kernel/mm/memory_hotplug.c, branch linux-2.6.23.y

memory hotplug: fix unnecessary calling of init_currenty_empty_zone()

2007-06-01T15:18:29Z

zone->present_pages is updated in online_pages(). But, __add_zone() can be called twice or more before calling online_pages(). So, init_currenty_empty_zone() can be called unnecessary times. It is cause of memory leak of zone's wait_table. Signed-off-by: Yasunori Goto Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Fix sparsemem on Cell

2007-01-12T02:18:20Z

Fix an oops experienced on the Cell architecture when init-time functions, early_*(), are called at runtime. It alters the call paths to make sure that the callers explicitly say whether the call is being made on behalf of a hotplug even, or happening at boot-time. It has been compile tested on ppc64, ia64, s390, i386 and x86_64. Acked-by: Arnd Bergmann Signed-off-by: Dave Hansen Cc: Yasunori Goto Acked-by: Andy Whitcroft Cc: Christoph Lameter Cc: Martin Schwidefsky Acked-by: Heiko Carstens Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Get rid of zone_table[]

2006-12-07T16:39:20Z

The zone table is mostly not needed. If we have a node in the page flags then we can get to the zone via NODE_DATA() which is much more likely to be already in the cpu cache. In case of SMP and UP NODE_DATA() is a constant pointer which allows us to access an exact replica of zonetable in the node_zones field. In all of the above cases there will be no need at all for the zone table. The only remaining case is if in a NUMA system the node numbers do not fit into the page flags. In that case we make sparse generate a table that maps sections to nodes and use that table to to figure out the node number. This table is sized to fit in a single cache line for the known 32 bit NUMA platform which makes it very likely that the information can be obtained without a cache miss. For sparsemem the zone table seems to be have been fairly large based on the maximum possible number of sections and the number of zones per node. There is some memory saving by removing zone_table. The main benefit is to reduce the cache foootprint of the VM from the frequent lookups of zones. Plus it simplifies the page allocator. [akpm@osdl.org: build fix] Signed-off-by: Christoph Lameter Cc: Dave Hansen Cc: Andy Whitcroft Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] hot-add-mem x86_64: use CONFIG_MEMORY_HOTPLUG_RESERVE

2006-10-01T07:39:18Z

The api for hot-add memory already has a construct for finding nodes based on an address, memory_add_physaddr_to_nid. This patch allows the fucntion to do something besides return 0. It uses the nodes_add infomation to lookup to node info for a hot add event. Signed-off-by: Keith Mannthey Cc: KAMEZAWA Hiroyuki Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] hot-add-mem x86_64: use CONFIG_MEMORY_HOTPLUG_SPARSE

2006-10-01T07:39:18Z

Migate CONFIG_MEMORY_HOTPLUG to CONFIG_MEMORY_HOTPLUG_SPARSE where needed. Signed-off-by: Keith Mannthey Cc: KAMEZAWA Hiroyuki Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] hot-add-mem x86_64: fixup externs

2006-10-01T07:39:18Z

Fix up externs in memory_hotplug.c. Cleanup. Signed-off-by: Keith Mannthey Cc: KAMEZAWA Hiroyuki Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] call mm/page-writeback.c:set_ratelimit() when new pages are hot-added

2006-09-29T16:18:22Z

ratelimit_pages in page-writeback.c is recalculated (in set_ratelimit()) every time a CPU is hot-added/removed. But this value is not recalculated when new pages are hot-added. This patch fixes that problem by calling set_ratelimit() when new pages are hot-added. [akpm@osdl.org: cleanups] Signed-off-by: Chandra Seetharaman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] cpuset: top_cpuset tracks hotplug changes to node_online_map

2006-09-29T16:18:21Z

Change the list of memory nodes allowed to tasks in the top (root) nodeset to dynamically track what cpus are online, using a call to a cpuset hook from the memory hotplug code. Make this top cpus file read-only. On systems that have cpusets configured in their kernel, but that aren't actively using cpusets (for some distros, this covers the majority of systems) all tasks end up in the top cpuset. If that system does support memory hotplug, then these tasks cannot make use of memory nodes that are added after system boot, because the memory nodes are not allowed in the top cpuset. This is a surprising regression over earlier kernels that didn't have cpusets enabled. One key motivation for this change is to remain consistent with the behaviour for the top_cpuset's 'cpus', which is also read-only, and which automatically tracks the cpu_online_map. This change also has the minor benefit that it fixes a long standing, little noticed, minor bug in cpusets. The cpuset performance tweak to short circuit the cpuset_zone_allowed() check on systems with just a single cpuset (see 'number_of_cpusets', in linux/cpuset.h) meant that simply changing the 'mems' of the top_cpuset had no affect, even though the change (the write system call) appeared to succeed. With the following change, that write to the 'mems' file fails -EACCES, and the 'mems' file stubbornly refuses to be changed via user space writes. Thus no one should be mislead into thinking they've changed the top_cpusets's 'mems' when in affect they haven't. In order to keep the behaviour of cpusets consistent between systems actively making use of them and systems not using them, this patch changes the behaviour of the 'mems' file in the top (root) cpuset, making it read only, and making it automatically track the value of node_online_map. Thus tasks in the top cpuset will have automatic use of hot plugged memory nodes allowed by their cpuset. [akpm@osdl.org: build fix] [bunk@stusta.de: build fix] Signed-off-by: Paul Jackson Signed-off-by: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] memory hotadd fixes: enhance collision check

2006-08-06T15:57:49Z

This patch is for collision check enhancement for memory hot add. It's better to do resouce collision check before doing memory hot add, which will touch memory management structures. And add_section() should check section exists or not before calling sparse_add_one_section(). (sparse_add_one_section() will do another check anyway. but checking in memory_hotplug.c will be easy to understand.) Signed-off-by: KAMEZAWA Hiroyuki Cc: keith mannthey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] memory hotadd fixes: find_next_system_ram catch range fix

2006-08-06T15:57:48Z

find_next_system_ram() is used to find available memory resource at onlining newly added memory. This patch fixes following problem. find_next_system_ram() cannot catch this case. Resource: (start)-------------(end) Section : (start)-------------(end) Signed-off-by: KAMEZAWA Hiroyuki Cc: Keith Mannthey Cc: Yasunori Goto Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds