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2019-04-04doc/mm: New documentation for memory performanceKeith Busch1-0/+169
Platforms may provide system memory where some physical address ranges perform differently than others, or is cached by the system on the memory side. Add documentation describing a high level overview of such systems and the perforamnce and caching attributes the kernel provides for applications wishing to query this information. Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Tested-by: Brice Goglin <Brice.Goglin@inria.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-06mm: convert PG_balloon to PG_offlineDavid Hildenbrand1-3/+6
PG_balloon was introduced to implement page migration/compaction for pages inflated in virtio-balloon. Nowadays, it is only a marker that a page is part of virtio-balloon and therefore logically offline. We also want to make use of this flag in other balloon drivers - for inflated pages or when onlining a section but keeping some pages offline (e.g. used right now by XEN and Hyper-V via set_online_page_callback()). We are going to expose this flag to dump tools like makedumpfile. But instead of exposing PG_balloon, let's generalize the concept of marking pages as logically offline, so it can be reused for other purposes later on. Rename PG_balloon to PG_offline. This is an indicator that the page is logically offline, the content stale and that it should not be touched (e.g. a hypervisor would have to allocate backing storage in order for the guest to dump an unused page). We can then e.g. exclude such pages from dumps. We replace and reuse KPF_BALLOON (23), as this shouldn't really harm (and for now the semantics stay the same). In following patches, we will make use of this bit also in other balloon drivers. While at it, document PGTABLE. [akpm@linux-foundation.org: fix comment text, per David] Link: http://lkml.kernel.org/r/20181119101616.8901-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Konstantin Khlebnikov <koct9i@gmail.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: David Rientjes <rientjes@google.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Young <dyoung@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kairui Song <kasong@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-20docs/admin-guide/mm/concepts.rst: grammar and style fixupsMike Rapoport1-25/+26
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-31memory-hotplug.rst: add some details about locking internalsDavid Hildenbrand1-1/+41
Let's document the magic a bit, especially why device_hotplug_lock is required when adding/removing memory and how it all play together with requests to online/offline memory from user space. Link: http://lkml.kernel.org/r/20180925091457.28651-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Len Brown <lenb@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-13docs/admin-guide: memory-hotplug: remove table of contentsMike Rapoport1-21/+0
Remove "manual" table of contents and leave only the ReST tag so that Sphinx will take care of TOC generation. Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-07docs/vm: split memory hotplug notifier description to Documentation/core-apiMike Rapoport1-83/+0
The memory hotplug notifier description is about kernel internals rather than admin/user visible API. Place it appropriately. Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-07docs: move memory hotplug description into admin-guide/mmMike Rapoport2-0/+509
The memory hotplug description in Documentation/memory-hotplug.txt is already formatted as ReST and can be easily added to admin-guide/mm section. While on it, slightly update formatting to make it consistent with the doc-guide. Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-18tools/vm/page-types.c: add support for idle page trackingChristian Hansen1-0/+5
Add a flag which causes page-types to use the kernels's idle page tracking to mark pages idle. As the tool already prints the idle flag if set, subsequent runs will show which pages have been accessed since last run. [akpm@linux-foundation.org: simplify mark_page_idle()] [chansen3@cisco.com: reorganize mark_page_idle() logic, add docs] Link: http://lkml.kernel.org/r/20180706172237.21691-1-chansen3@cisco.com Link: http://lkml.kernel.org/r/20180612153223.13174-1-chansen3@cisco.com Signed-off-by: Christian Hansen <chansen3@cisco.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-18tools/vm/page-types.c: include shared map countsChristian Hansen1-0/+3
Add a new flag that will read kpagecount for each PFN and print out the number of times the page is mapped along with the flags in the listing view. This information is useful in understanding and optimizing memory usage. Identifying pages which are not shared allows us to focus on adjusting the memory layout or access patterns for the sole owning process. Knowing the number of processes that share a page tells us how many other times we must make the same adjustments or how many processes to potentially disable. Truncated sample output: voffset map-cnt offset len flags 561a3591e 1 15fe8 1 ___U_lA____Ma_b___________________________ 561a3591f 1 2b103 1 ___U_lA____Ma_b___________________________ 561a36ca4 1 2cc78 1 ___U_lA____Ma_b___________________________ 7f588bb4e 14 2273c 1 __RU_lA____M______________________________ [akpm@linux-foundation.org: coding-style fixes] [chansen3@cisco.com: add documentation, tweak whitespace] Link: http://lkml.kernel.org/r/20180705181204.5529-1-chansen3@cisco.com Link: http://lkml.kernel.org/r/20180612153205.12879-1-chansen3@cisco.com Signed-off-by: Christian Hansen <chansen3@cisco.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-29docs/admin-guide/mm: add high level concepts overviewMike Rapoport2-0/+227
The are terms that seem obvious to the mm developers, but may be somewhat obscure for, say, less involved readers. The concepts overview can be seen as an "extended glossary" that introduces such terms to the readers of the kernel documentation. Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-21docs/vm: transhuge: split userspace bits to admin-guide/mm/transhugeMike Rapoport2-0/+419
Now that the administrative information for transparent huge pages is nicely separated, move it to its own page under the admin guide. Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-08docs/vm: move numa_memory_policy.rst to Documentation/admin-guide/mmMike Rapoport3-1/+497
The document describes userspace API and as such it belongs to Documentation/admin-guide/mm Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-28docs/vm: ksm: split userspace interface to admin-guide/mm/ksm.rstMike Rapoport2-0/+190
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-28docs/admin-guide/mm: convert plain text cross references to hyperlinksMike Rapoport3-10/+16
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-28docs/admin-guide/mm: start moving here files from Documentation/vmMike Rapoport6-0/+990
Several documents in Documentation/vm fit quite well into the "admin/user guide" category. The documents that don't overload the reader with lots of implementation details and provide coherent description of certain feature can be moved to Documentation/admin-guide/mm. Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-28docs/admin-guide: introduce basic index for mm documentationMike Rapoport1-0/+19
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>