand
2020-09-16 12:52 ` Wei Yang
2020-09-11 10:34 ` [PATCH v4 7/8] xen/balloon: " David Hildenbrand
2020-09-16 12:52 ` Wei Yang
2020-09-11 10:34 ` [PATCH v4 8/8] hv_balloon: " David Hildenbrand
2020-09-16 12:52 ` Wei Yang
2020-09-16 7:30 ` [PATCH] kernel/resource: make iomem_resource implicit in release_mem_region_adjustable() David Hildenbrand
2020-09-16 10:02 ` Wei Yang
2020-09-16 10:03 ` David Hildenbrand
2020-09-16 12:10 ` Wei Yang
2020-09-16 12:16 ` David Hildenbrand
2020-09-16 12:40 ` Wei Yang
2020-09-17 8:38 ` Pankaj Gupta
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