- 20 Oct, 2008 40 commits
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Jim Cromie authored
Adds therm-min/max/crit-alarm callbacks, sensor-device-attribute declarations, and refs to those new decls in the macro used to initialize the therm_group (of sysfs files) The thermistors use voltage channels to measure; so they don't have a fault-alarm, but unlike the other voltages, they do have an overtemp, which we call crit (by convention). [akpm@linux-foundation.org: cleanup] Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jim Cromie authored
temp and vin status register values may be set by chip specifications, set again by bios, or by this previously loaded driver. Debug output nicely displays modprobe init=\d actions. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jim Cromie authored
Driver handles 3 logical devices in fixed length array. Give this a define-d constant. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jim Cromie authored
Adds temp-min/max/crit/fault-alarm callbacks, sensor-device-attribute declarations, and refs to those new decls in the macro used to initialize the temp_group (of sysfs files) [akpm@linux-foundation.org: cleanups] Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jim Cromie authored
Adds vin-min/max-alarm callbacks, sensor-device-attribute declarations, and refs to those new decls in the macro used to initialize the vin_group (of sysfs files) [akpm@linux-foundation.org: cleanups] Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jim Cromie authored
Bring hwmon/pc87360 into agreement with Documentation/hwmon/sysfs-interface. Patchset adds separate limit alarms for voltages and temps, it also adds temp[123]_fault files. On my Soekris, temps 1,2 are unused/unconnected, so temp[123]_fault = 1,1,0 respectively. This agrees with /usr/bin/sensors, which has always shown them as OPEN. Temps 4,5,6 are thermistor based, and dont have a fault bit in their status register. This patch: 2 different kinds of constants added: - CHAN_ALM_* constants for (later) vin, temp alarm callbacks. - CHAN_* conversion constants, used in _init_device, partly for RW1C bits Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ameya Palande authored
Fix for a typo and and replacing incorrect word in the comment. Signed-off-by: Ameya Palande <2ameya@gmail.com> Cc: "Ashok Raj" <ashok.raj@intel.com> Cc: "Shaohua Li" <shaohua.li@intel.com> Cc: "Anil S Keshavamurthy" <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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WANG Cong authored
These comments are useless, remove them. Signed-off-by: WANG Cong <wangcong@zeuux.org> Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Eric Piel authored
On my HP 2510, pressing the (i) button generates an unknown keycode: 0x213b. So here is a patch adding support for it. However, as it seems there is already support for a similar button connected to 0x231b as keycode, I wonder if it could be a typo in the driver? Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net> Cc: Matthew Garrett <mjg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andi Kleen authored
I fell into the trap recently that it only dumps hrtimers instead of all timers. Fix the documentation. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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WANG Cong authored
Fix arch/um/sys-i386/signal.c: In function 'copy_sc_from_user': arch/um/sys-i386/signal.c:182: warning: dereferencing 'void *' pointer arch/um/sys-i386/signal.c:182: error: request for member '_fxsr_env' in something not a structure or union Signed-off-by: WANG Cong <wangcong@zeuux.org> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Huang Weiyi authored
Removed duplicated include file <linux/smp_lock.h> in arch/m68k/bvme6000/rtc.c. Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matt Helsley authored
Describe why we need the freezer subsystem and how to use it in a documentation file. Since the cgroups.txt file is focused on the subsystem-agnostic portions of cgroups make a directory and move the old cgroups.txt file at the same time. Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: containers@lists.linux-foundation.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matt Helsley authored
check_if_frozen() sounds like it should return something when in fact it's just updating the freezer state. Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matt Helsley authored
Rename cgroup freezer states to be less generic to avoid any name collisions while also better describing what each state is. Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matt Helsley authored
Don't let frozen tasks or cgroups change. This means frozen tasks can't leave their current cgroup for another cgroup. It also means that tasks cannot be added to or removed from a cgroup in the FROZEN state. We enforce these rules by checking for frozen tasks and cgroups in the can_attach() function. Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matt Helsley authored
When a system is resumed after a suspend, it will also unfreeze frozen cgroups. This patchs modifies the resume sequence to skip the tasks which are part of a frozen control group. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matt Helsley authored
This patch implements a new freezer subsystem in the control groups framework. It provides a way to stop and resume execution of all tasks in a cgroup by writing in the cgroup filesystem. The freezer subsystem in the container filesystem defines a file named freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. Reading will return the current state. * Examples of usage : # mkdir /containers/freezer # mount -t cgroup -ofreezer freezer /containers # mkdir /containers/0 # echo $some_pid > /containers/0/tasks to get status of the freezer subsystem : # cat /containers/0/freezer.state RUNNING to freeze all tasks in the container : # echo FROZEN > /containers/0/freezer.state # cat /containers/0/freezer.state FREEZING # cat /containers/0/freezer.state FROZEN to unfreeze all tasks in the container : # echo RUNNING > /containers/0/freezer.state # cat /containers/0/freezer.state RUNNING This is the basic mechanism which should do the right thing for user space task in a simple scenario. It's important to note that freezing can be incomplete. In that case we return EBUSY. This means that some tasks in the cgroup are busy doing something that prevents us from completely freezing the cgroup at this time. After EBUSY, the cgroup will remain partially frozen -- reflected by freezer.state reporting "FREEZING" when read. The state will remain "FREEZING" until one of these things happens: 1) Userspace cancels the freezing operation by writing "RUNNING" to the freezer.state file 2) Userspace retries the freezing operation by writing "FROZEN" to the freezer.state file (writing "FREEZING" is not legal and returns EIO) 3) The tasks that blocked the cgroup from entering the "FROZEN" state disappear from the cgroup's set of tasks. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: export thaw_process] Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matt Helsley authored
Now that the TIF_FREEZE flag is available in all architectures, extract the refrigerator() and freeze_task() from kernel/power/process.c and make it available to all. The refrigerator() can now be used in a control group subsystem implementing a control group freezer. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Matt Helsley <matthltc@us.ibm.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matt Helsley authored
This patch series introduces a cgroup subsystem that utilizes the swsusp freezer to freeze a group of tasks. It's immediately useful for batch job management scripts. It should also be useful in the future for implementing container checkpoint/restart. The freezer subsystem in the container filesystem defines a cgroup file named freezer.state. Reading freezer.state will return the current state of the cgroup. Writing "FROZEN" to the state file will freeze all tasks in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. * Examples of usage : # mkdir /containers/freezer # mount -t cgroup -ofreezer freezer /containers # mkdir /containers/0 # echo $some_pid > /containers/0/tasks to get status of the freezer subsystem : # cat /containers/0/freezer.state RUNNING to freeze all tasks in the container : # echo FROZEN > /containers/0/freezer.state # cat /containers/0/freezer.state FREEZING # cat /containers/0/freezer.state FROZEN to unfreeze all tasks in the container : # echo RUNNING > /containers/0/freezer.state # cat /containers/0/freezer.state RUNNING This patch: The first step in making the refrigerator() available to all architectures, even for those without power management. The purpose of such a change is to be able to use the refrigerator() in a new control group subsystem which will implement a control group freezer. [akpm@linux-foundation.org: fix sparc] Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Pavel Machek <pavel@suse.cz> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Nigel Cunningham <nigel@tuxonice.net> Tested-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Brice Goglin authored
To prepare the chunking, move the sys_move_pages() code that is used when nodes!=NULL into do_pages_move(). And rename do_move_pages() into do_move_page_to_node_array(). Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Brice Goglin authored
do_pages_stat() does not need any page_to_node entry for real. Just pass the pointers to the user-space page address array and to the user-space status array, and have do_pages_stat() traverse the former and fill the latter directly. Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Brice Goglin authored
A patchset reworking sys_move_pages(). It removes the possibly large vmalloc by using multiple chunks when migrating large buffers. It also dramatically increases the throughput for large buffers since the lookup in new_page_node() is now limited to a single chunk, causing the quadratic complexity to have a much slower impact. There is no need to use any radix-tree-like structure to improve this lookup. sys_move_pages() duration on a 4-quadcore-opteron 2347HE (1.9Gz), migrating between nodes #2 and #3: length move_pages (us) move_pages+patch (us) 4kB 126 98 40kB 198 168 400kB 963 937 4MB 12503 11930 40MB 246867 11848 Patches #1 and #4 are the important ones: 1) stop returning -ENOENT from sys_move_pages() if nothing got migrated 2) don't vmalloc a huge page_to_node array for do_pages_stat() 3) extract do_pages_move() out of sys_move_pages() 4) rework do_pages_move() to work on page_sized chunks 5) move_pages: no need to set pp->page to ZERO_PAGE(0) by default This patch: There is no point in returning -ENOENT from sys_move_pages() if all pages were already on the right node, while we return 0 if only 1 page was not. Most application don't know where their pages are allocated, so it's not an error to try to migrate them anyway. Just return 0 and let the status array in user-space be checked if the application needs details. It will make the upcoming chunked-move_pages() support much easier. Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nathan Fontenot authored
During hotplug memory remove, memory regions should be released on a PAGES_PER_SECTION size chunks. This mirrors the code in add_memory where resources are requested on a PAGES_PER_SECTION size. Attempting to release the entire memory region fails because there is not a single resource for the total number of pages being removed. Instead the resources for the pages are split in PAGES_PER_SECTION size chunks as requested during memory add. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andrea Righi authored
The current documentation of dirty_ratio and dirty_background_ratio is a bit misleading. In the documentation we say that they are "a percentage of total system memory", but the current page writeback policy, intead, is to apply the percentages to the dirtyable memory, that means free pages + reclaimable pages. Better to be more explicit to clarify this concept. Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Shaohua Li authored
This attribute just has a write operation. [akpm@linux-foundation.org: use S_IWUSR as suggested by Randy] Signed-off-by: Shaohua Li <shaohua.li@intel.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Gerald Schaefer authored
This replaces zone->lru_lock in setup_per_zone_pages_min() with zone->lock. There seems to be no need for the lru_lock anymore, but there is a need for zone->lock instead, because that function may call move_freepages() via setup_zone_migrate_reserve(). Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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KOSAKI Motohiro authored
Presently hugepage doesn't use zero page at all because zero page is only used for coredumping and hugepage can't core dump. However we have now implemented hugepage coredumping. Therefore we should implement the zero page of hugepage. Implementation note: o Why do we only check VM_SHARED for zero page? normal page checked as .. static inline int use_zero_page(struct vm_area_struct *vma) { if (vma->vm_flags & (VM_LOCKED | VM_SHARED)) return 0; return !vma->vm_ops || !vma->vm_ops->fault; } First, hugepages are never mlock()ed. We aren't concerned with VM_LOCKED. Second, hugetlbfs is a pseudo filesystem, not a real filesystem and it doesn't have any file backing. Thus ops->fault checking is meaningless. o Why don't we use zero page if !pte. !pte indicate {pud, pmd} doesn't exist or some error happened. So we shouldn't return zero page if any error occurred. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Adam Litke <agl@us.ibm.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Kawai Hidehiro <hidehiro.kawai.ez@hitachi.com> Cc: Mel Gorman <mel@skynet.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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KOSAKI Motohiro authored
Presently hugepage's vma has a VM_RESERVED flag in order not to be swapped. But a VM_RESERVED vma isn't core dumped because this flag is often used for some kernel vmas (e.g. vmalloc, sound related). Thus hugepages are never dumped and it can't be debugged easily. Many developers want hugepages to be included into core-dump. However, We can't read generic VM_RESERVED area because this area is often IO mapping area. then these area reading may change device state. it is definitly undesiable side-effect. So adding a hugepage specific bit to the coredump filter is better. It will be able to hugepage core dumping and doesn't cause any side-effect to any i/o devices. In additional, libhugetlb use hugetlb private mapping pages as anonymous page. Then, hugepage private mapping pages should be core dumped by default. Then, /proc/[pid]/core_dump_filter has two new bits. - bit 5 mean hugetlb private mapping pages are dumped or not. (default: yes) - bit 6 mean hugetlb shared mapping pages are dumped or not. (default: no) I tested by following method. % ulimit -c unlimited % ./crash_hugepage 50 % ./crash_hugepage 50 -p % ls -lh % gdb ./crash_hugepage core % % echo 0x43 > /proc/self/coredump_filter % ./crash_hugepage 50 % ./crash_hugepage 50 -p % ls -lh % gdb ./crash_hugepage core #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <sys/mman.h> #include <string.h> #include "hugetlbfs.h" int main(int argc, char** argv){ char* p; int ch; int mmap_flags = MAP_SHARED; int fd; int nr_pages; while((ch = getopt(argc, argv, "p")) != -1) { switch (ch) { case 'p': mmap_flags &= ~MAP_SHARED; mmap_flags |= MAP_PRIVATE; break; default: /* nothing*/ break; } } argc -= optind; argv += optind; if (argc == 0){ printf("need # of pages\n"); exit(1); } nr_pages = atoi(argv[0]); if (nr_pages < 2) { printf("nr_pages must >2\n"); exit(1); } fd = hugetlbfs_unlinked_fd(); p = mmap(NULL, nr_pages * gethugepagesize(), PROT_READ|PROT_WRITE, mmap_flags, fd, 0); sleep(2); *(p + gethugepagesize()) = 1; /* COW */ sleep(2); /* crash! */ *(int*)0 = 1; return 0; } Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Kawai Hidehiro <hidehiro.kawai.ez@hitachi.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: William Irwin <wli@holomorphy.com> Cc: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Yinghai Lu authored
Improve debuggability of memory setup problems. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Harvey Harrison authored
mm/hugetlb.c:265:17: warning: symbol 'resv_map_alloc' was not declared. Should it be static? mm/hugetlb.c:277:6: warning: symbol 'resv_map_release' was not declared. Should it be static? mm/hugetlb.c:292:9: warning: Using plain integer as NULL pointer mm/hugetlb.c:1750:5: warning: symbol 'unmap_ref_private' was not declared. Should it be static? Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nick Piggin authored
Rewrite the vmap allocator to use rbtrees and lazy tlb flushing, and provide a fast, scalable percpu frontend for small vmaps (requires a slightly different API, though). The biggest problem with vmap is actually vunmap. Presently this requires a global kernel TLB flush, which on most architectures is a broadcast IPI to all CPUs to flush the cache. This is all done under a global lock. As the number of CPUs increases, so will the number of vunmaps a scaled workload will want to perform, and so will the cost of a global TLB flush. This gives terrible quadratic scalability characteristics. Another problem is that the entire vmap subsystem works under a single lock. It is a rwlock, but it is actually taken for write in all the fast paths, and the read locking would likely never be run concurrently anyway, so it's just pointless. This is a rewrite of vmap subsystem to solve those problems. The existing vmalloc API is implemented on top of the rewritten subsystem. The TLB flushing problem is solved by using lazy TLB unmapping. vmap addresses do not have to be flushed immediately when they are vunmapped, because the kernel will not reuse them again (would be a use-after-free) until they are reallocated. So the addresses aren't allocated again until a subsequent TLB flush. A single TLB flush then can flush multiple vunmaps from each CPU. XEN and PAT and such do not like deferred TLB flushing because they can't always handle multiple aliasing virtual addresses to a physical address. They now call vm_unmap_aliases() in order to flush any deferred mappings. That call is very expensive (well, actually not a lot more expensive than a single vunmap under the old scheme), however it should be OK if not called too often. The virtual memory extent information is stored in an rbtree rather than a linked list to improve the algorithmic scalability. There is a per-CPU allocator for small vmaps, which amortizes or avoids global locking. To use the per-CPU interface, the vm_map_ram / vm_unmap_ram interfaces must be used in place of vmap and vunmap. Vmalloc does not use these interfaces at the moment, so it will not be quite so scalable (although it will use lazy TLB flushing). As a quick test of performance, I ran a test that loops in the kernel, linearly mapping then touching then unmapping 4 pages. Different numbers of tests were run in parallel on an 4 core, 2 socket opteron. Results are in nanoseconds per map+touch+unmap. threads vanilla vmap rewrite 1 14700 2900 2 33600 3000 4 49500 2800 8 70631 2900 So with a 8 cores, the rewritten version is already 25x faster. In a slightly more realistic test (although with an older and less scalable version of the patch), I ripped the not-very-good vunmap batching code out of XFS, and implemented the large buffer mapping with vm_map_ram and vm_unmap_ram... along with a couple of other tricks, I was able to speed up a large directory workload by 20x on a 64 CPU system. I believe vmap/vunmap is actually sped up a lot more than 20x on such a system, but I'm running into other locks now. vmap is pretty well blown off the profiles. Before: 1352059 total 0.1401 798784 _write_lock 8320.6667 <- vmlist_lock 529313 default_idle 1181.5022 15242 smp_call_function 15.8771 <- vmap tlb flushing 2472 __get_vm_area_node 1.9312 <- vmap 1762 remove_vm_area 4.5885 <- vunmap 316 map_vm_area 0.2297 <- vmap 312 kfree 0.1950 300 _spin_lock 3.1250 252 sn_send_IPI_phys 0.4375 <- tlb flushing 238 vmap 0.8264 <- vmap 216 find_lock_page 0.5192 196 find_next_bit 0.3603 136 sn2_send_IPI 0.2024 130 pio_phys_write_mmr 2.0312 118 unmap_kernel_range 0.1229 After: 78406 total 0.0081 40053 default_idle 89.4040 33576 ia64_spinlock_contention 349.7500 1650 _spin_lock 17.1875 319 __reg_op 0.5538 281 _atomic_dec_and_lock 1.0977 153 mutex_unlock 1.5938 123 iget_locked 0.1671 117 xfs_dir_lookup 0.1662 117 dput 0.1406 114 xfs_iget_core 0.0268 92 xfs_da_hashname 0.1917 75 d_alloc 0.0670 68 vmap_page_range 0.0462 <- vmap 58 kmem_cache_alloc 0.0604 57 memset 0.0540 52 rb_next 0.1625 50 __copy_user 0.0208 49 bitmap_find_free_region 0.2188 <- vmap 46 ia64_sn_udelay 0.1106 45 find_inode_fast 0.1406 42 memcmp 0.2188 42 finish_task_switch 0.1094 42 __d_lookup 0.0410 40 radix_tree_lookup_slot 0.1250 37 _spin_unlock_irqrestore 0.3854 36 xfs_bmapi 0.0050 36 kmem_cache_free 0.0256 35 xfs_vn_getattr 0.0322 34 radix_tree_lookup 0.1062 33 __link_path_walk 0.0035 31 xfs_da_do_buf 0.0091 30 _xfs_buf_find 0.0204 28 find_get_page 0.0875 27 xfs_iread 0.0241 27 __strncpy_from_user 0.2812 26 _xfs_buf_initialize 0.0406 24 _xfs_buf_lookup_pages 0.0179 24 vunmap_page_range 0.0250 <- vunmap 23 find_lock_page 0.0799 22 vm_map_ram 0.0087 <- vmap 20 kfree 0.0125 19 put_page 0.0330 18 __kmalloc 0.0176 17 xfs_da_node_lookup_int 0.0086 17 _read_lock 0.0885 17 page_waitqueue 0.0664 vmap has gone from being the top 5 on the profiles and flushing the crap out of all TLBs, to using less than 1% of kernel time. [akpm@linux-foundation.org: cleanups, section fix] [akpm@linux-foundation.org: fix build on alpha] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Denys Vlasenko authored
__vma_link_file and expand_downwards functions are not small, yeat they are marked inline. They probably had one callsite sometime in the past, but now they have more. In order to prevent similar thing, I also deinlined expand_upwards, despite it having only pne callsite. Nowadays gcc auto-inlines such static functions anyway. In find_extend_vma, I removed one extra level of indirection. Patch is deliberately generated with -U $BIGNUM to make it easier to see that functions are big. Result: # size */*/mmap.o */vmlinux text data bss dec hex filename 9514 188 16 9718 25f6 0.org/mm/mmap.o 9237 188 16 9441 24e1 deinline/mm/mmap.o 6124402 858996 389480 7372878 70804e 0.org/vmlinux 6124113 858996 389480 7372589 707f2d deinline/vmlinux Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nick Piggin authored
trylock_buffer and unlock_buffer open and close a critical section. Hence, we can use the lock bitops to get the desired memory ordering. 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>
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Nick Piggin authored
trylock_page, unlock_page open and close a critical section. Hence, we can use the lock bitops to get the desired memory ordering. Also, mark trylock as likely to succeed (and remove the annotation from callers). 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>
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Nick Piggin authored
unlock_page is fairly expensive. It can be avoided in page reclaim success path. By definition if we have any other references to the page it would be a bug anyway. Signed-off-by: Nick Piggin <npiggin@suse.de> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nick Piggin authored
Setting and clearing the page locked when inserting it into swapcache / pagecache when it has no other references can use non-atomic page flags operations because no other CPU may be operating on it at this time. This saves one atomic operation when inserting a page into pagecache. 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>
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Lee Schermerhorn authored
Rework Posix error return for mlock(). Posix requires error code for mlock*() system calls for some conditions that differ from what kernel low level functions, such as get_user_pages(), return for those conditions. For more info, see: http://marc.info/?l=linux-kernel&m=121750892930775&w=2 This patch provides the same translation of get_user_pages() error codes to posix specified error codes in the context of the mlock rework for unevictable lru. [akpm@linux-foundation.org: fix build] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Lee Schermerhorn authored
This change is intended to make mlock() error returns correct. make_page_present() is a lower level function used by more than mlock(). Subsequent patch[es] will add this error return fixup in an mlock specific path. Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Johannes Weiner authored
During each reclaim scan we accumulate scan pressure on unrelated lists which will result in bogus scans and unwanted reclaims eventually. Scanning lists with few reclaim candidates results in a lot of rotation and therefor also disturbs the list balancing, putting even more pressure on the wrong lists. In a test-case with much streaming IO, and therefor a crowded inactive file page list, swapping started because a) anon pages were reclaimed after swap_cluster_max reclaim invocations -- nr_scan of this list has just accumulated b) active file pages were scanned because *their* nr_scan has also accumulated through the same logic. And this in return created a lot of rotation for file pages and resulted in a decrease of file list priority, again increasing the pressure on anon pages. The result was an evicted working set of anon pages while there were tons of inactive file pages that should have been taken instead. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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