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* | [PATCH] unexport hugetlb_total_pagesAdrian Bunk2005-11-071-1/+0
| | | | | | | | | | | | | | | | 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/{mmap,nommu}.c: several unexportsAdrian Bunk2005-11-072-8/+0
| | | | | | | | | | | | | | | | | | | | I didn't find any possible modular usage in the kernel. This patch was already ACK'ed by Christoph Hellwig. 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] kernel-doc: fix warnings in vmalloc.cRandy Dunlap2005-11-071-2/+2
| | | | | | | | | | | | | | | | Fix new kernel-doc errors in vmalloc.c. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] more kernel-doc cleanups, additionsRandy Dunlap2005-11-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | Various core kernel-doc cleanups: - add missing function parameters in ipc, irq/manage, kernel/sys, kernel/sysctl, and mm/slab; - move description to just above function for kernel_restart() Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] readahead commentaryAndrew Morton2005-11-071-9/+22
| | | | | | | | | | | | | | | | | | | | Add a few comments surrounding the generic readahead API. Also convert some ulongs into pgoff_t: the identifier for PAGE_CACHE_SIZE offsets into pagecache. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] slab: Use same schedule timeout for all cpus in cache_reapManfred Spraul2005-11-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chen noticed that cache_reap uses REAPTIMEOUT_CPUC+smp_processor_id() as the timeout for rescheduling. The "+smp_processor_id()" part is wrong, the timeout should be identical for all cpus: start_cpu_timer already adds a cpu dependant offset to avoid any clustering. The attached patch removes smp_processor_id(). Signed-Off-By: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mm: rename kmem_cache_s to kmem_cachePekka J Enberg2005-11-071-1/+1
| | | | | | | | | | | | | | | | | | This patch renames struct kmem_cache_s to kmem_cache so we can start using it instead of kmem_cache_t typedef. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] slab: don't BUG on duplicated cacheAndrew Morton2005-11-071-33/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | slab presently goes BUG if someone tries to register an already-registered cache. But this can happen if the user accidentally loads a module which is already statically linked into the kernel. Nuking the kernel is rather a harsh reaction. Change it into a warning, and just fail the kmem_cache_alloc() attempt. If the module is well-behaved, the modprobe will fail and all is well. Notes: - Swaps the ranking of cache_chain_sem and lock_cpu_hotplug(). Doesn't seem important. Acked-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] Suppress split ptlock on arches which may use one page for multiple ↵Hugh Dickins2005-11-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | page tables Suppress split ptlock on arches which may use one page for multiple page tables. Reconsider what better to do (particularly on ppc64) later 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] ppc64: support 64k pagesBenjamin Herrenschmidt2005-11-061-0/+3
|/ | | | | | | | | | | | | | | Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel base page size to 64K. The resulting kernel still boots on any hardware. On current machines with 4K pages support only, the kernel will maintain 16 "subpages" for each 64K page transparently. Note that while real 64K capable HW has been tested, the current patch will not enable it yet as such hardware is not released yet, and I'm still verifying with the firmware architects the proper to get the information from the newer hypervisors. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Export __pagevec_release and pagevec_lookup_tagSteve French2005-11-011-0/+3
| | | | | | | These are needed to implement cifs_writepages Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
* [PATCH] Error checks omitted in init_tmpfs() in mm/tiny-shmem.cMatt Mackall2005-10-301-1/+4
| | | | | | | | | From: Hareesh Nagarajan <hnagar2@gmail.com> Signed-off-by: Hareesh Nagarajan <hnagar2@gmail.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] RCU torture-testing kernel modulePaul E. McKenney2005-10-301-1/+1
| | | | | | | | | | | | | | | | | | | | This patch is a rewrite of the one submitted on October 1st, using modules (http://marc.theaimsgroup.com/?l=linux-kernel&m=112819093522998&w=2). This rewrite adds a tristate CONFIG_RCU_TORTURE_TEST, which enables an intense torture test of the RCU infratructure. This is needed due to the continued changes to the RCU infrastructure to accommodate dynamic ticks, CPU hotplug, realtime, and so on. Most of the code is in a separate file that is compiled only if the CONFIG variable is set. Documentation on how to run the test and interpret the output is also included. This code has been tested on i386 and ppc64, and an earlier version of the code has received extensive testing on a number of architectures as part of the PREEMPT_RT patchset. Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] vm: remove redundant assignment from __pagevec_release_nonlru()Tejun Heo2005-10-301-1/+0
| | | | | | | | | | This patch removes redundant assignment from __pagevec_release_nonlru(). pages_to_free.cold is set to pvec->cold by pagevec_init() call right above the assignment. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fs: error case fix in __generic_file_aio_readTejun Heo2005-10-301-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When __generic_file_aio_read() hits an error during reading, it reports the error iff nothing has successfully been read yet. This is condition - when an error occurs, if nothing has been read/written, report the error code; otherwise, report the amount of bytes successfully transferred upto that point. This corner case can be exposed by performing readv(2) with the following iov. iov[0] = len0 @ ptr0 iov[1] = len1 @ NULL (or any other invalid pointer) iov[2] = len2 @ ptr2 When file size is enough, performing above readv(2) results in len0 bytes from file_pos @ ptr0 len2 bytes from file_pos + len0 @ ptr2 And the return value is len0 + len2. Test program is attached to this mail. This patch makes __generic_file_aio_read()'s error handling identical to other functions. #include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include <sys/uio.h> #include <errno.h> #include <string.h> int main(int argc, char **argv) { const char *path; struct stat stbuf; size_t len0, len1; void *buf0, *buf1; struct iovec iov[3]; int fd, i; ssize_t ret; if (argc < 2) { fprintf(stderr, "Usage: testreadv path (better be a " "small text file)\n"); return 1; } path = argv[1]; if (stat(path, &stbuf) < 0) { perror("stat"); return 1; } len0 = stbuf.st_size / 2; len1 = stbuf.st_size - len0; if (!len0 || !len1) { fprintf(stderr, "Dude, file is too small\n"); return 1; } if ((fd = open(path, O_RDONLY)) < 0) { perror("open"); return 1; } if (!(buf0 = malloc(len0)) || !(buf1 = malloc(len1))) { perror("malloc"); return 1; } memset(buf0, 0, len0); memset(buf1, 0, len1); iov[0].iov_base = buf0; iov[0].iov_len = len0; iov[1].iov_base = NULL; iov[1].iov_len = len1; iov[2].iov_base = buf1; iov[2].iov_len = len1; printf("vector "); for (i = 0; i < 3; i++) printf("%p:%zu ", iov[i].iov_base, iov[i].iov_len); printf("\n"); ret = readv(fd, iov, 3); if (ret < 0) perror("readv"); printf("readv returned %zd\nbuf0 = [%s]\nbuf1 = [%s]\n", ret, (char *)buf0, (char *)buf1); return 0; } Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpusets: automatic numa mempolicy rebindingPaul Jackson2005-10-301-0/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch automatically updates a tasks NUMA mempolicy when its cpuset memory placement changes. It does so within the context of the task, without any need to support low level external mempolicy manipulation. If a system is not using cpusets, or if running on a system with just the root (all-encompassing) cpuset, then this remap is a no-op. Only when a task is moved between cpusets, or a cpusets memory placement is changed does the following apply. Otherwise, the main routine below, rebind_policy() is not even called. When mixing cpusets, scheduler affinity, and NUMA mempolicies, the essential role of cpusets is to place jobs (several related tasks) on a set of CPUs and Memory Nodes, the essential role of sched_setaffinity is to manage a jobs processor placement within its allowed cpuset, and the essential role of NUMA mempolicy (mbind, set_mempolicy) is to manage a jobs memory placement within its allowed cpuset. However, CPU affinity and NUMA memory placement are managed within the kernel using absolute system wide numbering, not cpuset relative numbering. This is ok until a job is migrated to a different cpuset, or what's the same, a jobs cpuset is moved to different CPUs and Memory Nodes. Then the CPU affinity and NUMA memory placement of the tasks in the job need to be updated, to preserve their cpuset-relative position. This can be done for CPU affinity using sched_setaffinity() from user code, as one task can modify anothers CPU affinity. This cannot be done from an external task for NUMA memory placement, as that can only be modified in the context of the task using it. However, it easy enough to remap a tasks NUMA mempolicy automatically when a task is migrated, using the existing cpuset mechanism to trigger a refresh of a tasks memory placement after its cpuset has changed. All that is needed is the old and new nodemask, and notice to the task that it needs to rebind its mempolicy. The tasks mems_allowed has the old mask, the tasks cpuset has the new mask, and the existing cpuset_update_current_mems_allowed() mechanism provides the notice. The bitmap/cpumask/nodemask remap operators provide the cpuset relative calculations. This patch leaves open a couple of issues: 1) Updating vma and shmfs/tmpfs/hugetlbfs memory policies: These mempolicies may reference nodes outside of those allowed to the current task by its cpuset. Tasks are migrated as part of jobs, which reside on what might be several cpusets in a subtree. When such a job is migrated, all NUMA memory policy references to nodes within that cpuset subtree should be translated, and references to any nodes outside that subtree should be left untouched. A future patch will provide the cpuset mechanism needed to mark such subtrees. With that patch, we will be able to correctly migrate these other memory policies across a job migration. 2) Updating cpuset, affinity and memory policies in user space: This is harder. Any placement state stored in user space using system-wide numbering will be invalidated across a migration. More work will be required to provide user code with a migration-safe means to manage its cpuset relative placement, while preserving the current API's that pass system wide numbers, not cpuset relative numbers across the kernel-user boundary. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpusets: confine pdflush to its cpusetPaul Jackson2005-10-301-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch keeps pdflush daemons on the same cpuset as their parent, the kthread daemon. Some large NUMA configurations put as much as they can of kernel threads and other classic Unix load in what's called a bootcpuset, keeping the rest of the system free for dedicated jobs. This effort is thwarted by pdflush, which dynamically destroys and recreates pdflush daemons depending on load. It's easy enough to force the originally created pdflush deamons into the bootcpuset, at system boottime. But the pdflush threads created later were allowed to run freely across the system, due to the necessary line in their startup kthread(): set_cpus_allowed(current, CPU_MASK_ALL); By simply coding pdflush to start its threads with the cpus_allowed restrictions of its cpuset (inherited from kthread, its parent) we can ensure that dynamically created pdflush threads are also kept in the bootcpuset. On systems w/o cpusets, or w/o a bootcpuset implementation, the following will have no affect, leaving pdflush to run on any CPU, as before. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] ext3: Fix unmapped buffers in transaction's listsJan Kara2005-10-301-10/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the problem (BUG 4964) with unmapped buffers in transaction's t_sync_data list. The problem is we need to call filesystem's own invalidatepage() from block_write_full_page(). block_write_full_page() must call filesystem's invalidatepage(). Otherwise following nasty race can happen: proc 1 proc 2 ------ ------ - write some new data to 'offset' => bh gets to the transactions data list - starts truncate => i_size set to new size - mpage_writepages() - ext3_ordered_writepage() to 'offset' - block_write_full_page() - page->index > end_index+1 - block_invalidatepage() - discard_buffer() - clear_buffer_mapped() - commit triggers and finds unmapped buffer - BOOM! Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm/filemap.c:filemap_populate(): move export.Nikita Danilov2005-10-291-1/+1
| | | | | | | | | move EXPORT_SYMBOL(filemap_populate) to the proper place: just after function itself: it's easy to miss that function is exported otherwise. 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] mm: wider use of for_each_*cpu()John Hawkes2005-10-291-4/+1
| | | | | | | | | | | | In 'mm' change the explicit use of a for-loop using NR_CPUS into the general for_each_cpu() constructs. This widens the scope of potential future optimizations of the general constructs, as well as takes advantage of the existing optimizations of first_cpu() and next_cpu(), which is advantageous when the true CPU count is much smaller than NR_CPUS. Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Remove policy contextualization from mbindChristoph Lameter2005-10-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Policy contextualization is only useful for task based policies and not for vma based policies. It may be useful to define allowed nodes that are not accessible from this thread because other threads may have access to these nodes. Without this patch strange memory policy situations may cause an application to fail with out of memory. Example: Let's say we have two threads A and B that share the same address space and a huge array computational array X. Thread A is restricted by its cpuset to nodes 0 and 1 and thread B is restricted by its cpuset to nodes 2 and 3. Thread A now wants to restrict allocations to the first node and thus applies a BIND policy on X to node 0 and 2. The cpuset limits this to node 0. Thus pages for X must be allocated on node 0 now. Thread B now touches a page that has never been used in X and faults in a page. According to the BIND policy of the vma for X the page must be allocated on page 0. However, the cpuset of B does not allow allocation on 0 and 1. Now the application fails in alloc_pages with out of memory. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Implement sys_* do_* layering in the memory policy layer.Christoph Lameter2005-10-291-114/+162
| | | | | | | | | | | | | | | | | | | - Do a separation between do_xxx and sys_xxx functions. sys_xxx functions take variable sized bitmaps from user space as arguments. do_xxx functions take fixed sized nodemask_t as arguments and may be used from inside the kernel. Doing so simplifies the initialization code. There is no fs = kernel_ds assumption anymore. - Split up get_nodes into get_nodes (which gets the node list) and contextualize_policy which restricts the nodes to those accessible to the task and updates cpusets. - Add comments explaining limitations of bind policy Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] memory hotplug: call setup_per_zone_pages_min after hotplugDave Hansen2005-10-291-0/+2
| | | | | | | | | | | | | | | | | From: IWAMOTO Toshihiro <iwamoto@valinux.co.jp> > I found the tests does not work well with Dave's patchset. > I've found the followings: > > - setup_per_zone_pages_min() calls should be added in > capture_page_range() and online_pages() > - lru_add_drain() should be called before try_to_migrate_pages() The following patch deals with the first item. Signed-off-by: IWAMOTO Toshihiro <iwamoto@valinux.co.jp> 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] memory hotplug: move section_mem_map alloc to sparse.cDave Hansen2005-10-292-50/+72
| | | | | | | | | | | | | | | This basically keeps up from having to extern __kmalloc_section_memmap(). The vaddr_in_vmalloc_area() helper could go in a vmalloc header, but that header gets hard to work with, because it needs some arch-specific macros. Just stick it in here for now, instead of creating another header. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Lion Vollnhals <webmaster@schiggl.de> Signed-off-by: Jiri Slaby <xslaby@fi.muni.cz> Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] memory hotplug: sysfs and add/remove functionsDave Hansen2005-10-294-3/+189
| | | | | | | | | | | | | | | This adds generic memory add/remove and supporting functions for memory hotplug into a new file as well as a memory hotplug kernel config option. Individual architecture patches will follow. For now, disable memory hotplug when swsusp is enabled. There's a lot of churn there right now. We'll fix it up properly once it calms down. Signed-off-by: Matt Tolentino <matthew.e.tolentino@intel.com> 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] memory hotplug locking: zone span seqlockDave Hansen2005-10-291-5/+14
| | | | | | | | | | See the "fixup bad_range()" patch for more information, but this actually creates a the lock to protect things making assumptions about a zone's size staying constant at runtime. 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] memory hotplug locking: node_size_lockDave Hansen2005-10-291-0/+1
| | | | | | | | | | | | | | | | | | | | pgdat->node_size_lock is basically only neeeded in one place in the normal code: show_mem(), which is the arch-specific sysrq-m printing function. Strictly speaking, the architectures not doing memory hotplug do no need this locking in show_mem(). However, they are all included for completeness. This should also make any future consolidation of all of the implementations a little more straightforward. This lock is also held in the sparsemem code during a memory removal, as sections are invalidated. This is the place there pfn_valid() is made false for a memory area that's being removed. The lock is only required when doing pfn_valid() operations on memory which the user does not already have a reference on the page, such as in show_mem(). 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] memory hotplug prep: fixup bad_range()Dave Hansen2005-10-291-5/+21
| | | | | | | | | | | | | | | | When doing memory hotplug operations, the size of existing zones can obviously change. This means that zone->zone_{start_pfn,spanned_pages} can change. There are currently no locks that protect these structure members. However, they are rarely accessed at runtime. Outside of swsusp, the only place that I can find is bad_range(). So, split bad_range() up into two pieces: one that needs to be locked and anther that doesn't. 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] memory hotplug prep: __section_nr helperDave Hansen2005-10-291-0/+25
| | | | | | | | A little helper that we use in the hotplug code. 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] memory hotplug prep: break out zone initializationDave Hansen2005-10-291-40/+58
| | | | | | | | | | | | | If a zone is empty at boot-time and then hot-added to later, it needs to run the same init code that would have been run on it at boot. This patch breaks out zone table and per-cpu-pages functions for use by the hotplug code. You can almost see all of the free_area_init_core() function on one page now. :) 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] .text page fault SMP scalability optimizationAndrea Arcangeli2005-10-291-4/+16
| | | | | | | | | | | | | | | We had a problem on ppc64 where with more than 4 threads a large system wouldn't scale well while faulting in the .text (most of the time was spent in the kernel despite it was an userland compute intensive app). The reason is the useless overwrite of the same pte from all cpu. I fixed it this way (verified on an older kernel but the forward port is almost identical). This will benefit all archs not just ppc64. Signed-off-by: Andrea Arcangeli <andrea@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] hugetlb: demand fault handlerAdam Litke2005-10-291-85/+95
| | | | | | | | | | | | | | Below is a patch to implement demand faulting for huge pages. The main motivation for changing from prefaulting to demand faulting is so that huge page memory areas can be allocated according to NUMA policy. Thanks to consolidated hugetlb code, switching the behavior requires changing only one fault handler. The bulk of the patch just moves the logic from hugelb_prefault() to hugetlb_pte_fault() and find_get_huge_page(). Signed-off-by: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mm: update comments to pte lockHugh Dickins2005-10-293-10/+9
| | | | | | | | Updated several references to page_table_lock in common code comments. 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] mm: fix rss and mmlist lockingHugh Dickins2005-10-292-2/+5
| | | | | | | | | | | | | | | | | | A couple of oddities were guarded by page_table_lock, no longer properly guarded when that is split. The mm_counters of file_rss and anon_rss: make those an atomic_t, or an atomic64_t if the architecture supports it, in such a case. Definitions by courtesy of Christoph Lameter: who spent considerable effort on more scalable ways of counting, but found insufficient benefit in practice. And adding an mm with swap to the mmlist for swapoff: the list is well- guarded by its own lock, but the list_empty check now has to be repeated inside 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] mm: split page table lockHugh Dickins2005-10-2912-48/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Christoph Lameter demonstrated very poor scalability on the SGI 512-way, with a many-threaded application which concurrently initializes different parts of a large anonymous area. This patch corrects that, by using a separate spinlock per page table page, to guard the page table entries in that page, instead of using the mm's single page_table_lock. (But even then, page_table_lock is still used to guard page table allocation, and anon_vma allocation.) In this implementation, the spinlock is tucked inside the struct page of the page table page: with a BUILD_BUG_ON in case it overflows - which it would in the case of 32-bit PA-RISC with spinlock debugging enabled. Splitting the lock is not quite for free: another cacheline access. Ideally, I suppose we would use split ptlock only for multi-threaded processes on multi-cpu machines; but deciding that dynamically would have its own costs. So for now enable it by config, at some number of cpus - since the Kconfig language doesn't support inequalities, let preprocessor compare that with NR_CPUS. But I don't think it's worth being user-configurable: for good testing of both split and unsplit configs, split now at 4 cpus, and perhaps change that to 8 later. There is a benefit even for singly threaded processes: kswapd can be attacking one part of the mm while another part is busy faulting. 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] mm: follow_page with inner ptlockHugh Dickins2005-10-292-82/+73
| | | | | | | | | | | | | | | | | | | | | | | | Final step in pushing down common core's page_table_lock. follow_page no longer wants caller to hold page_table_lock, uses pte_offset_map_lock itself; and so no page_table_lock is taken in get_user_pages itself. But get_user_pages (and get_futex_key) do then need follow_page to pin the page for them: take Daniel's suggestion of bitflags to follow_page. Need one for WRITE, another for TOUCH (it was the accessed flag before: vanished along with check_user_page_readable, but surely get_numa_maps is wrong to mark every page it finds as accessed), another for GET. And another, ANON to dispose of untouched_anonymous_page: it seems silly for that to descend a second time, let follow_page observe if there was no page table and return ZERO_PAGE if so. Fix minor bug in that: check VM_LOCKED - make_pages_present ought to make readonly anonymous present. Give get_numa_maps a cond_resched while we're there. 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] mm: kill check_user_page_readableHugh Dickins2005-10-291-25/+4
| | | | | | | | | | | | | | | | | | | | | | | | | check_user_page_readable is a problematic variant of follow_page. It's used only by oprofile's i386 and arm backtrace code, at interrupt time, to establish whether a userspace stackframe is currently readable. This is problematic, because we want to push the page_table_lock down inside follow_page, and later split it; whereas oprofile is doing a spin_trylock on it (in the i386 case, forgotten in the arm case), and needs that to pin perhaps two pages spanned by the stackframe (which might be covered by different locks when we split). I think oprofile is going about this in the wrong way: it doesn't need to know the area is readable (neither i386 nor arm uses read protection of user pages), it doesn't need to pin the memory, it should simply __copy_from_user_inatomic, and see if that succeeds or not. Sorry, but I've not got around to devising the sparse __user annotations for this. Then we can eliminate check_user_page_readable, and return to a single follow_page without the __follow_page variants. 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] mm: rmap with inner ptlockHugh Dickins2005-10-292-63/+58
| | | | | | | | | | | | | | | rmap's page_check_address descend without page_table_lock. First just pte_offset_map in case there's no pte present worth locking for, then take page_table_lock for the full check, and pass ptl back to caller in the same style as pte_offset_map_lock. __xip_unmap, page_referenced_one and try_to_unmap_one use pte_unmap_unlock. try_to_unmap_cluster also. page_check_address reformatted to avoid progressive indentation. No use is made of its one error code, return NULL when it fails. 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] mm: xip_unmap ZERO_PAGE fixHugh Dickins2005-10-291-1/+2
| | | | | | | | | | Small fix to the PageReserved patch: the mips ZERO_PAGE(address) depends on address, so __xip_unmap is wrong to initialize page with that before address is initialized; and in fact must re-evaluate it each iteration. 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] mm: unmap_vmas with inner ptlockHugh Dickins2005-10-293-44/+17
| | | | | | | | | | | | | | | | | | | | Remove the page_table_lock from around the calls to unmap_vmas, and replace the pte_offset_map in zap_pte_range by pte_offset_map_lock: all callers are now safe to descend without page_table_lock. Don't attempt fancy locking for hugepages, just take page_table_lock in unmap_hugepage_range. Which makes zap_hugepage_range, and the hugetlb test in zap_page_range, redundant: unmap_vmas calls unmap_hugepage_range anyway. Nor does unmap_vmas have much use for its mm arg now. The tlb_start_vma and tlb_end_vma in unmap_page_range are now called without page_table_lock: if they're implemented at all, they typically come down to flush_cache_range (usually done outside page_table_lock) and flush_tlb_range (which we already audited for the mprotect case). 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] mm: unlink vma before pagetablesHugh Dickins2005-10-292-19/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In most places the descent from pgd to pud to pmd to pte holds mmap_sem (exclusively or not), which ensures that free_pgtables cannot be freeing page tables from any level at the same time. But truncation and reverse mapping descend without mmap_sem. No problem: just make sure that a vma is unlinked from its prio_tree (or nonlinear list) and from its anon_vma list, after zapping the vma, but before freeing its page tables. Then neither vmtruncate nor rmap can reach that vma whose page tables are now volatile (nor do they need to reach it, since all its page entries have been zapped by this stage). The i_mmap_lock and anon_vma->lock already serialize this correctly; but the locking hierarchy is such that we cannot take them while holding page_table_lock. Well, we're trying to push that down anyway. So in this patch, move anon_vma_unlink and unlink_file_vma into free_pgtables, at the same time as moving page_table_lock around calls to unmap_vmas. tlb_gather_mmu and tlb_finish_mmu then fall outside the page_table_lock, but we made them preempt_disable and preempt_enable earlier; and a long source audit of all the architectures has shown no problem with removing page_table_lock from them. free_pgtables doesn't need page_table_lock for itself, nor for what it calls; tlb->mm->nr_ptes is usually protected by page_table_lock, but partly by non-exclusive mmap_sem - here it's decremented with exclusive mmap_sem, or mm_users 0. update_hiwater_rss and vm_unacct_memory don't need page_table_lock either. 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] mm: pte_offset_map_lock loopsHugh Dickins2005-10-294-34/+21
| | | | | | | | | | | | | | | | | | | Convert those common loops using page_table_lock on the outside and pte_offset_map within to use just pte_offset_map_lock within instead. These all hold mmap_sem (some exclusively, some not), so at no level can a page table be whipped away from beneath them. But whereas pte_alloc loops tested with the "atomic" pmd_present, these loops are testing with pmd_none, which on i386 PAE tests both lower and upper halves. That's now unsafe, so add a cast into pmd_none to test only the vital lower half: we lose a little sensitivity to a corrupt middle directory, but not enough to worry about. It appears that i386 and UML were the only architectures vulnerable in this way, and pgd and pud no problem. 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] mm: page fault handler lockingHugh Dickins2005-10-291-60/+90
| | | | | | | | | | | | | | | | | | | | | | | | | | | On the page fault path, the patch before last pushed acquiring the page_table_lock down to the head of handle_pte_fault (though it's also taken and dropped earlier when a new page table has to be allocated). Now delete that line, read "entry = *pte" without it, and go off to this or that page fault handler on the basis of this unlocked peek. Usually the handler can proceed without the lock, relying on the subsequent locked pte_same or pte_none test to back out when necessary; though do_wp_page needs the lock immediately, and do_file_page doesn't check (if there's a race, install_page just zaps the entry and reinstalls it). But on those architectures (notably i386 with PAE) whose pte is too big to be read atomically, if SMP or preemption is enabled, do_swap_page and do_file_page might cause irretrievable damage if passed a Frankenstein entry stitched together from unrelated parts. In those configs, "pte_unmap_same" has to take page_table_lock, validate orig_pte still the same, and drop page_table_lock before unmapping, before proceeding. Use pte_offset_map_lock and pte_unmap_unlock throughout the handlers; but lock avoidance leaves more lone maps and unmaps than elsewhere. 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] mm: ptd_alloc take ptlockHugh Dickins2005-10-294-124/+67
| | | | | | | | | | | | | | | | | | | | | | Second step in pushing down the page_table_lock. Remove the temporary bridging hack from __pud_alloc, __pmd_alloc, __pte_alloc: expect callers not to hold page_table_lock, whether it's on init_mm or a user mm; take page_table_lock internally to check if a racing task already allocated. Convert their callers from common code. But avoid coming back to change them again later: instead of moving the spin_lock(&mm->page_table_lock) down, switch over to new macros pte_alloc_map_lock and pte_unmap_unlock, which encapsulate the mapping+locking and unlocking+unmapping together, and in the end may use alternatives to the mm page_table_lock itself. These callers all hold mmap_sem (some exclusively, some not), so at no level can a page table be whipped away from beneath them; and pte_alloc uses the "atomic" pmd_present to test whether it needs to allocate. It appears that on all arches we can safely descend without page_table_lock. 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] mm: ptd_alloc inline and outHugh Dickins2005-10-292-62/+40
| | | | | | | | | | | | | | | | | | | | | It seems odd to me that, whereas pud_alloc and pmd_alloc test inline, only calling out-of-line __pud_alloc __pmd_alloc if allocation needed, pte_alloc_map and pte_alloc_kernel are entirely out-of-line. Though it does add a little to kernel size, change them to macros testing inline, calling __pte_alloc or __pte_alloc_kernel to allocate out-of-line. Mark none of them as fastcalls, leave that to CONFIG_REGPARM or not. It also seems more natural for the out-of-line functions to leave the offset calculation and map to the inline, which has to do it anyway for the common case. At least mremap move wants __pte_alloc without _map. Macros rather than inline functions, certainly to avoid the header file issues which arise from CONFIG_HIGHPTE needing kmap_types.h, but also in case any architectures I haven't built would have other such problems. 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] mm: init_mm without ptlockHugh Dickins2005-10-292-36/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | First step in pushing down the page_table_lock. init_mm.page_table_lock has been used throughout the architectures (usually for ioremap): not to serialize kernel address space allocation (that's usually vmlist_lock), but because pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it. Reverse that: don't lock or unlock init_mm.page_table_lock in any of the architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take and drop it when allocating a new one, to check lest a racing task already did. Similarly no page_table_lock in vmalloc's map_vm_area. Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle user mms, which are converted only by a later patch, for now they have to lock differently according to whether or not it's init_mm. If sources get muddled, there's a danger that an arch source taking init_mm.page_table_lock will be mixed with common source also taking it (or neither take it). So break the rules and make another change, which should break the build for such a mismatch: remove the redundant mm arg from pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13). Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64 used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64 map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free took page_table_lock for no good reason. 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] mm: ia64 use expand_upwardsHugh Dickins2005-10-291-3/+14
| | | | | | | | | | | | | | | ia64 has expand_backing_store function for growing its Register Backing Store vma upwards. But more complete code for this purpose is found in the CONFIG_STACK_GROWSUP part of mm/mmap.c. Uglify its #ifdefs further to provide expand_upwards for ia64 as well as expand_stack for parisc. The Register Backing Store vma should be marked VM_ACCOUNT. Implement the intention of growing it only a page at a time, instead of passing an address outside of the vma to handle_mm_fault, with unknown consequences. 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] mm: update_hiwaters just in timeHugh Dickins2005-10-297-32/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | update_mem_hiwater has attracted various criticisms, in particular from those concerned with mm scalability. Originally it was called whenever rss or total_vm got raised. Then many of those callsites were replaced by a timer tick call from account_system_time. Now Frank van Maarseveen reports that to be found inadequate. How about this? Works for Frank. Replace update_mem_hiwater, a poor combination of two unrelated ops, by macros update_hiwater_rss and update_hiwater_vm. Don't attempt to keep mm->hiwater_rss up to date at timer tick, nor every time we raise rss (usually by 1): those are hot paths. Do the opposite, update only when about to lower rss (usually by many), or just before final accounting in do_exit. Handle mm->hiwater_vm in the same way, though it's much less of an issue. Demand that whoever collects these hiwater statistics do the work of taking the maximum with rss or total_vm. And there has been no collector of these hiwater statistics in the tree. The new convention needs an example, so match Frank's usage by adding a VmPeak line above VmSize to /proc/<pid>/status, and also a VmHWM line above VmRSS (High-Water-Mark or High-Water-Memory). There was a particular anomaly during mremap move, that hiwater_vm might be captured too high. A fleeting such anomaly remains, but it's quickly corrected now, whereas before it would stick. What locking? None: if the app is racy then these statistics will be racy, it's not worth any overhead to make them exact. But whenever it suits, hiwater_vm is updated under exclusive mmap_sem, and hiwater_rss under page_table_lock (for now) or with preemption disabled (later on): without going to any trouble, minimize the time between reading current values and updating, to minimize those occasions when a racing thread bumps a count up and back down in between. 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] mm: zap_pte out of lineHugh Dickins2005-10-291-10/+9
| | | | | | | | | | | There used to be just one call to zap_pte, but it shouldn't be inline now there are two. Check for the common case pte_none before calling, and move its rss accounting up into install_page or install_file_pte - which helps the next patch. 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] mm: do_mremap current mmHugh Dickins2005-10-291-9/+9
| | | | | | | | Cleanup: relieve do_mremap from its surfeit of current->mms. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
generated by cgit (git 2.34.1) at 2024-11-09 19:21:47 +0000