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* [PATCH] NUMA aware block device control structure allocationChristoph Lameter2005-06-23
| | | | | | | | | | | | | | | | Patch to allocate the control structures for for ide devices on the node of the device itself (for NUMA systems). The patch depends on the Slab API change patch by Manfred and me (in mm) and the pcidev_to_node patch that I posted today. Does some realignment too. Signed-off-by: Justin M. Forbes <jmforbes@linuxtx.org> Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Pravin Shelar <pravin@calsoftinc.com> Signed-off-by: Shobhit Dayal <shobhit@calsoftinc.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem hotplug baseAndy Whitcroft2005-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sparse's initalization be accessible at runtime. This allows sparse mappings to be created after boot in a hotplug situation. This patch is separated from the previous one just to give an indication how much of the sparse infrastructure is *just* for hotplug memory. The section_mem_map doesn't really store a pointer. It stores something that is convenient to do some math against to get a pointer. It isn't valid to just do *section_mem_map, so I don't think it should be stored as a pointer. There are a couple of things I'd like to store about a section. First of all, the fact that it is !NULL does not mean that it is present. There could be such a combination where section_mem_map *is* NULL, but the math gets you properly to a real mem_map. So, I don't think that check is safe. Since we're storing 32-bit-aligned structures, we have a few bits in the bottom of the pointer to play with. Use one bit to encode whether there's really a mem_map there, and the other one to tell whether there's a valid section there. We need to distinguish between the two because sometimes there's a gap between when a section is discovered to be present and when we can get the mem_map for it. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem swiss cheese numa layoutsAndy Whitcroft2005-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The part of the sparsemem patch which modifies memmap_init_zone() has recently become a problem. It changes behavior so that there is a call to pfn_to_page() for each individual page inside of a node's range: node_start_pfn through node_end_pfn. It used to simply do this once, at the beginning of the node, but having sparsemem's non-contiguous mem_map[]s inside of a node made it necessary to change. Mike Kravetz recently wrote a patch which made the NUMA code accept some new kinds of layouts. The system's memory was laid out like this, with node 0's memory in two pieces: one before and one after node 1's memory: Node 0: +++++ +++++ Node 1: +++++ Previous behavior before Mike's patch was to assign nodes like this: Node 0: 00000 XXXXX Node 1: 11111 Where the 'X' areas were simply thrown away. The new behavior was to make the pg_data_t span node 0 across all of its areas, including areas that are really node 1's: Node 0: 000000000000000 Node 1: 11111 This wastes a little bit of mem_map space, but ends up being OK, and more fully utilizes the system's memory. memmap_init_zone() initializes all of the "struct page"s for node 0, even for the "hole", but those never get used, because there is no pfn_to_page() that resolves to those pages. However, only calling pfn_to_page() once, memmap_init_zone() always uses the pages that were allocated for node0->node_mem_map because: struct page *start = pfn_to_page(start_pfn); // effectively start = &node->node_mem_map[0] for (page = start; page < (start + size); page++) { init_page_here();... page++; } Slow, and wasteful, but generally harmless. But, modify that to call pfn_to_page() for each loop iteration (like sparsemem does): for (pfn = start_pfn; pfn < < (start_pfn + size); pfn++++) { page = pfn_to_page(pfn); } And you end up trying to initialize node 1's pages too early, along with bogus data from node 0. This patch checks for those weird layouts and declines to touch the pages, making the more frequent pfn_to_page() calls OK to do. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem memory modelAndy Whitcroft2005-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparsemem abstracts the use of discontiguous mem_maps[]. This kind of mem_map[] is needed by discontiguous memory machines (like in the old CONFIG_DISCONTIGMEM case) as well as memory hotplug systems. Sparsemem replaces DISCONTIGMEM when enabled, and it is hoped that it can eventually become a complete replacement. A significant advantage over DISCONTIGMEM is that it's completely separated from CONFIG_NUMA. When producing this patch, it became apparent in that NUMA and DISCONTIG are often confused. Another advantage is that sparse doesn't require each NUMA node's ranges to be contiguous. It can handle overlapping ranges between nodes with no problems, where DISCONTIGMEM currently throws away that memory. Sparsemem uses an array to provide different pfn_to_page() translations for each SECTION_SIZE area of physical memory. This is what allows the mem_map[] to be chopped up. In order to do quick pfn_to_page() operations, the section number of the page is encoded in page->flags. Part of the sparsemem infrastructure enables sharing of these bits more dynamically (at compile-time) between the page_zone() and sparsemem operations. However, on 32-bit architectures, the number of bits is quite limited, and may require growing the size of the page->flags type in certain conditions. Several things might force this to occur: a decrease in the SECTION_SIZE (if you want to hotplug smaller areas of memory), an increase in the physical address space, or an increase in the number of used page->flags. One thing to note is that, once sparsemem is present, the NUMA node information no longer needs to be stored in the page->flags. It might provide speed increases on certain platforms and will be stored there if there is room. But, if out of room, an alternate (theoretically slower) mechanism is used. This patch introduces CONFIG_FLATMEM. It is used in almost all cases where there used to be an #ifndef DISCONTIG, because SPARSEMEM and DISCONTIGMEM often have to compile out the same areas of code. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Martin Bligh <mbligh@aracnet.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] generify memory presentAndy Whitcroft2005-06-23
| | | | | | | | | | | | Allow architectures to indicate that they will be providing hooks to indice installed memory areas, memory_present(). Provide prototypes for the i386 implementation. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Martin Bligh <mbligh@aracnet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/Kconfig: give DISCONTIG more help textDave Hansen2005-06-23
| | | | | | | | | This gives DISCONTIGMEM a bit more help text to explain what it does, not just when to choose it. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/Kconfig: hide "Memory Model" selection menuDave Hansen2005-06-23
| | | | | | | | | | | | | I got some feedback from users who think that the new "Memory Model" menu is a little invasive. This patch will hide that menu, except when CONFIG_EXPERIMENTAL is enabled *or* when an individual architecture wants it. An individual arch may want to enable it because they've removed their arch-specific DISCONTIG prompt in favor of the mm/Kconfig one. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem: fix minor "defaults" issue in mm/KconfigDave Hansen2005-06-23
| | | | | | | | | | | | The following patch applies on top of 2.6.12-rc2-mm1. It fixes a minor user interaction issue, and an early reference to SPARSEMEM. This "choice" menu would always default to FLATMEM, as it was listed first. Move it to the end so that the other defaults have a chance first. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Introduce new Kconfig option for NUMA or DISCONTIGDave Hansen2005-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There is some confusion that arose when working on SPARSEMEM patch between what is needed for DISCONTIG vs. NUMA. Multiple pg_data_t's are needed for DISCONTIGMEM or NUMA, independently. All of the current NUMA implementations require an implementation of DISCONTIG. Because of this, quite a lot of code which is really needed for NUMA is actually under DISCONTIG #ifdefs. For SPARSEMEM, we changed some of these #ifdefs to CONFIG_NUMA, but that broke the DISCONTIG=y and NUMA=n case. Introducing this new NEED_MULTIPLE_NODES config option allows code that is needed for both NUMA or DISCONTIG to be separated out from code that is specific to DISCONTIG. One great advantage of this approach is that it doesn't require every architecture to be converted over. All of the current implementations should "just work", only the ones implementing SPARSEMEM will have to be fixed up. The change to free_area_init() makes it work inside, or out of the new config option. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] create mm/Kconfig for arch-independent memory optionsDave Hansen2005-06-23
| | | | | | | | | | | | | | | | | | | | With sparsemem being introduced, we need a central place for new memory-related .config options: mm/Kconfig. This allows us to remove many of the duplicated arch-specific options. The new option, CONFIG_FLATMEM, is there to enable us to detangle NUMA and DISCONTIGMEM. This is a requirement for sparsemem because sparsemem uses the NUMA code without the presence of DISCONTIGMEM. The sparsemem patches use CONFIG_FLATMEM in generic code, so this patch is a requirement before applying them. Almost all places that used to do '#ifndef CONFIG_DISCONTIGMEM' should use '#ifdef CONFIG_FLATMEM' instead. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem base: reorganize page->flags bit operationsDave Hansen2005-06-23
| | | | | | | | | | | | Generify the value fields in the page_flags. The aim is to allow the location and size of these fields to be varied. Additionally we want to move away from fixed allocations per field whilst still enforcing the overall bit utilisation limits. We rely on the compiler to spot and optimise the accessor functions. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sparsemem base: simple NUMA remap space allocatorDave Hansen2005-06-23
| | | | | | | | | | | | | | | | | | | Introduce a simple allocator for the NUMA remap space. This space is very scarce, used for structures which are best allocated node local. This mechanism is also used on non-NUMA ia64 systems with a vmem_map to keep the pgdat->node_mem_map initialized in a consistent place for all architectures. Issues: o alloc_remap takes a node_id where we might expect a pgdat which was intended to allow us to allocate the pgdat's using this mechanism; which we do not yet do. Could have alloc_remap_node() and alloc_remap_nid() for this purpose. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] boot_pageset must not be freed.Christoph Lameter2005-06-22
| | | | | | | | | | The boot_pageset needs to be preserved for hotplugging and for off line processors and nodes. Otherwise pointers will point into memory that has now a different use. /proc/zoneinfo is currently showing strange results if processors / nodes are not present. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kill stray newlineDenis Vlasenko2005-06-21
| | | | | | | OOM killer prints a stray newline. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] msync: check pte dirty earlierAbhijit Karmarkar2005-06-21
| | | | | | | | | | | | | | | | | | | | It's common practice to msync a large address range regularly, in which often only a few ptes have actually been dirtied since the previous pass. sync_pte_range then goes much faster if it tests whether pte is dirty before locating and accessing each struct page cacheline; and it is hardly slowed by ptep_clear_flush_dirty repeating that test in the opposite case, when every pte actually is dirty. But beware, s390's pte_dirty always says false, since its dirty bit is kept in the storage key, located via the struct page address. So skip this optimization in its case: use a pte_maybe_dirty macro which just says true if page_test_and_clear_dirty is implemented. Signed-off-by: Abhijit Karmarkar <abhijitk@veritas.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] can_share_swap_page: use page_mapcountHugh Dickins2005-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | Remember that ironic get_user_pages race? when the raised page_count on a page swapped out led do_wp_page to decide that it had to copy on write, so substituted a different page into userspace. 2.6.7 onwards have Andrea's solution, where try_to_unmap_one backs out if it finds page_count raised. Which works, but is unsatisfying (rmap.c has no other page_count heuristics), and was found a few months ago to hang an intensive page migration test. A year ago I was hesitant to engage page_mapcount, now it seems the right fix. So remove the page_count hack from try_to_unmap_one; and use activate_page in unuse_mm when dropping lock, to replace its secondary effect of helping swapoff to make progress in that case. Simplify can_share_swap_page (now called only on anonymous pages) to check page_mapcount + page_swapcount == 1: still needs the page lock to stabilize their (pessimistic) sum, but does not need swapper_space.tree_lock for that. In do_swap_page, move swap_free and unlock_page below page_add_anon_rmap, to keep sum on the high side, and correct when can_share_swap_page called. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] do_wp_page: cannot share file pageHugh Dickins2005-06-21
| | | | | | | | | | | | | | | A small optimization to do_wp_page's check for whether to avoid copy by reusing the page already mapped. It can never share a cached file page, nor can it share a reserved page (often the empty zero page), so it's a waste of time to lock and unlock in those cases. Which nowadays can both be neatly excluded by a preliminary PageAnon test. Christoph has reported that a preliminary page_count test proved valuable for scalability here, but PageAnon covers more common cases all at once. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] get_user_pages: kill get_page_mapHugh Dickins2005-06-21
| | | | | | | | | | | | | | Since its birth, get_user_pages has been calling a misguided get_page_map function. follow_page has already returned NULL if the pfn is invalid, we cannot reach an invalid pfn from a validated struct page. Remove get_page_map, and the messy rewind in get_user_pages to cope with its failure. Oh, and could we please call that "struct page *page" like everywhere else, instead of "struct page *map"? Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] bad_page: clear reclaim and slabHugh Dickins2005-06-21
| | | | | | | | | | Since free_pages_check complains if PG_reclaim or PG_slab is set, bad_page ought to clear them to avoid repetitive reports (Nikita noticed this too). Let prep_new_page check page_count and PG_slab as free_pages_check does. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mbind: check_range use standard ptwalkHugh Dickins2005-06-21
| | | | | | | | | | | | | Strict mbind's check for currently mapped pages being on node has been using a slow loop which re-evaluates pgd, pud, pmd, pte for each entry: replace that by a standard four-level page table walk like others in mm. Since mmap_sem is held for writing, page_table_lock can be taken at the inner level to limit latency. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mbind: fix verify_pages pte_pageHugh Dickins2005-06-21
| | | | | | | | | | | | Strict mbind's check that pages already mapped are on right node has been using pte_page without checking if pfn_valid, and without page_table_lock to prevent spurious failures when try_to_unmap_one intervenes between the pte_present and the pte_page. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] shmem: restore superblock infoHugh Dickins2005-06-21
| | | | | | | | | | | | | | | | | | | | | | To improve shmem scalability, we allowed tmpfs instances which don't need their blocks or inodes limited not to count them, and not to allocate any sbinfo. Which was okay when the only use for the sbinfo was accounting blocks and inodes; but since then a couple of unrelated projects extending tmpfs want to store other data in the sbinfo. Whether either extension reaches mainline is beside the point: I'm guilty of a bad design decision, and should restore sbinfo to make any such future extensions easier. So, once again allocate a shmem_sb_info for every shmem/tmpfs instance, and now let max_blocks 0 indicate unlimited blocks, and max_inodes 0 unlimited inodes. Brent Casavant verified (many months ago) that this does not perceptibly impact the scalability (since the unlimited sbinfo cacheline is repeatedly accessed but only once dirtied). And merge shmem_set_size into its sole caller shmem_remount_fs. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Reduce size of huge boot per_cpu_pagesetChristoph Lameter2005-06-21
| | | | | | | | | | | | | | | | | | | | | Reduce size of the huge per_cpu_pageset structure in __initdata introduced into mm1 with the pageset localization patchset. Use one specially configured pageset per cpu for all zones and nodes during bootup. - Avoid duplication of pageset initialization code. - do the adding to the pageset list before potential free_pages_bulk in free_hot_cold_page (otherwise we would have to hold a page in a pageset during the period that the boot pagesets are in use). - remove mistaken __cpuinitdata attribute and revert back to __initdata for the boot pageset. A boot pageset is not necessary for cpu hotplug. Tested for UP SMP NUMA on x86_64 (2.6.12-rc6-mm1): UP SMP NUMA Tested on IA64 (2.6.12-rc5-mm2): NUMA (2.6.12-rc6-mm1 broken for IA64 because of sparsemem patches) Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Periodically drain non local pagesetsChristoph Lameter2005-06-21
| | | | | | | | | | | | | | | | | | | | | | | The pageset array can potentially acquire a huge amount of memory on large NUMA systems. F.e. on a system with 512 processors and 256 nodes there will be 256*512 pagesets. If each pageset only holds 5 pages then we are talking about 655360 pages.With a 16K page size on IA64 this results in potentially 10 Gigabytes of memory being trapped in pagesets. The typical cases are much less for smaller systems but there is still the potential of memory being trapped in off node pagesets. Off node memory may be rarely used if local memory is available and so we may potentially have memory in seldom used pagesets without this patch. The slab allocator flushes its per cpu caches every 2 seconds. The following patch flushes the off node pageset caches in the same way by tying into the slab flush. The patch also changes /proc/zoneinfo to include the number of pages currently in each pageset. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add OOM debugJanet Morgan2005-06-21
| | | | | | | | | | | | This patch provides more debug info when the system is OOM. It displays memory stats (basically sysrq-m info) from __alloc_pages() when page allocation fails and during OOM kill. Thanks to Dave Jones for coming up with the idea. Signed-off-by: Janet Morgan <janetmor@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] __read_page_state(): pass unsigned long instead of unsignedBenjamin LaHaise2005-06-21
| | | | | | | | | | By making the offset argument of __read_page_state an unsigned long instead of unsigned, we can avoid forcing the compiler to sign extend a usually constant argument. This saves 1 instruction on x86-64. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] __mod_page_state(): pass unsigned long instead of unsignedBenjamin LaHaise2005-06-21
| | | | | | | | | | By making the offset argument of __mod_page_state an unsigned long instead of unsigned, we can avoid forcing the compiler to sign extend a usually constant argument. This saves 1 instruction on x86-64. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] vm: try_to_free_pages unused argumentDarren Hart2005-06-21
| | | | | | | | | | try_to_free_pages accepts a third argument, order, but hasn't used it since before 2.6.0. The following patch removes the argument and updates all the calls to try_to_free_pages. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mmap topdown fix for large stack limit, large allocationChris Wright2005-06-21
| | | | | | | | | | | | | | The topdown changes in 2.6.12-rc1 can cause large allocations with large stack limit to fail, despite there being space available. The mmap_base-len is only valid when len >= mmap_base. However, nothing in topdown allocator checks this. It's only (now) caught at higher level, which will cause allocation to simply fail. The following change restores the fallback to bottom-up path, which will allow large allocations with large stack limit to potentially still succeed. Signed-off-by: Chris Wright <chrisw@osdl.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Avoiding mmap fragmentationWolfgang Wander2005-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ingo recently introduced a great speedup for allocating new mmaps using the free_area_cache pointer which boosts the specweb SSL benchmark by 4-5% and causes huge performance increases in thread creation. The downside of this patch is that it does lead to fragmentation in the mmap-ed areas (visible via /proc/self/maps), such that some applications that work fine under 2.4 kernels quickly run out of memory on any 2.6 kernel. The problem is twofold: 1) the free_area_cache is used to continue a search for memory where the last search ended. Before the change new areas were always searched from the base address on. So now new small areas are cluttering holes of all sizes throughout the whole mmap-able region whereas before small holes tended to close holes near the base leaving holes far from the base large and available for larger requests. 2) the free_area_cache also is set to the location of the last munmap-ed area so in scenarios where we allocate e.g. five regions of 1K each, then free regions 4 2 3 in this order the next request for 1K will be placed in the position of the old region 3, whereas before we appended it to the still active region 1, placing it at the location of the old region 2. Before we had 1 free region of 2K, now we only get two free regions of 1K -> fragmentation. The patch addresses thes issues by introducing yet another cache descriptor cached_hole_size that contains the largest known hole size below the current free_area_cache. If a new request comes in the size is compared against the cached_hole_size and if the request can be filled with a hole below free_area_cache the search is started from the base instead. The results look promising: Whereas 2.6.12-rc4 fragments quickly and my (earlier posted) leakme.c test program terminates after 50000+ iterations with 96 distinct and fragmented maps in /proc/self/maps it performs nicely (as expected) with thread creation, Ingo's test_str02 with 20000 threads requires 0.7s system time. Taking out Ingo's patch (un-patch available per request) by basically deleting all mentions of free_area_cache from the kernel and starting the search for new memory always at the respective bases we observe: leakme terminates successfully with 11 distinctive hardly fragmented areas in /proc/self/maps but thread creating is gringdingly slow: 30+s(!) system time for Ingo's test_str02 with 20000 threads. Now - drumroll ;-) the appended patch works fine with leakme: it ends with only 7 distinct areas in /proc/self/maps and also thread creation seems sufficiently fast with 0.71s for 20000 threads. Signed-off-by: Wolfgang Wander <wwc@rentec.com> Credit-to: "Richard Purdie" <rpurdie@rpsys.net> Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> (partly) Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] node local per-cpu-pagesChristoph Lameter2005-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch modifies the way pagesets in struct zone are managed. Each zone has a per-cpu array of pagesets. So any particular CPU has some memory in each zone structure which belongs to itself. Even if that CPU is not local to that zone. So the patch relocates the pagesets for each cpu to the node that is nearest to the cpu instead of allocating the pagesets in the (possibly remote) target zone. This means that the operations to manage pages on remote zone can be done with information available locally. We play a macro trick so that non-NUMA pmachines avoid the additional pointer chase on the page allocator fastpath. AIM7 benchmark on a 32 CPU SGI Altix w/o patches: Tasks jobs/min jti jobs/min/task real cpu 1 484.68 100 484.6769 12.01 1.97 Fri Mar 25 11:01:42 2005 100 27140.46 89 271.4046 21.44 148.71 Fri Mar 25 11:02:04 2005 200 30792.02 82 153.9601 37.80 296.72 Fri Mar 25 11:02:42 2005 300 32209.27 81 107.3642 54.21 451.34 Fri Mar 25 11:03:37 2005 400 34962.83 78 87.4071 66.59 588.97 Fri Mar 25 11:04:44 2005 500 31676.92 75 63.3538 91.87 742.71 Fri Mar 25 11:06:16 2005 600 36032.69 73 60.0545 96.91 885.44 Fri Mar 25 11:07:54 2005 700 35540.43 77 50.7720 114.63 1024.28 Fri Mar 25 11:09:49 2005 800 33906.70 74 42.3834 137.32 1181.65 Fri Mar 25 11:12:06 2005 900 34120.67 73 37.9119 153.51 1325.26 Fri Mar 25 11:14:41 2005 1000 34802.37 74 34.8024 167.23 1465.26 Fri Mar 25 11:17:28 2005 with slab API changes and pageset patch: Tasks jobs/min jti jobs/min/task real cpu 1 485.00 100 485.0000 12.00 1.96 Fri Mar 25 11:46:18 2005 100 28000.96 89 280.0096 20.79 150.45 Fri Mar 25 11:46:39 2005 200 32285.80 79 161.4290 36.05 293.37 Fri Mar 25 11:47:16 2005 300 40424.15 84 134.7472 43.19 438.42 Fri Mar 25 11:47:59 2005 400 39155.01 79 97.8875 59.46 590.05 Fri Mar 25 11:48:59 2005 500 37881.25 82 75.7625 76.82 730.19 Fri Mar 25 11:50:16 2005 600 39083.14 78 65.1386 89.35 872.79 Fri Mar 25 11:51:46 2005 700 38627.83 77 55.1826 105.47 1022.46 Fri Mar 25 11:53:32 2005 800 39631.94 78 49.5399 117.48 1169.94 Fri Mar 25 11:55:30 2005 900 36903.70 79 41.0041 141.94 1310.78 Fri Mar 25 11:57:53 2005 1000 36201.23 77 36.2012 160.77 1458.31 Fri Mar 25 12:00:34 2005 Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Shobhit Dayal <shobhit@calsoftinc.com> Signed-off-by: Shai Fultheim <Shai@Scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Hugepage consolidationDavid Gibson2005-06-21
| | | | | | | | | | | | | | | | | | | | A lot of the code in arch/*/mm/hugetlbpage.c is quite similar. This patch attempts to consolidate a lot of the code across the arch's, putting the combined version in mm/hugetlb.c. There are a couple of uglyish hacks in order to covert all the hugepage archs, but the result is a very large reduction in the total amount of code. It also means things like hugepage lazy allocation could be implemented in one place, instead of six. Tested, at least a little, on ppc64, i386 and x86_64. Notes: - this patch changes the meaning of set_huge_pte() to be more analagous to set_pte() - does SH4 need s special huge_ptep_get_and_clear()?? Acked-by: William Lee Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VM: rate limit early reclaimMartin Hicks2005-06-21
| | | | | | | | | | | When early zone reclaim is turned on the LRU is scanned more frequently when a zone is low on memory. This limits when the zone reclaim can be called by skipping the scan if another thread (either via kswapd or sync reclaim) is already reclaiming from the zone. Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VM: add __GFP_NORECLAIMMartin Hicks2005-06-21
| | | | | | | | | | | | | | When using the early zone reclaim, it was noticed that allocating new pages that should be spread across the whole system caused eviction of local pages. This adds a new GFP flag to prevent early reclaim from happening during certain allocation attempts. The example that is implemented here is for page cache pages. We want page cache pages to be spread across the whole system, and we don't want page cache pages to evict other pages to get local memory. Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VM: early zone reclaimMartin Hicks2005-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the core of the (much simplified) early reclaim. The goal of this patch is to reclaim some easily-freed pages from a zone before falling back onto another zone. One of the major uses of this is NUMA machines. With the default allocator behavior the allocator would look for memory in another zone, which might be off-node, before trying to reclaim from the current zone. This adds a zone tuneable to enable early zone reclaim. It is selected on a per-zone basis and is turned on/off via syscall. Adding some extra throttling on the reclaim was also required (patch 4/4). Without the machine would grind to a crawl when doing a "make -j" kernel build. Even with this patch the System Time is higher on average, but it seems tolerable. Here are some numbers for kernbench runs on a 2-node, 4cpu, 8Gig RAM Altix in the "make -j" run: wall user sys %cpu ctx sw. sleeps ---- ---- --- ---- ------ ------ No patch 1009 1384 847 258 298170 504402 w/patch, no reclaim 880 1376 667 288 254064 396745 w/patch & reclaim 1079 1385 926 252 291625 548873 These numbers are the average of 2 runs of 3 "make -j" runs done right after system boot. Run-to-run variability for "make -j" is huge, so these numbers aren't terribly useful except to seee that with reclaim the benchmark still finishes in a reasonable amount of time. I also looked at the NUMA hit/miss stats for the "make -j" runs and the reclaim doesn't make any difference when the machine is thrashing away. Doing a "make -j8" on a single node that is filled with page cache pages takes 700 seconds with reclaim turned on and 735 seconds without reclaim (due to remote memory accesses). The simple zone_reclaim syscall program is at http://www.bork.org/~mort/sgi/zone_reclaim.c Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VM: add may_swap flag to scan_controlMartin Hicks2005-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here's the next round of these patches. These are totally different in an attempt to meet the "simpler" request after the last patches. For reference the earlier threads are: http://marc.theaimsgroup.com/?l=linux-kernel&m=110839604924587&w=2 http://marc.theaimsgroup.com/?l=linux-mm&m=111461480721249&w=2 This set of patches replaces my other vm- patches that are currently in -mm. So they're against 2.6.12-rc5-mm1 about half way through the -mm patchset. As I said already this patch is a lot simpler. The reclaim is turned on or off on a per-zone basis using a syscall. I haven't tested the x86 syscall, so it might be wrong. It uses the existing reclaim/pageout code with the small addition of a may_swap flag to scan_control (patch 1/4). I also added __GFP_NORECLAIM (patch 3/4) so that certain allocation types can be flagged to never cause reclaim. This was a deficiency that was in all of my earlier patch sets. Previously, doing a big buffered read would fill one zone with page cache and then start to reclaim from that same zone, leaving the other zones untouched. Adding some extra throttling on the reclaim was also required (patch 4/4). Without the machine would grind to a crawl when doing a "make -j" kernel build. Even with this patch the System Time is higher on average, but it seems tolerable. Here are some numbers for kernbench runs on a 2-node, 4cpu, 8Gig RAM Altix in the "make -j" run: wall user sys %cpu ctx sw. sleeps ---- ---- --- ---- ------ ------ No patch 1009 1384 847 258 298170 504402 w/patch, no reclaim 880 1376 667 288 254064 396745 w/patch & reclaim 1079 1385 926 252 291625 548873 These numbers are the average of 2 runs of 3 "make -j" runs done right after system boot. Run-to-run variability for "make -j" is huge, so these numbers aren't terribly useful except to seee that with reclaim the benchmark still finishes in a reasonable amount of time. I also looked at the NUMA hit/miss stats for the "make -j" runs and the reclaim doesn't make any difference when the machine is thrashing away. Doing a "make -j8" on a single node that is filled with page cache pages takes 700 seconds with reclaim turned on and 735 seconds without reclaim (due to remote memory accesses). The simple zone_reclaim syscall program is at http://www.bork.org/~mort/sgi/zone_reclaim.c This patch: This adds an extra switch to the scan_control struct. It simply lets the reclaim code know if its allowed to swap pages out. This was required for a simple per-zone reclaimer. Without this addition pages would be swapped out as soon as a zone ran out of memory and the early reclaim kicked in. Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: add /proc/zoneinfoNikita Danilov2005-06-21
| | | | | | | | | Add /proc/zoneinfo file to display information about memory zones. Useful to analyze VM behaviour. Signed-off-by: Nikita Danilov <nikita@clusterfs.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] madvise: merge the mapsPrasanna Meda2005-06-21
| | | | | | | | | | | | | This attempts to merge back the split maps. This code is mostly copied from Chrisw's mlock merging from post 2.6.11 trees. The only difference is in munmapped_error handling. Also passed prev to willneed/dontneed, eventhogh they do not handle it now, since I felt it will be cleaner, instead of handling prev in madvise_vma in some cases and in subfunction in some cases. Signed-off-by: Prasanna Meda <pmeda@akamai.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] madvise: do not split the mapsPrasanna Meda2005-06-21
| | | | | | | | | | This attempts to avoid splittings when it is not needed, that is when vm_flags are same as new flags. The idea is from the <2.6.11 mlock_fixup and others. This will provide base for the next madvise merging patch. Signed-off-by: Prasanna Meda <pmeda@akamai.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] vmscan: notice slab shrinkingakpm@osdl.org2005-06-21
| | | | | | | | | | | | | | | | | | | | | | Fix a problem identified by Andrea Arcangeli <andrea@suse.de> kswapd will set a zone into all_unreclaimable state if it sees that we're not successfully reclaiming LRU pages. But that fails to notice that we're successfully reclaiming slab obects, so we can set all_unreclaimable too soon. So change shrink_slab() to return a success indication if it actually reclaimed some objects, and don't assume that the zone is all_unreclaimable if that is true. This means that we won't enter all_unreclaimable state if we are successfully freeing slab objects but we're not yet actually freeing slab pages, due to internal fragmentation. (hm, this has a shortcoming. We could be successfully freeing ZONE_NORMAL slab objects while being really oom on ZONE_DMA. If that happens then kswapd might burn a lot of CPU. But given that there might be some slab objects in ZONE_DMA, perhaps that is appropriate.) Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [SLAB] Introduce kmem_cache_nameArnaldo Carvalho de Melo2005-06-19
| | | | | | | | | This is for use with slab users that pass a dynamically allocated slab name in kmem_cache_create, so that before destroying the slab one can retrieve the name and free its memory. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* [PATCH] broken fault_in_pages_readable call in generic_file_buffered_write()Martin Schwidefsky2005-06-06
| | | | | | | | | | fault_in_pages_readable() is being passed an incorrect `end' address, which can result in writes accidentally faulting in pages which will not be affected by the write() call. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] try_to_unmap_cluster() passes out-of-bounds pte to pte_unmap()William Lee Irwin III2005-05-24
| | | | | | | | | | | | | | | | | | | | | | | | try_to_unmap_cluster() does: for (pte = pte_offset_map(pmd, address); address < end; pte++, address += PAGE_SIZE) { ... } pte_unmap(pte); It may take a little staring to notice, but pte can actually fall off the end of the pte page in this iteration, which makes life difficult for kmap_atomic() and the users not expecting it to BUG(). Of course, we're somewhat lucky in that arithmetic elsewhere in the function guarantees that at least one iteration is made, lest this force larger rearrangements to be made. This issue and patch also apply to non-mm mainline and with trivial adjustments, at least two related kernels. Discovered during internal testing at Oracle. Signed-off-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix for __generic_file_aio_read() to return 0 on EOFSuparna Bhattacharya2005-05-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I came across the following problem while running ltp-aiodio testcases from ltp-full-20050405 on linux-2.6.12-rc3-mm3. I tried running the tests with EXT3 as well as JFS filesystems. One or two fsx-linux testcases were hung after some time. These testcases were hanging at wait_for_all_aios(). Debugging shows that there were some iocbs which were not getting completed eventhough the last retry for those returned -EIOCBQUEUED. Also all such pending iocbs represented READ operation. Further debugging revealed that all such iocbs hit EOF in the DIO layer. To be more precise, the "pos" from which they were trying to read was greater than the "size" of the file. So the generic_file_direct_IO returned 0. This happens rarely as there is already a check in __generic_file_aio_read(), for whether "pos" < "size" before calling direct IO routine. >size = i_size_read(inode); >if (pos < size) { > retval = generic_file_direct_IO(READ, iocb, > iov, pos, nr_segs); But for READ, we are taking the inode->i_sem only in the DIO layer. So it is possible that some other process can change the size of the file before we take the i_sem. In such a case ( when "pos" > "size"), the __generic_file_aio_read() would return -EIOCBQUEUED even though there were no I/O requests submitted by the DIO layer. This would cause the AIO layer to expect aio_complete() for THE iocb, which doesnot happen. And thus the test hangs forever, waiting for an I/O completion, where there are no requests submitted at all. The following patch makes __generic_file_aio_read() return 0 (instead of returning -EIOCBQUEUED), on getting 0 from generic_file_direct_IO(), so that the AIO layer does the aio_complete(). Testing: I have tested the patch on a SMP machine(with 2 Pentium 4 (HT)) running linux-2.6.12-rc3-mm3. I ran the ltp-aiodio testcases and none of the fsx-linux tests hung. Also the aio-stress tests ran without any problem. Signed-off-by: Suzuki K P <suzuki@in.ibm.com> Signed-off-by: Suparna Bhattacharya <suparna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Fixed guard page handling again in iounmapAndi Kleen2005-05-20
| | | | | | | | | | | | | | Caused oopses again. Also fix potential mismatch in checking if change_page_attr was needed. To do it without races I needed to change mm/vmalloc.c to export a __remove_vm_area that does not take vmlist lock. Noticed by Terence Ripperda and based on a patch of his. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Fix get_unmapped_area sanity testsLinus Torvalds2005-05-20
| | | | | | As noted by Chris Wright, we need to do the full range of tests regardless of whether MAP_FIXED is set or not, so re-organize get_unmapped_area() slightly to do the sanity checks unconditionally.
* [PATCH] prevent NULL mmap in topdown modelLinus Torvalds2005-05-19
| | | | | | | | | | | | | Prevent the topdown allocator from allocating mmap areas all the way down to address zero. We still allow a MAP_FIXED mapping of page 0 (needed for various things, ranging from Wine and DOSEMU to people who want to allow speculative loads off a NULL pointer). Tested by Chris Wright. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] do_swap_page() can map random data if swap read failsKirill Korotaev2005-05-17
| | | | | | | | | | | | There is a bug in do_swap_page(): when swap page happens to be unreadable, page filled with random data is mapped into user address space. The fix is to check for PageUptodate and send SIGBUS in case of error. Signed-Off-By: Kirill Korotaev <dev@sw.ru> Signed-Off-By: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swapout oops fixMcMullan, Jason2005-05-17
| | | | | | | | Fix OOPS when swapping on a device that doesn't have an unplug_io_fn defined (eg, ATA Over Ethernet) Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/nommu.c: try to fix __vmallocAdrian Bunk2005-05-17
| | | | | | | | | | Linus changed the second argument of __vmalloc from int to unsigned int breaking the compilation for CONFIG_MMU=n configurations (since he only changed vmalloc.c but not nommu.c). Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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