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* Allow arbitrary read-only shared pfn-remapping tooLinus Torvalds2005-12-11
| | | | | | | | | | | | | The VM layer (for historical reasons) turns a read-only shared mmap into a private-like mapping with the VM_MAYWRITE bit clear. Thus checking just VM_SHARED isn't actually sufficient. So use a trivial helper function for the cases where we wanted to inquire if a mapping was COW-like or not. Moo! Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Remove (at least temporarily) the "incomplete PFN mapping" supportLinus Torvalds2005-12-11
| | | | | | | | | With the previous commit, we can handle arbitrary shared re-mappings even without this complexity, and since the only known private mappings are for strange users of /dev/mem (which never create an incomplete one), there seems to be no reason to support it. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Allow arbitrary shared PFNMAP'sLinus Torvalds2005-12-11
| | | | | | | | | | | A shared mapping doesn't cause COW-pages, so we don't need to worry about the whole vm_pgoff logic to decide if a PFN-remapped page has gone through COW or not. This makes it possible to entirely avoid the special "partial remapping" logic for the common case. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Make vm_insert_page() available to NVidia moduleLinus Torvalds2005-12-03
| | | | | | | | It used to use remap_pfn_range(), which wasn't GPL-only either, and the new interface is actually simpler and does more checking, so we shouldn't unnecessarily discourage people from switching over. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix up per-cpu page batch sizesNick Piggin2005-12-03
| | | | | | | | | The code to clamp batch sizes to 2^n - 1 went missing and an extra check got added, which must have been a hunk of the "higer order pcp batch refills" work sneaking in. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* VM: add "vm_insert_page()" functionLinus Torvalds2005-11-30
| | | | | | | | | | | | | This is what a lot of drivers will actually want to use to insert individual pages into a user VMA. It doesn't have the old PageReserved restrictions of remap_pfn_range(), and it doesn't complain about partial remappings. The page you insert needs to be a nice clean kernel allocation, so you can't insert arbitrary page mappings with this, but that's not what people want. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VM: Fix typos in get_locked_pteTrond Myklebust2005-11-29
| | | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] pfnmap: do_no_page BUG_ON againHugh Dickins2005-11-29
| | | | | | | | | | Use copy_user_highpage directly instead of cow_user_page in do_no_page: in the immediately following page_cache_release, and elsewhere, it is assuming that new_page is normal. If any VM_PFNMAP driver can get to do_no_page, it's just a BUG (but not in the case of do_anonymous_page). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] pfnmap: remove src_page from do_wp_pageHugh Dickins2005-11-29
| | | | | | | Clean away do_wp_page's "src_page": cow_user_page makes it unnecessary. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* cow_user_page: fix page alignmentLinus Torvalds2005-11-29
| | | | | | | | | High Dickins points out that the user virtual address passed to the page fault handler isn't necessarily page-aligned. Also, add a comment on why the copy could fail for the user address case. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* VM: add common helper function to create the page tablesLinus Torvalds2005-11-29
| | | | | | This logic was duplicated four times, for no good reason. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Support strange discontiguous PFN remappingsLinus Torvalds2005-11-29
| | | | | | | | | | | | | These get created by some drivers that don't generally even want a pfn remapping at all, but would really mostly prefer to just map pages they've allocated individually instead. For now, create a helper function that turns such an incomplete PFN remapping call into a loop that does that explicit mapping. In the long run we almost certainly want to export a totally different interface for that, though. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix missing pfn variables caused by vm changesBen Collins2005-11-29
| | | | | | | | | I image this showed up because of "unused var..." when the changes occured, because flush_cache_page() is a noop in most places. This showed up for me on parisc however, where flush_cache_page() is a real function. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix vma argument in get_usr_pages() for gate areasNick Piggin2005-11-29
| | | | | | | | The system call gate area handling called vm_normal_page() with the wrong vma (which was always NULL, and caused an oops). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] shrinker->nr = LONG_MAX means deadlock for icacheAndrea Arcangeli2005-11-28
| | | | | | | | | | | | | | | | | | | | | | With Andrew Morton <akpm@osdl.org> The slab scanning code tries to balance the scanning rate of slabs versus the scanning rate of LRU pages. To do this, it retains state concerning how many slabs have been scanned - if a particular slab shrinker didn't scan enough objects, we remember that for next time, and scan more objects on the next pass. The problem with this is that with (say) a huge number of GFP_NOIO direct-reclaim attempts, the number of objects which are to be scanned when we finally get a GFP_KERNEL request can be huge. Because some shrinker handlers just bail out if !__GFP_FS. So the patch clamps the number of objects-to-be-scanned to 2* the total number of objects in the slab cache. Signed-off-by: Andrea Arcangeli <andrea@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] temporarily disable swap token on memory pressureRik van Riel2005-11-28
| | | | | | | | | | | | | | | | | | | | Some users (hi Zwane) have seen a problem when running a workload that eats nearly all of physical memory - th system does an OOM kill, even when there is still a lot of swap free. The problem appears to be a very big task that is holding the swap token, and the VM has a very hard time finding any other page in the system that is swappable. Instead of ignoring the swap token when sc->priority reaches 0, we could simply take the swap token away from the memory hog and make sure we don't give it back to the memory hog for a few seconds. This patch resolves the problem Zwane ran into. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: __alloc_pages cleanup fixNick Piggin2005-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I believe this patch is required to fix breakage in the asynch reclaim watermark logic introduced by this patch: http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=7fb1d9fca5c6e3b06773b69165a73f3fb786b8ee Just some background of the watermark logic in case it isn't clear... Basically what we have is this: --- pages_high | | (a) | --- pages_low | | (b) | --- pages_min | | (c) | --- 0 Now when pages_low is reached, we want to kick asynch reclaim, which gives us an interval of "b" before we must start synch reclaim, and gives kswapd an interval of "a" before it need go back to sleep. When pages_min is reached, normal allocators must enter synch reclaim, but PF_MEMALLOC, ALLOC_HARDER, and ALLOC_HIGH (ie. atomic allocations, recursive allocations, etc.) get access to varying amounts of the reserve "c". Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Seth, Rohit" <rohit.seth@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Workaround for gcc 2.96 (undefined references)Alan Stern2005-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LD .tmp_vmlinux1 mm/built-in.o(.text+0x100d6): In function `copy_page_range': : undefined reference to `__pud_alloc' mm/built-in.o(.text+0x1010b): In function `copy_page_range': : undefined reference to `__pmd_alloc' mm/built-in.o(.text+0x11ef4): In function `__handle_mm_fault': : undefined reference to `__pud_alloc' fs/built-in.o(.text+0xc930): In function `install_arg_page': : undefined reference to `__pud_alloc' make: *** [.tmp_vmlinux1] Error 1 Those missing references in mm/memory.c arise from this code in include/linux/mm.h, combined with the fact that __PGTABLE_PMD_FOLDED and __PGTABLE_PUD_FOLDED are both set and __ARCH_HAS_4LEVEL_HACK is not: /* * The following ifdef needed to get the 4level-fixup.h header to work. * Remove it when 4level-fixup.h has been removed. */ #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK) static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) { return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))? NULL: pud_offset(pgd, address); } static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) { return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))? NULL: pmd_offset(pud, address); } #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */ With my configuration the pgd_none and pud_none routines are inlines returning a constant 0. Apparently the old compiler avoids generating calls to __pud_alloc and __pmd_alloc but still lists them as undefined references in the module's symbol table. I don't know which change caused this problem. I think it was added somewhere between 2.6.14 and 2.6.15-rc1, because I remember building several 2.6.14-rc kernels without difficulty. However I can't point to an individual culprit. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* mm: re-architect the VM_UNPAGED logicLinus Torvalds2005-11-28
| | | | | | | | | | | | | | | | This replaces the (in my opinion horrible) VM_UNMAPPED logic with very explicit support for a "remapped page range" aka VM_PFNMAP. It allows a VM area to contain an arbitrary range of page table entries that the VM never touches, and never considers to be normal pages. Any user of "remap_pfn_range()" automatically gets this new functionality, and doesn't even have to mark the pages reserved or indeed mark them any other way. It just works. As a side effect, doing mmap() on /dev/mem works for arbitrary ranges. Sparc update from David in the next commit. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] 32bit integer overflow in invalidate_inode_pages2()Oleg Drokin2005-11-23
| | | | | | | Fix a 32 bit integer overflow in invalidate_inode_pages2_range. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: update split ptlock KconfigHugh Dickins2005-11-23
| | | | | | | | | | | | | | | | | | | Closer attention to the arithmetic shows that neither ppc64 nor sparc really uses one page for multiple page tables: how on earth could they, while pte_alloc_one returns just a struct page pointer, with no offset? Well, arm26 manages it by returning a pte_t pointer cast to a struct page pointer, harumph, then compensating in its pmd_populate. But arm26 is never SMP, so it's not a problem for split ptlock either. And the PA-RISC situation has been recently improved: CONFIG_PA20 works without the 16-byte alignment which inflated its spinlock_t. But the current union of spinlock_t with private does make the 7xxx struct page significantly larger, even without debug, so disable its split ptlock. 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] hugetlb: fix race in set_max_huge_pages for multiple updaters of ↵Eric Paris2005-11-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nr_huge_pages If there are multiple updaters to /proc/sys/vm/nr_hugepages simultaneously it is possible for the nr_huge_pages variable to become incorrect. There is no locking in the set_max_huge_pages function around alloc_fresh_huge_page which is able to update nr_huge_pages. Two callers to alloc_fresh_huge_page could race against each other as could a call to alloc_fresh_huge_page and a call to update_and_free_page. This patch just expands the area covered by the hugetlb_lock to cover the call into alloc_fresh_huge_page. I'm not sure how we could say that a sysctl section is performance critical where more specific locking would be needed. My reproducer was to run a couple copies of the following script simultaneously while [ true ]; do echo 1000 > /proc/sys/vm/nr_hugepages echo 500 > /proc/sys/vm/nr_hugepages echo 750 > /proc/sys/vm/nr_hugepages echo 100 > /proc/sys/vm/nr_hugepages echo 0 > /proc/sys/vm/nr_hugepages done and then watch /proc/meminfo and eventually you will see things like HugePages_Total: 100 HugePages_Free: 109 After applying the patch all seemed well. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] unpaged: PG_reserved bad_pageHugh Dickins2005-11-22
| | | | | | | | | | | It used to be the case that PG_reserved pages were silently never freed, but in 2.6.15-rc1 they may be freed with a "Bad page state" message. We should work through such cases as they appear, fixing the code; but for now it's safer to issue the message without freeing the page, leaving PG_reserved set. 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] unpaged: ZERO_PAGE in VM_UNPAGEDHugh Dickins2005-11-22
| | | | | | | | | | | | | It's strange enough to be looking out for anonymous pages in VM_UNPAGED areas, let's not insert the ZERO_PAGE there - though whether it would matter will depend on what we decide about ZERO_PAGE refcounting. But whereas do_anonymous_page may (exceptionally) be called on a VM_UNPAGED area, do_no_page should never be: just BUG_ON. 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] unpaged: anon in VM_UNPAGEDHugh Dickins2005-11-22
| | | | | | | | | | | | | | | | | | | | | | copy_one_pte needs to copy the anonymous COWed pages in a VM_UNPAGED area, zap_pte_range needs to free them, do_wp_page needs to COW them: just like ordinary pages, not like the unpaged. But recognizing them is a little subtle: because PageReserved is no longer a condition for remap_pfn_range, we can now mmap all of /dev/mem (whether the distro permits, and whether it's advisable on this or that architecture, is another matter). So if we can see a PageAnon, it may not be ours to mess with (or may be ours from elsewhere in the address space). I suspect there's an entertaining insoluble self-referential problem here, but the page_is_anon function does a good practical job, and MAP_PRIVATE PROT_WRITE VM_UNPAGED will always be an odd choice. In updating the comment on page_address_in_vma, noticed a potential NULL dereference, in a path we don't actually take, but fixed it. 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] unpaged: COW on VM_UNPAGEDHugh Dickins2005-11-22
| | | | | | | | | | | | | | | Remove the BUG_ON(vma->vm_flags & VM_UNPAGED) from do_wp_page, and let it do Copy-On-Write without touching the VM_UNPAGED's page counts - but this is incomplete, because the anonymous page it inserts will itself need to be handled, here and in other functions - next patch. We still don't copy the page if the pfn is invalid, because the copy_user_highpage interface does not allow it. But that's not been a problem in the past: can be added in later if the need arises. 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] unpaged: VM_NONLINEAR VM_RESERVEDHugh Dickins2005-11-22
| | | | | | | | | | | | | | | | There's one peculiar use of VM_RESERVED which the previous patch left behind: because VM_NONLINEAR's try_to_unmap_cluster uses vm_private_data as a swapout cursor, but should never meet VM_RESERVED vmas, it was a way of extending VM_NONLINEAR to VM_RESERVED vmas using vm_private_data for some other purpose. But that's an empty set - they don't have the populate function required. So just throw away those VM_RESERVED tests. But one more interesting in rmap.c has to go too: try_to_unmap_one will want to swap out an anonymous page from VM_RESERVED or VM_UNPAGED area. 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] unpaged: VM_UNPAGEDHugh Dickins2005-11-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although we tend to associate VM_RESERVED with remap_pfn_range, quite a few drivers set VM_RESERVED on areas which are then populated by nopage. The PageReserved removal in 2.6.15-rc1 changed VM_RESERVED not to free pages in zap_pte_range, without changing those drivers not to set it: so their pages just leak away. Let's not change miscellaneous drivers now: introduce VM_UNPAGED at the core, to flag the special areas where the ptes may have no struct page, or if they have then it's not to be touched. Replace most instances of VM_RESERVED in core mm by VM_UNPAGED. Force it on in remap_pfn_range, and the sparc and sparc64 io_remap_pfn_range. Revert addition of VM_RESERVED to powerpc vdso, it's not needed there. Is it needed anywhere? It still governs the mm->reserved_vm statistic, and special vmas not to be merged, and areas not to be core dumped; but could probably be eliminated later (the drivers are probably specifying it because in 2.4 it kept swapout off the vma, but in 2.6 we work from the LRU, which these pages don't get on). Use the VM_SHM slot for VM_UNPAGED, and define VM_SHM to 0: it serves no purpose whatsoever, and should be removed from drivers when we clean up. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] unpaged: unifdefed PageCompoundHugh Dickins2005-11-22
| | | | | | | | | | | | | | | | | It looks like snd_xxx is not the only nopage to be using PageReserved as a way of holding a high-order page together: which no longer works, but is masked by our failure to free from VM_RESERVED areas. We cannot fix that bug without first substituting another way to hold the high-order page together, while farming out the 0-order pages from within it. That's just what PageCompound is designed for, but it's been kept under CONFIG_HUGETLB_PAGE. Remove the #ifdefs: which saves some space (out- of-line put_page), doesn't slow down what most needs to be fast (already using hugetlb), and unifies the way we handle high-order pages. 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] unpaged: private write VM_RESERVEDHugh Dickins2005-11-22
| | | | | | | | | | | | | | | | | | The PageReserved removal in 2.6.15-rc1 issued a "deprecated" message when you tried to mmap or mprotect MAP_PRIVATE PROT_WRITE a VM_RESERVED, and failed with -EACCES: because do_wp_page lacks the refinement to COW pages in those areas, nor do we expect to find anonymous pages in them; and it seemed just bloat to add code for handling such a peculiar case. But immediately it caused vbetool and ddcprobe (using lrmi) to fail. So revert the "deprecated" messages, letting mmap and mprotect succeed. But leave do_wp_page's BUG_ON(vma->vm_flags & VM_RESERVED) in place until we've added the code to do it right: so this particular patch is only good if the app doesn't really need to write to that private area. 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] unpaged: get_user_pages VM_RESERVEDHugh Dickins2005-11-22
| | | | | | | | | | | | | | | | | The PageReserved removal in 2.6.15-rc1 prohibited get_user_pages on the areas flagged VM_RESERVED in place of PageReserved. That is correct in theory - we ought not to interfere with struct pages in such a reserved area; but in practice it broke BTTV for one. So revert to prohibiting only on VM_IO: if someone gets into trouble with get_user_pages on VM_RESERVED, it'll just be a "don't do that". You can argue that videobuf_mmap_mapper shouldn't set VM_RESERVED in the first place, but now's not the time for breaking drivers without notice. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge branch 'master'Kyle McMartin2005-11-18
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| * [PATCH] re-export clear_page_dirty_for_io()Hans Reiser2005-11-18
| | | | | | | | | | | | | | | | | | 2.6.14 has this exported, and reiser4 (at least) uses it. Put things back the way they were. Signed-off-by: Vladimir V. Saveliev <vs@namesys.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PARISC] Fix compile warning caused by conflicting types of expand_upwards()Matthew Wilcox2005-11-18
|/ | | | | | | | Fix compile warning caused by conflicting types of expand_upwards. IA64 requires it to not be static inline, as it's used outside mm/mmap.c Signed-off-by: Matthew Wilcox <willy@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
* [PATCH] VM: fix zone list restart in page allocatateJens Axboe2005-11-17
| | | | | | | | | We must reassign z before looping through the zones kicking kswapd, since it will be NULL if we hit an OOM condition and jump back to the beginning again. 'z' is initially assigned before the restart: label. So move the restart label up a little. Signed-off-by: Jens Axboe <axboe@suse.de>
* Merge x86-64 update from AndiLinus Torvalds2005-11-14
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| * [PATCH] x86_64: Remove obsolete ARCH_HAS_ATOMIC_UNSIGNED and page_flags_tAndi Kleen2005-11-14
| | | | | | | | | | | | | | | | | | Has been introduced for x86-64 at some point to save memory in struct page, but has been obsolete for some time. Just remove it. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| * [PATCH] x86_64: When cpu_up fails clean up page allocator properlyAndi Kleen2005-11-14
| | | | | | | | | | Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| * [PATCH] x86_64: Add 4GB DMA32 zoneAndi Kleen2005-11-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new 4GB GFP_DMA32 zone between the GFP_DMA and GFP_NORMAL zones. As a bit of historical background: when the x86-64 port was originally designed we had some discussion if we should use a 16MB DMA zone like i386 or a 4GB DMA zone like IA64 or both. Both was ruled out at this point because it was in early 2.4 when VM is still quite shakey and had bad troubles even dealing with one DMA zone. We settled on the 16MB DMA zone mainly because we worried about older soundcards and the floppy. But this has always caused problems since then because device drivers had trouble getting enough DMA able memory. These days the VM works much better and the wide use of NUMA has proven it can deal with many zones successfully. So this patch adds both zones. This helps drivers who need a lot of memory below 4GB because their hardware is not accessing more (graphic drivers - proprietary and free ones, video frame buffer drivers, sound drivers etc.). Previously they could only use IOMMU+16MB GFP_DMA, which was not enough memory. Another common problem is that hardware who has full memory addressing for >4GB misses it for some control structures in memory (like transmit rings or other metadata). They tended to allocate memory in the 16MB GFP_DMA or the IOMMU/swiotlb then using pci_alloc_consistent, but that can tie up a lot of precious 16MB GFPDMA/IOMMU/swiotlb memory (even on AMD systems the IOMMU tends to be quite small) especially if you have many devices. With the new zone pci_alloc_consistent can just put this stuff into memory below 4GB which works better. One argument was still if the zone should be 4GB or 2GB. The main motivation for 2GB would be an unnamed not so unpopular hardware raid controller (mostly found in older machines from a particular four letter company) who has a strange 2GB restriction in firmware. But that one works ok with swiotlb/IOMMU anyways, so it doesn't really need GFP_DMA32. I chose 4GB to be compatible with IA64 and because it seems to be the most common restriction. The new zone is so far added only for x86-64. For other architectures who don't set up this new zone nothing changes. Architectures can set a compatibility define in Kconfig CONFIG_DMA_IS_DMA32 that will define GFP_DMA32 as GFP_DMA. Otherwise it's a nop because on 32bit architectures it's normally not needed because GFP_NORMAL (=0) is DMA able enough. One problem is still that GFP_DMA means different things on different architectures. e.g. some drivers used to have #ifdef ia64 use GFP_DMA (trusting it to be 4GB) #elif __x86_64__ (use other hacks like the swiotlb because 16MB is not enough) ... . This was quite ugly and is now obsolete. These should be now converted to use GFP_DMA32 unconditionally. I haven't done this yet. Or best only use pci_alloc_consistent/dma_alloc_coherent which will use GFP_DMA32 transparently. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] slab: remove alloc_pages() callsChristoph Lameter2005-11-13
| | | | | | | | | | | | | | | | | | | | | | The slab allocator never uses alloc_pages since kmem_getpages() is always called with a valid nodeid. Remove the branch and the code from kmem_getpages() Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] slab: convert cache to page mapping macrosPekka Enberg2005-11-13
| | | | | | | | | | | | | | | | | | | | This patch converts object cache <-> page mapping macros to static inline functions to make the more explicit and readable. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mm: highmem watermarksNick Piggin2005-11-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pages_high - pages_low and pages_low - pages_min deltas are the asynch reclaim watermarks. As such, the should be in the same ratios as any other zone for highmem zones. It is the pages_min - 0 delta which is the PF_MEMALLOC reserve, and this is the region that isn't very useful for highmem. This patch ensures highmem systems have similar characteristics as non highmem ones with the same amount of memory, and also that highmem zones get similar reclaim pressures to other zones. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mm: __alloc_pages cleanupRohit Seth2005-11-13
| | | | | | | | | | | | | | | | | | | | | | | | Clean up of __alloc_pages. Restoration of previous behaviour, plus further cleanups by introducing an 'alloc_flags', removing the last of should_reclaim_zone. Signed-off-by: Rohit Seth <rohit.seth@intel.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mm: ZAP_BLOCK causes redundant workRobin Holt2005-11-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The address based work estimate for unmapping (for lockbreak) is and always was horribly inefficient for sparse mappings. The problem is most simply explained with an example: If we find a pgd is clear, we still have to call into unmap_page_range PGDIR_SIZE / ZAP_BLOCK_SIZE times, each time checking the clear pgd, in order to progress the working address to the next pgd. The fundamental way to solve the problem is to keep track of the end address we've processed and pass it back to the higher layers. From: Nick Piggin <npiggin@suse.de> Modification to completely get away from address based work estimate and instead use an abstract count, with a very small cost for empty entries as opposed to present pages. On 2.6.14-git2, ppc64, and CONFIG_PREEMPT=y, mapping and unmapping 1TB of virtual address space takes 1.69s; with the following patch applied, this operation can be done 1000 times in less than 0.01s From: Andrew Morton <akpm@osdl.org> With CONFIG_HUTETLB_PAGE=n: mm/memory.c: In function `unmap_vmas': mm/memory.c:779: warning: division by zero Due to zap_work -= (end - start) / (HPAGE_SIZE / PAGE_SIZE); So make the dummy HPAGE_SIZE non-zero Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mm: __GFP_NOFAIL fixKirill Korotaev2005-11-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In __alloc_pages(): if ((p->flags & (PF_MEMALLOC | PF_MEMDIE)) && !in_interrupt()) { /* go through the zonelist yet again, ignoring mins */ for (i = 0; zones[i] != NULL; i++) { struct zone *z = zones[i]; page = buffered_rmqueue(z, order, gfp_mask); if (page) { zone_statistics(zonelist, z); goto got_pg; } } goto nopage; <<<< HERE!!! FAIL... } kswapd (which has PF_MEMALLOC flag) can fail to allocate memory even when it allocates it with __GFP_NOFAIL flag. Signed-Off-By: Pavel Emelianov <xemul@sw.ru> Signed-Off-By: Denis Lunev <den@sw.ru> Signed-Off-By: Kirill Korotaev <dev@sw.ru> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds2005-11-11
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| * | mm/slab.c: fix a comment typoAdrian Bunk2005-11-08
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* | | [PATCH] Don't print per-cpu vm stats for offline cpus.Dave Jones2005-11-10
|/ / | | | | | | | | | | | | | | I just hit a page allocation error on a kernel configured to support 64 CPUs. It spewed 60 completely useless unnecessary lines of info. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mm/swap_state.c: unexport swapper_spaceAdrian Bunk2005-11-07
| | | | | | | | | | | | | | | | I didn't find any possible modular usage in the kernel. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mm/swapfile.c: unexport total_swap_pagesAdrian Bunk2005-11-07
| | | | | | | | | | | | | | | | I didn't find any possible modular usage in the kernel. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>