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2014-06-04hugetlb: restrict hugepage_migration_support() to x86_64Naoya Horiguchi
Currently hugepage migration is available for all archs which support pmd-level hugepage, but testing is done only for x86_64 and there're bugs for other archs. So to avoid breaking such archs, this patch limits the availability strictly to x86_64 until developers of other archs get interested in enabling this feature. Simply disabling hugepage migration on non-x86_64 archs is not enough to fix the reported problem where sys_move_pages() hits the BUG_ON() in follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is supported in vma_migratable(). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: migrate: check movability of hugepage in unmap_and_move_huge_page()Naoya Horiguchi
Currently hugepage migration works well only for pmd-based hugepages (mainly due to lack of testing,) so we had better not enable migration of other levels of hugepages until we are ready for it. Some users of hugepage migration (mbind, move_pages, and migrate_pages) do page table walk and check pud/pmd_huge() there, so they are safe. But the other users (softoffline and memory hotremove) don't do this, so without this patch they can try to migrate unexpected types of hugepages. To prevent this, we introduce hugepage_migration_support() as an architecture dependent check of whether hugepage are implemented on a pmd basis or not. And on some architecture multiple sizes of hugepages are available, so hugepage_migration_support() also checks hugepage size. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22mm: use vm_unmapped_area() in hugetlbfs on ia64 architectureMichel Lespinasse
Update the ia64 hugetlb_get_unmapped_area function to make use of vm_unmapped_area() instead of implementing a brute force search. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2011-01-13thp: pte alloc trans splittingAndrea Arcangeli
pte alloc routines must wait for split_huge_page if the pmd is not present and not null (i.e. pmd_trans_splitting). The additional branches are optimized away at compile time by pmd_trans_splitting if the config option is off. However we must pass the vma down in order to know the anon_vma lock to wait for. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2008-07-30GRU Driver: hardware data structuresJack Steiner
This series of patches adds a driver for the SGI UV GRU. The driver is still in development but it currently compiles for both x86_64 & IA64. All simple regression tests pass on IA64. Although features remain to be added, I'd like to start the process of getting the driver into the kernel. Additional kernel drivers will depend on services provide by the GRU driver. The GRU is a hardware resource located in the system chipset. The GRU contains memory that is mmaped into the user address space. This memory is used to communicate with the GRU to perform functions such as load/store, scatter/gather, bcopy, AMOs, etc. The GRU is directly accessed by user instructions using user virtual addresses. GRU instructions (ex., bcopy) use user virtual addresses for operands. The GRU contains a large TLB that is functionally very similar to processor TLBs. Because the external contains a TLB with user virtual address, it requires callouts from the core VM system when certain types of changes are made to the process page tables. There are several MMUOPS patches currently being discussed but none has been accepted into the kernel. The GRU driver is built using version V18 from Andrea Arcangeli. This patch: Contains the definitions of the hardware GRU data structures that are used by the driver to manage the GRU. [akpm@linux-foundation;org: export hpage_shift] Signed-off-by: Jack Steiner <steiner@sgi.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24hugetlb: introduce pud_hugeAndi Kleen
Straight forward extensions for huge pages located in the PUD instead of PMDs. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24hugetlb: modular state for hugetlb page sizeAndi Kleen
The goal of this patchset is to support multiple hugetlb page sizes. This is achieved by introducing a new struct hstate structure, which encapsulates the important hugetlb state and constants (eg. huge page size, number of huge pages currently allocated, etc). The hstate structure is then passed around the code which requires these fields, they will do the right thing regardless of the exact hstate they are operating on. This patch adds the hstate structure, with a single global instance of it (default_hstate), and does the basic work of converting hugetlb to use the hstate. Future patches will add more hstate structures to allow for different hugetlbfs mounts to have different page sizes. [akpm@linux-foundation.org: coding-style fixes] Acked-by: Adam Litke <agl@us.ibm.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24mm: remove double indirection on tlb parameter to free_pgd_range() & CoJan Beulich
The double indirection here is not needed anywhere and hence (at least) confusing. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Do not depend on MAX_ORDER when grouping pages by mobilityMel Gorman
Currently mobility grouping works at the MAX_ORDER_NR_PAGES level. This makes sense for the majority of users where this is also the huge page size. However, on platforms like ia64 where the huge page size is runtime configurable it is desirable to group at a lower order. On x86_64 and occasionally on x86, the hugepage size may not always be MAX_ORDER_NR_PAGES. This patch groups pages together based on the value of HUGETLB_PAGE_ORDER. It uses a compile-time constant if possible and a variable where the huge page size is runtime configurable. It is assumed that grouping should be done at the lowest sensible order and that the user would not want to override this. If this is not true, page_block order could be forced to a variable initialised via a boot-time kernel parameter. One potential issue with this patch is that IA64 now parses hugepagesz with early_param() instead of __setup(). __setup() is called after the memory allocator has been initialised and the pageblock bitmaps already setup. In tests on one IA64 there did not seem to be any problem with using early_param() and in fact may be more correct as it guarantees the parameter is handled before the parsing of hugepages=. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31hugepage: fix broken check for offset alignment in hugepage mappingsDavid Gibson
For hugepage mappings, the file offset, like the address and size, needs to be aligned to the size of a hugepage. In commit 68589bc353037f233fe510ad9ff432338c95db66, the check for this was moved into prepare_hugepage_range() along with the address and size checks. But since BenH's rework of the get_unmapped_area() paths leading up to commit 4b1d89290b62bb2db476c94c82cf7442aab440c8, prepare_hugepage_range() is only called for MAP_FIXED mappings, not for other mappings. This means we're no longer ever checking for an aligned offset - I've confirmed that mmap() will (apparently) succeed with a misaligned offset on both powerpc and i386 at least. This patch restores the check, removing it from prepare_hugepage_range() and putting it back into hugetlbfs_file_mmap(). I'm putting it there, rather than in the get_unmapped_area() path so it only needs to go in one place, than separately in the half-dozen or so arch-specific implementations of hugetlb_get_unmapped_area(). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Cc: Adam Litke <agl@us.ibm.com> Cc: Andi Kleen <ak@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-26[IA64] is_power_of_2-ia64/mm/hugetlbpage.cvignesh babu
Replacing (n & (n-1)) in the context of power of 2 checks with is_power_of_2 Signed-off-by: vignesh babu <vignesh.babu@wipro.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-05-08header cleaning: don't include smp_lock.h when not usedRandy Dunlap
Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07get_unmapped_area handles MAP_FIXED on ia64Benjamin Herrenschmidt
Handle MAP_FIXED in ia64 arch_get_unmapped_area and hugetlb_get_unmapped_area(), just call prepare_hugepage_range in the later and is_hugepage_only_range() in the former. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-07[PATCH] shared page table for hugetlb pageChen, Kenneth W
Following up with the work on shared page table done by Dave McCracken. This set of patch target shared page table for hugetlb memory only. The shared page table is particular useful in the situation of large number of independent processes sharing large shared memory segments. In the normal page case, the amount of memory saved from process' page table is quite significant. For hugetlb, the saving on page table memory is not the primary objective (as hugetlb itself already cuts down page table overhead significantly), instead, the purpose of using shared page table on hugetlb is to allow faster TLB refill and smaller cache pollution upon TLB miss. With PT sharing, pte entries are shared among hundreds of processes, the cache consumption used by all the page table is smaller and in return, application gets much higher cache hit ratio. One other effect is that cache hit ratio with hardware page walker hitting on pte in cache will be higher and this helps to reduce tlb miss latency. These two effects contribute to higher application performance. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: Dave McCracken <dmccr@us.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Adam Litke <agl@us.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-14[PATCH] hugetlb: prepare_hugepage_range check offset tooHugh Dickins
(David:) If hugetlbfs_file_mmap() returns a failure to do_mmap_pgoff() - for example, because the given file offset is not hugepage aligned - then do_mmap_pgoff will go to the unmap_and_free_vma backout path. But at this stage the vma hasn't been marked as hugepage, and the backout path will call unmap_region() on it. That will eventually call down to the non-hugepage version of unmap_page_range(). On ppc64, at least, that will cause serious problems if there are any existing hugepage pagetable entries in the vicinity - for example if there are any other hugepage mappings under the same PUD. unmap_page_range() will trigger a bad_pud() on the hugepage pud entries. I suspect this will also cause bad problems on ia64, though I don't have a machine to test it on. (Hugh:) prepare_hugepage_range() should check file offset alignment when it checks virtual address and length, to stop MAP_FIXED with a bad huge offset from unmapping before it fails further down. PowerPC should apply the same prepare_hugepage_range alignment checks as ia64 and all the others do. Then none of the alignment checks in hugetlbfs_file_mmap are required (nor is the check for too small a mapping); but even so, move up setting of VM_HUGETLB and add a comment to warn of what David Gibson discovered - if hugetlbfs_file_mmap fails before setting it, do_mmap_pgoff's unmap_region when unwinding from error will go the non-huge way, which may cause bad behaviour on architectures (powerpc and ia64) which segregate their huge mappings into a separate region of the address space. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Adam Litke <agl@us.ibm.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-22[IA64] fix ia64 is_hugepage_only_rangeChen, Kenneth W
fix is_hugepage_only_range() definition to be "overlaps" instead of "within architectural restricted hugetlb address range". Simplify the ia64 specific code that used to use is_hugepage_only_range() to just check which region the address is in. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-03-22[PATCH] hugepage: is_aligned_hugepage_range() cleanupDavid Gibson
Quite a long time back, prepare_hugepage_range() replaced is_aligned_hugepage_range() as the callback from mm/mmap.c to arch code to verify if an address range is suitable for a hugepage mapping. is_aligned_hugepage_range() stuck around, but only to implement prepare_hugepage_range() on archs which didn't implement their own. Most archs (everything except ia64 and powerpc) used the same implementation of is_aligned_hugepage_range(). On powerpc, which implements its own prepare_hugepage_range(), the custom version was never used. In addition, "is_aligned_hugepage_range()" was a bad name, because it suggests it returns true iff the given range is a good hugepage range, whereas in fact it returns 0-or-error (so the sense is reversed). This patch cleans up by abolishing is_aligned_hugepage_range(). Instead prepare_hugepage_range() is defined directly. Most archs use the default version, which simply checks the given region is aligned to the size of a hugepage. ia64 and powerpc define custom versions. The ia64 one simply checks that the range is in the correct address space region in addition to being suitably aligned. The powerpc version (just as previously) checks for suitable addresses, and if necessary performs low-level MMU frobbing to set up new areas for use by hugepages. No libhugetlbfs testsuite regressions on ppc64 (POWER5 LPAR). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-24[IA64] Rationalise Region DefinitionsPeter Chubb
Currently, region numbers are defined in several files, with several names. For example, we have REGION_KERNEL in asm/page.h and RGN_KERNEL in pgtable.h We also have address definitions that should depend on the RGN_XXX macros, but are currently just long constants. The following patch reorganises all the definitions so that they have the same form (RGN_XXX), are in one place, and that addresses that depend on RGN_XXX are derived from them. (This is a necessary but not sufficient patch to allow UML-like operation on IA64). Thanks to David Mosberger for catching the change I missed in mmu_context.h. Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au> Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-06-21[PATCH] Hugepage consolidationDavid Gibson
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>
2005-04-19[PATCH] freepgt: hugetlb_free_pgd_rangeHugh Dickins
ia64 and ppc64 had hugetlb_free_pgtables functions which were no longer being called, and it wasn't obvious what to do about them. The ppc64 case turns out to be easy: the associated tables are noted elsewhere and freed later, safe to either skip its hugetlb areas or go through the motions of freeing nothing. Since ia64 does need a special case, restore to ppc64 the special case of skipping them. The ia64 hugetlb case has been broken since pgd_addr_end went in, though it probably appeared to work okay if you just had one such area; in fact it's been broken much longer if you consider a long munmap spanning from another region into the hugetlb region. In the ia64 hugetlb region, more virtual address bits are available than in the other regions, yet the page tables are structured the same way: the page at the bottom is larger. Here we need to scale down each addr before passing it to the standard free_pgd_range. Was about to write a hugely_scaled_down macro, but found htlbpage_to_page already exists for just this purpose. Fixed off-by-one in ia64 is_hugepage_only_range. Uninline free_pgd_range to make it available to ia64. Make sure the vma-gathering loop in free_pgtables cannot join a hugepage_only_range to any other (safe to join huges? probably but don't bother). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-19[PATCH] freepgt: free_pgtables use vma listHugh Dickins
Recent woes with some arches needing their own pgd_addr_end macro; and 4-level clear_page_range regression since 2.6.10's clear_page_tables; and its long-standing well-known inefficiency in searching throughout the higher-level page tables for those few entries to clear and free: all can be blamed on ignoring the list of vmas when we free page tables. Replace exit_mmap's clear_page_range of the total user address space by free_pgtables operating on the mm's vma list; unmap_region use it in the same way, giving floor and ceiling beyond which it may not free tables. This brings lmbench fork/exec/sh numbers back to 2.6.10 (unless preempt is enabled, in which case latency fixes spoil unmap_vmas throughput). Beware: the do_mmap_pgoff driver failure case must now use unmap_region instead of zap_page_range, since a page table might have been allocated, and can only be freed while it is touched by some vma. Move free_pgtables from mmap.c to memory.c, where its lower levels are adapted from the clear_page_range levels. (Most of free_pgtables' old code was actually for a non-existent case, prev not properly set up, dating from before hch gave us split_vma.) Pass mmu_gather** in the public interfaces, since we might want to add latency lockdrops later; but no attempt to do so yet, going by vma should itself reduce latency. But what if is_hugepage_only_range? Those ia64 and ppc64 cases need careful examination: put that off until a later patch of the series. What of x86_64's 32bit vdso page __map_syscall32 maps outside any vma? And the range to sparc64's flush_tlb_pgtables? It's less clear to me now that we need to do more than is done here - every PMD_SIZE ever occupied will be flushed, do we really have to flush every PGDIR_SIZE ever partially occupied? A shame to complicate it unnecessarily. Special thanks to David Miller for time spent repairing my ceilings. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!