- 16 Jun, 2011 40 commits
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Maxin B. John authored
Instead of listing the architectures that are supported by kmemleak in Documentation/kmemleak.txt, just refer people to the list of supported architecutures in lib/Kconfig.debug so that Documentation/kmemleak.txt does not need more updates for this. Signed-off-by:
Maxin B. John <maxin.john@gmail.com> Signed-off-by:
Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Andrew Murray authored
This patch updates the incomplete documentation concerning the printk extended format specifiers. Signed-off-by:
Andrew Murray <amurray@mpc-data.co.uk> Signed-off-by:
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Linus Torvalds authored
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Check if lowest_mask is initialized in find_lowest_rq() sched: Fix need_resched() when checking peempt
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Dan Rosenberg authored
Fix several security issues in Alpha-specific syscalls. Untested, but mostly trivial. 1. Signedness issue in osf_getdomainname allows copying out-of-bounds kernel memory to userland. 2. Signedness issue in osf_sysinfo allows copying large amounts of kernel memory to userland. 3. Typo (?) in osf_getsysinfo bounds minimum instead of maximum copy size, allowing copying large amounts of kernel memory to userland. 4. Usage of user pointer in osf_wait4 while under KERNEL_DS allows privilege escalation via writing return value of sys_wait4 to kernel memory. Signed-off-by:
Dan Rosenberg <drosenberg@vsecurity.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Geert Uytterhoeven authored
Fixes this warning: drivers/misc/apds990x.c: At top level: drivers/misc/apds990x.c:613: warning: `apds990x_chip_on' defined but not used Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Cc: Samu Onkalo <samu.p.onkalo@nokia.com> Cc: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by:
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Hugh Dickins authored
Andrea Righi reported a case where an exiting task can race against ksmd::scan_get_next_rmap_item (http://lkml.org/lkml/2011/6/1/742) easily triggering a NULL pointer dereference in ksmd. ksm_scan.mm_slot == &ksm_mm_head with only one registered mm CPU 1 (__ksm_exit) CPU 2 (scan_get_next_rmap_item) list_empty() is false lock slot == &ksm_mm_head list_del(slot->mm_list) (list now empty) unlock lock slot = list_entry(slot->mm_list.next) (list is empty, so slot is still ksm_mm_head) unlock slot->mm == NULL ... Oops Close this race by revalidating that the new slot is not simply the list head again. Andrea's test case: #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> #define BUFSIZE getpagesize() int main(int argc, char **argv) { void *ptr; if (posix_memalign(&ptr, getpagesize(), BUFSIZE) < 0) { perror("posix_memalign"); exit(1); } if (madvise(ptr, BUFSIZE, MADV_MERGEABLE) < 0) { perror("madvise"); exit(1); } *(char *)NULL = 0; return 0; } Reported-by:
Andrea Righi <andrea@betterlinux.com> Tested-by:
Hugh Dickins <hughd@google.com> Signed-off-by:
Chris Wright <chrisw@sous-sol.org> Cc: <stable@kernel.org> Signed-off-by:
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Wanlong Gao authored
RTC_CLASS is changed to bool, so 'm' is invalid. Signed-off-by:
Wanlong Gao <wanlong.gao@gmail.com> Acked-by:
Mike Frysinger <vapier@gentoo.org> Acked-by:
Wolfram Sang <w.sang@pengutronix.de> Acked-by:
Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Acked-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by:
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Alexander Stein authored
If dmi_get_system_info() returns NULL, pch_uart_init_port() will dereferencea a zero pointer. This oops was observed on an Atom based board which has no BIOS, but a bootloder which doesn't provide DMI data. Signed-off-by:
Alexander Stein <alexander.stein@systec-electronic.com> Cc: Greg KH <gregkh@suse.de> Cc: <stable@kernel.org> Signed-off-by:
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Nils Carlson authored
When interrupts are delayed due to interrupt masking or due to other interrupts being serviced the HPET periodic-emuation would fail. This happened because given an interval t and a time for the current interrupt m we would compute the next time as t + m. This works until we are delayed for > t, in which case we would be writing a new value which is in fact in the past. This can be solved by computing the next time instead as (k * t) + m where k is large enough to be in the future. The exact computation of k is described in a comment to the code. More detail: Assuming an interval of 5 between each expected interrupt we have a normal case of t0: interrupt, read t0 from comparator, set next interrupt t0 + 5 t5: interrupt, read t5 from comparator, set next interrupt t5 + 5 t10: interrupt, read t10 from comparator, set next interrupt t10 + 5 ... So, what happens when the interrupt is serviced too late? t0: interrupt, read t0 from comparator, set next interrupt t0 + 5 t11: delayed interrupt serviced, read t5 from comparator, set next interrupt t5 + 5, which is in the past! ... counter loops ... t10: Much much later, get the next interrupt. This can happen either because we have interrupts masked for too long (some stupid driver goes on a printk rampage) or just because we are pushing the limits of the interval (too small a period), or both most probably. My solution is to read the main counter as well and set the next interrupt to occur at the right interval, for example: t0: interrupt, read t0 from comparator, set next interrupt t0 + 5 t11: delayed interrupt serviced, read t5 from comparator, set next interrupt t15 as t10 has been missed. t15: back on track. Signed-off-by:
Nils Carlson <nils.carlson@ericsson.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Clemens Ladisch <clemens@ladisch.de> Signed-off-by:
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akpm@linux-foundation.org authored
Commit a77aea92 ("cgroup: remove the ns_cgroup") removed the ns_cgroup but it forgot to remove the related doc in feature-removal-schedule.txt. Signed-off-by:
WANG Cong <xiyou.wangcong@gmail.com> Cc: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Serge E. Hallyn <serge.hallyn@canonical.com> Signed-off-by:
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Mel Gorman authored
Asynchronous compaction is used when promoting to huge pages. This is all very nice but if there are a number of processes in compacting memory, a large number of pages can be isolated. An "asynchronous" process can stall for long periods of time as a result with a user reporting that firefox can stall for 10s of seconds. This patch aborts asynchronous compaction if too many pages are isolated as it's better to fail a hugepage promotion than stall a process. [minchan.kim@gmail.com: return COMPACT_PARTIAL for abort] Reported-and-tested-by:
Ury Stankevich <urykhy@gmail.com> Signed-off-by:
Mel Gorman <mgorman@suse.de> Reviewed-by:
Minchan Kim <minchan.kim@gmail.com> Reviewed-by:
Michal Hocko <mhocko@suse.cz> Signed-off-by:
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Andrea Arcangeli authored
It is unsafe to run page_count during the physical pfn scan because compound_head could trip on a dangling pointer when reading page->first_page if the compound page is being freed by another CPU. [mgorman@suse.de: split out patch] Signed-off-by:
Andrea Arcangeli <aarcange@redhat.com> Signed-off-by:
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Mel Gorman authored
Compaction works with two scanners, a migration and a free scanner. When the scanners crossover, migration within the zone is complete. The location of the scanner is recorded on each cycle to avoid excesive scanning. When a zone is small and mostly reserved, it's very easy for the migration scanner to be close to the end of the zone. Then the following situation can occurs o migration scanner isolates some pages near the end of the zone o free scanner starts at the end of the zone but finds that the migration scanner is already there o free scanner gets reinitialised for the next cycle as cc->migrate_pfn + pageblock_nr_pages moving the free scanner into the next zone o migration scanner moves into the next zone When this happens, NR_ISOLATED accounting goes haywire because some of the accounting happens against the wrong zone. One zones counter remains positive while the other goes negative even though the overall global count is accurate. This was reported on X86-32 with !SMP because !SMP allows the negative counters to be visible. The fact that it is the bug should theoritically be possible there. Signed-off-by: -
Shaohua Li authored
fragmentation_index() returns -1000 when the allocation might succeed This doesn't match the comment and code in compaction_suitable(). I thought compaction_suitable should return COMPACT_PARTIAL in -1000 case, because in this case allocation could succeed depending on watermarks. The impact of this is that compaction starts and compact_finished() is called which rechecks the watermarks and the free lists. It should have the same result in that compaction should not start but is more expensive. Acked-by:
Mel Gorman <mel@csn.ul.ie> Signed-off-by:
Shaohua Li <shaohua.li@intel.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by:
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Minchan Kim authored
Pages isolated for migration are accounted with the vmstat counters NR_ISOLATE_[ANON|FILE]. Callers of migrate_pages() are expected to increment these counters when pages are isolated from the LRU. Once the pages have been migrated, they are put back on the LRU or freed and the isolated count is decremented. Memory failure is not properly accounting for pages it isolates causing the NR_ISOLATED counters to be negative. On SMP builds, this goes unnoticed as negative counters are treated as 0 due to expected per-cpu drift. On UP builds, the counter is treated by too_many_isolated() as a large value causing processes to enter D state during page reclaim or compaction. This patch accounts for pages isolated by memory failure correctly. [mel@csn.ul.ie: rewrote changelog] Reviewed-by:
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Josh Triplett authored
CONFIG_CONSTRUCTORS controls support for running constructor functions at kernel init time. According to commit b99b87f7 ("kernel: constructor support"), gcov (CONFIG_GCOV_KERNEL) needs this. However, CONFIG_CONSTRUCTORS currently defaults to y, with no option to disable it, and CONFIG_GCOV_KERNEL depends on it. Instead, default it to n and have CONFIG_GCOV_KERNEL select it, so that the normal case of CONFIG_GCOV_KERNEL=n will result in CONFIG_CONSTRUCTORS=n. Observed in the short list of =y values in a minimal kernel configuration. Signed-off-by:
Josh Triplett <josh@joshtriplett.org> Acked-by:
Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by:
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Jean Delvare authored
I shall maintain the legacy eeprom driver, until we finally get rid of it. Signed-off-by:
Jean Delvare <khali@linux-fr.org> Signed-off-by:
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KAMEZAWA Hiroyuki authored
Based on Michal Hocko's comment. We are not draining per cpu cached charges during soft limit reclaim because background reclaim doesn't care about charges. It tries to free some memory and charges will not give any. Cached charges might influence only selection of the biggest soft limit offender but as the call is done only after the selection has been already done it makes no change. Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by:
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KAMEZAWA Hiroyuki authored
For performance, memory cgroup caches some "charge" from res_counter into per cpu cache. This works well but because it's cache, it needs to be flushed in some cases. Typical cases are 1. when someone hit limit. 2. when rmdir() is called and need to charges to be 0. But "1" has problem. Recently, with large SMP machines, we see many kworker runs because of flushing memcg's cache. Bad things in implementation are that even if a cpu contains a cache for memcg not related to a memcg which hits limit, drain code is called. This patch does A) check percpu cache contains a useful data or not. B) check other asynchronous percpu draining doesn't run. C) don't call local cpu callback. (*)This patch avoid changing the calling condition with hard-limit. When I run "cat 1Gfile > /dev/null" under 300M limit memcg, [Before] 13767 kamezawa 20 0 98.6m 424 416 D 10.0 0.0 0:00.61 cat 58 root 20 0 0 0 0 S 0.6 0.0 0:00.09 kworker/2:1 60 root 20 0 0 0 0 S 0.6 0.0 0:00.08 kworker/4:1 4 root 20 0 0 0 0 S 0.3 0.0 0:00.02 kworker/0:0 57 root 20 0 0 0 0 S 0.3 0.0 0:00.05 kworker/1:1 61 root 20 0 0 0 0 S 0.3 0.0 0:00.05 kworker/5:1 62 root 20 0 0 0 0 S 0.3 0.0 0:00.05 kworker/6:1 63 root 20 0 0 0 0 S 0.3 0.0 0:00.05 kworker/7:1 [After] 2676 root 20 0 98.6m 416 416 D 9.3 0.0 0:00.87 cat 2626 kamezawa 20 0 15192 1312 920 R 0.3 0.0 0:00.28 top 1 root 20 0 19384 1496 1204 S 0.0 0.0 0:00.66 init 2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd 3 root 20 0 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0 4 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0 [akpm@linux-foundation.org: make percpu_charge_mutex static, tweak comments] Signed-off-by:Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by:
Ying Han <yinghan@google.com> Signed-off-by:
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KAMEZAWA Hiroyuki authored
Hierarchical reclaim doesn't swap out if memsw and resource limits are thye same (memsw_is_minimum == true) because we would hit mem+swap limit anyway (during hard limit reclaim). If it comes to the soft limit we shouldn't consider memsw_is_minimum at all because it doesn't make much sense. Either the soft limit is bellow the hard limit and then we cannot hit mem+swap limit or the direct reclaim takes a precedence. Signed-off-by:
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KAMEZAWA Hiroyuki authored
The following crash was reported: > Call Trace: > [<ffffffff81139792>] mem_cgroup_from_task+0x15/0x17 > [<ffffffff8113a75a>] __mem_cgroup_try_charge+0x148/0x4b4 > [<ffffffff810493f3>] ? need_resched+0x23/0x2d > [<ffffffff814cbf43>] ? preempt_schedule+0x46/0x4f > [<ffffffff8113afe8>] mem_cgroup_charge_common+0x9a/0xce > [<ffffffff8113b6d1>] mem_cgroup_newpage_charge+0x5d/0x5f > [<ffffffff81134024>] khugepaged+0x5da/0xfaf > [<ffffffff81078ea0>] ? __init_waitqueue_head+0x4b/0x4b > [<ffffffff81133a4a>] ? add_mm_counter.constprop.5+0x13/0x13 > [<ffffffff81078625>] kthread+0xa8/0xb0 > [<ffffffff814d13e8>] ? sub_preempt_count+0xa1/0xb4 > [<ffffffff814d5664>] kernel_thread_helper+0x4/0x10 > [<ffffffff814ce858>] ? retint_restore_args+0x13/0x13 > [<ffffffff8107857d>] ? __init_kthread_worker+0x5a/0x5a What happens is that khugepaged tries to charge a huge page against an mm whose last possible owner has already exited, and the memory controller crashes when the stale mm->owner is used to look up the cgroup to charge. mm->owner has never been set to NULL with the last owner going away, but nobody cared until khugepaged came along. Even then it wasn't a problem because the final mmput() on an mm was forced to acquire and release mmap_sem in write-mode, preventing an exiting owner to go away while the mmap_sem was held, and until "692e0b35 mm: thp: optimize memcg charge in khugepaged", the memory cgroup charge was protected by mmap_sem in read-mode. Instead of going back to relying on the mmap_sem to enforce lifetime of a task, this patch ensures that mm->owner is properly set to NULL when the last possible owner is exiting, which the memory controller can handle just fine. [akpm@linux-foundation.org: tweak comments] Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Reported-by:
Dave Jones <davej@redhat.com> Reviewed-by:
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KAMEZAWA Hiroyuki authored
Commit 21a3c964 ("memcg: allocate memory cgroup structures in local nodes") makes page_cgroup allocation as NUMA aware. But that caused a problem https://bugzilla.kernel.org/show_bug.cgi?id=36192. The problem was getting a NID from invalid struct pages, which was not initialized because it was out-of-node, out of [node_start_pfn, node_end_pfn) Now, with sparsemem, page_cgroup_init scans pfn from 0 to max_pfn. But this may scan a pfn which is not on any node and can access memmap which is not initialized. This makes page_cgroup_init() for SPARSEMEM node aware and remove a code to get nid from page->flags. (Then, we'll use valid NID always.) [akpm@linux-foundation.org: try to fix up comments] Signed-off-by:
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KAMEZAWA Hiroyuki authored
Commit 406eb0c9 ("memcg: add memory.numastat api for numa statistics") adds memory.numa_stat file for memory cgroup. But the file permissions are wrong. [kamezawa@bluextal linux-2.6]$ ls -l /cgroup/memory/A/memory.numa_stat ---------- 1 root root 0 Jun 9 18:36 /cgroup/memory/A/memory.numa_stat This patch fixes the permission as [root@bluextal kamezawa]# ls -l /cgroup/memory/A/memory.numa_stat -r--r--r-- 1 root root 0 Jun 10 16:49 /cgroup/memory/A/memory.numa_stat Signed-off-by:
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Eric Miao authored
Seems when a config option does not have a dependency of the menuconfig, it messes the display of the rest configs, even if it's a hidden one. Signed-off-by:
Eric Miao <eric.y.miao@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
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Rafael Aquini authored
When 1GB hugepages are allocated on a system, free(1) reports less available memory than what really is installed in the box. Also, if the total size of hugepages allocated on a system is over half of the total memory size, CommitLimit becomes a negative number. The problem is that gigantic hugepages (order > MAX_ORDER) can only be allocated at boot with bootmem, thus its frames are not accounted to 'totalram_pages'. However, they are accounted to hugetlb_total_pages() What happens to turn CommitLimit into a negative number is this calculation, in fs/proc/meminfo.c: allowed = ((totalram_pages - hugetlb_total_pages()) * sysctl_overcommit_ratio / 100) + total_swap_pages; A similar calculation occurs in __vm_enough_memory() in mm/mmap.c. Also, every vm statistic which depends on 'totalram_pages' will render confusing values, as if system were 'missing' some part of its memory. Impact of this bug: When gigantic hugepages are allocated and sysctl_overcommit_memory == OVERCOMMIT_NEVER. In a such situation, __vm_enough_memory() goes through the mentioned 'allowed' calculation and might end up mistakenly returning -ENOMEM, thus forcing the system to start reclaiming pages earlier than it would be ususal, and this could cause detrimental impact to overall system's performance, depending on the workload. Besides the aforementioned scenario, I can only think of this causing annoyances with memory reports from /proc/meminfo and free(1). [akpm@linux-foundation.org: standardize comment layout] Reported-by:Russ Anderson <rja@sgi.com> Signed-off-by:
Rafael Aquini <aquini@linux.com> Acked-by:
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KAMEZAWA Hiroyuki authored
During memory hotplug we refresh zonelists when we online a page in a new zone. It means that the node's zonelist is not initialized until pages are onlined. So for example, "nid" passed by MEM_GOING_ONLINE notifier will point to NODE_DATA(nid) which has no zone fallback list. Moreover, if we hot-add cpu-only nodes, alloc_pages() will do no fallback. This patch makes a zonelist when a new pgdata is available. Note: in production, at fujitsu, memory should be onlined before cpu and our server didn't have any memory-less nodes and had no problems. But recent changes in MEM_GOING_ONLINE+page_cgroup will access not initialized zonelist of node. Anyway, there are memory-less node and we need some care. Signed-off-by: -
Borislav Petkov authored
Remove calibrate_delay_direct()'s KERN_DEBUG printk related to bogomips calculation as it appears when booting every core on setups with 'ignore_loglevel' which dmesg people scan for possible issues. As the message doesn't show very useful information to the widest audience of kernel boot message gazers, it should be removed. Introduced by commit d2b46313 ("init/calibrate.c: fix for critical bogoMIPS intermittent calculation failure"). Signed-off-by:
Borislav Petkov <borislav.petkov@amd.com> Cc: Andrew Worsley <amworsley@gmail.com> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:
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Geert Uytterhoeven authored
On m68k (which doesn't support generic hardirqs yet): drivers/w1/masters/ds1wm.c: In function `ds1wm_probe': drivers/w1/masters/ds1wm.c: error: implicit declaration of function `irq_set_irq_type' Signed-off-by:
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Nicolas Kaiser authored
Signed-off-by:
Nicolas Kaiser <nikai@nikai.net> Reviewed-by:
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Pawel Osciak authored
Add maintainers for the videobuf2 V4L2 driver framework. Signed-off-by:
Pawel Osciak <pawel@osciak.com> Acked-by:
Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Signed-off-by:
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Uwe Kleine-König authored
Commit 4440673a ("leds: provide helper to register "leds-gpio" devices") broke the display of the NEW_LEDS menu as it didn't depend on NEW_LEDS and so made "LED drivers" and "LED Triggers" appear at the same level as "LED Support" instead of below it as it was before 4440673a. Moving LEDS_GPIO_REGISTER out of the menuconfig NEW_LEDS fixes this unintended side effect. Reported-by:
Axel Lin <axel.lin@gmail.com> Signed-off-by:
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by:
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Axel Lin authored
We call led_classdev_unregister/led_classdev_register in asic3_led_remove/asic3_led_probe, thus make LEDS_ASIC3 depend on LEDS_CLASS. This patch fixes below build error if LEDS_CLASS is not configured. LD .tmp_vmlinux1 drivers/built-in.o: In function `asic3_led_remove': clkdev.c:(.devexit.text+0x1860): undefined reference to `led_classdev_unregister' drivers/built-in.o: In function `asic3_led_probe': clkdev.c:(.devinit.text+0xcee8): undefined reference to `led_classdev_register' make: *** [.tmp_vmlinux1] Error 1 Signed-off-by: -
Balbir Singh authored
Update my email address. Email will start to the old address bouncing soon Signed-off-by:
Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by:
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Josh Triplett authored
The "hostname" tool falls back to setting the hostname to "localhost" if /etc/hostname does not exist. Distribution init scripts have the same fallback. However, if userspace never calls sethostname, such as when booting with init=/bin/sh, or otherwise booting a minimal system without the usual init scripts, the default hostname of "(none)" remains, unhelpfully appearing in various places such as prompts ("root@(none):~#") and logs. Furthermore, "(none)" doesn't typically resolve to anything useful. Make the default hostname configurable. This removes the need for the standard fallback, provides a useful default for systems that never call sethostname, and makes minimal systems that much more useful with less configuration. Distributions could choose to use "localhost" here to avoid the fallback, while embedded systems may wish to use a specific target hostname. Signed-off-by:David Miller <davem@davemloft.net> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Kel Modderman <kel@otaku42.de> Signed-off-by:
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Dr. David Alan Gilbert authored
BUILD_BUG_ON_ZERO and BUILD_BUG_ON_NULL must return values, even in the CHECKER case otherwise various users of it become syntactically invalid. Signed-off-by:
Dr. David Alan Gilbert <linux@treblig.org> Reviewed-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by:
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Michal Hocko authored
Commit 56de7263 ("mm: compaction: direct compact when a high-order allocation fails") introduced a check for cc->order == -1 in compact_finished. We should continue compacting in that case because the request came from userspace and there is no particular order to compact for. Similar check has been added by 82478fb7 (mm: compaction: prevent division-by-zero during user-requested compaction) for compaction_suitable. The check is, however, done after zone_watermark_ok which uses order as a right hand argument for shifts. Not only watermark check is pointless if we can break out without it but it also uses 1 << -1 which is not well defined (at least from C standard). Let's move the -1 check above zone_watermark_ok. [minchan.kim@gmail.com> - caught compaction_suitable] Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com> Acked-by:
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Steven Rostedt authored
Running a ktest.pl test, I hit the following bug on x86_32: ------------[ cut here ]------------ WARNING: at arch/x86/mm/highmem_32.c:81 __kunmap_atomic+0x64/0xc1() Hardware name: Modules linked in: Pid: 93, comm: sh Not tainted 2.6.39-test+ #1 Call Trace: [<c04450da>] warn_slowpath_common+0x7c/0x91 [<c042f5df>] ? __kunmap_atomic+0x64/0xc1 [<c042f5df>] ? __kunmap_atomic+0x64/0xc1^M [<c0445111>] warn_slowpath_null+0x22/0x24 [<c042f5df>] __kunmap_atomic+0x64/0xc1 [<c04d4a22>] unmap_vmas+0x43a/0x4e0 [<c04d9065>] exit_mmap+0x91/0xd2 [<c0443057>] mmput+0x43/0xad [<c0448358>] exit_mm+0x111/0x119 [<c044855f>] do_exit+0x1ff/0x5fa [<c0454ea2>] ? set_current_blocked+0x3c/0x40 [<c0454f24>] ? sigprocmask+0x7e/0x8e [<c0448b55>] do_group_exit+0x65/0x88 [<c0448b90>] sys_exit_group+0x18/0x1c [<c0c3915f>] sysenter_do_call+0x12/0x38 ---[ end trace 8055f74ea3c0eb62 ]--- Running a ktest.pl git bisect, found the culprit: commit e303297e ("mm: extended batches for generic mmu_gather") But although this was the commit triggering the bug, it was not the one originally responsible for the bug. That was commit d16dfc55 ("mm: mmu_gather rework"). The code in zap_pte_range() has something that looks like the following: pte = pte_offset_map_lock(mm, pmd, addr, &ptl); do { [...] } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap_unlock(pte - 1, ptl); The pte starts off pointing at the first element in the page table directory that was returned by the pte_offset_map_lock(). When it's done with the page, pte will be pointing to anything between the next entry and the first entry of the next page inclusive. By doing a pte - 1, this puts the pte back onto the original page, which is all that pte_unmap_unlock() needs. In most archs (64 bit), this is not an issue as the pte is ignored in the pte_unmap_unlock(). But on 32 bit archs, where things may be kmapped, it is essential that the pte passed to pte_unmap_unlock() resides on the same page that was given by pte_offest_map_lock(). The problem came in d16dfc55 ("mm: mmu_gather rework") where it introduced a "break;" from the while loop. This alone did not seem to easily trigger the bug. But the modifications made by e303297e caused that "break;" to be hit on the first iteration, before the pte++. The pte not being incremented will now cause pte_unmap_unlock(pte - 1) to be pointing to the previous page. This will cause the wrong page to be unmapped, and also trigger the warning above. The simple solution is to just save the pointer given by pte_offset_map_lock() and use it in the unlock. Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by:
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Christian Gmeiner authored
Fix the wrong `if' condition for the check if the requested timer is available. The bitmap avail is used to store if a timer is used already. test_bit() is used to check if the requested timer is available. If a bit in the avail bitmap is set it means that the timer is available. The runtime effect would be that allocating a specific timer always fails (versus telling cs5535_mfgpt_alloc_timer to allocate the first available timer, which works). Signed-off-by:
Christian Gmeiner <christian.gmeiner@gmail.com> Acked-by:
Andres Salomon <dilinger@queued.net> Signed-off-by:
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Axel Lin authored
In the case of goto err_kzalloc, we should kfree target. Signed-off-by:
Pratyush Anand <pratyush.anand@st.com> Signed-off-by:
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KOSAKI Motohiro authored
Recently, Robert Mueller reported (http://lkml.org/lkml/2010/9/12/236) that zone_reclaim_mode doesn't work properly on his new NUMA server (Dual Xeon E5520 + Intel S5520UR MB). He is using Cyrus IMAPd and it's built on a very traditional single-process model. * a master process which reads config files and manages the other process * multiple imapd processes, one per connection * multiple pop3d processes, one per connection * multiple lmtpd processes, one per connection * periodical "cleanup" processes. There are thousands of independent processes. The problem is, recent Intel motherboard turn on zone_reclaim_mode by default and traditional prefork model software don't work well on it. Unfortunatelly, such models are still typical even in the 21st century. We can't ignore them. This patch raises the zone_reclaim_mode threshold to 30. 30 doesn't have any specific meaning. but 20 means that one-hop QPI/Hypertransport and such relatively cheap 2-4 socket machine are often used for traditional servers as above. The intention is that these machines don't use zone_reclaim_mode. Note: ia64 and Power have arch specific RECLAIM_DISTANCE definitions. This patch doesn't change such high-end NUMA machine behavior. Dave Hansen said: : I know specifically of pieces of x86 hardware that set the information : in the BIOS to '21' *specifically* so they'll get the zone_reclaim_mode : behavior which that implies. : : They've done performance testing and run very large and scary benchmarks : to make sure that they _want_ this turned on. What this means for them : is that they'll probably be de-optimized, at least on newer versions of : the kernel. : : If you want to do this for particular systems, maybe _that_'s what we : should do. Have a list of specific configurations that need the : defaults overridden either because they're buggy, or they have an : unusual hardware configuration not really reflected in the distance : table. And later said: : The original change in the hardware tables was for the benefit of a : benchmark. Said benchmark isn't going to get run on mainline until the : next batch of enterprise distros drops, at which point the hardware where : this was done will be irrelevant for the benchmark. I'm sure any new : hardware will just set this distance to another yet arbitrary value to : make the kernel do what it wants. :) : : Also, when the hardware got _set_ to this initially, I complained. So, I : guess I'm getting my way now, with this patch. I'm cool with it. Reported-by:
Robert Mueller <robm@fastmail.fm> Signed-off-by:
Christoph Lameter <cl@linux.com> Acked-by:
David Rientjes <rientjes@google.com> Reviewed-by:
Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by:
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