lwn.git/include/linux, branch v2.6.37.1

xHCI: synchronize irq in xhci_suspend()

2011-02-17T23:15:22+00:00

commit 0029227f1bc30b6c809ae751f9e7af6cef900997 upstream. Synchronize the interrupts instead of free them in xhci_suspend(). This will prevent a double free when the host is suspended and then the card removed. Set the flag hcd->msix_enabled when using MSI-X, and check the flag in suspend_common(). MSI-X synchronization will be handled by xhci_suspend(), and MSI/INTx will be synchronized in suspend_common(). This patch should be queued for the 2.6.37 stable tree. Reported-by: Matthew Garrett Signed-off-by: Andiry Xu Signed-off-by: Sarah Sharp Signed-off-by: Greg Kroah-Hartman

ARM: oprofile: Fix backtraces in timer mode

2011-02-17T23:15:10+00:00

commit d14dd7e20d5e526557f5d3cfef4046a642f80924 upstream. Always allow backtraces when using oprofile on ARM, even if a PMU isn't present. Restores functionality originally introduced in commit 1b7b56982fdcd9d85effd76f3928cf5d6eb26155 ("oprofile: Always allow backtraces on ARM") by Richard Purdie. It is not that obvious, but there is now only one oprofile_arch_init() function. So the .backtrace callback is available also in timer mode. Implemented by removing code and using stubs for oprofile_perf_{init, exit} provided by . This allows cleaning of other architecture specific implementations too. Signed-off-by: Ari Kauppi Acked-by: Will Deacon Signed-off-by: Robert Richter Signed-off-by: Greg Kroah-Hartman

ieee80211: correct IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK macro

2011-02-17T23:15:09+00:00

commit 8d661f1e462d50bd83de87ee628aaf820ce3c66c upstream. It is defined in include/linux/ieee80211.h. As per IEEE spec. bit6 to bit15 in block ack parameter represents buffer size. So the bitmask should be 0xFFC0. Signed-off-by: Amitkumar Karwar Signed-off-by: Bing Zhao Reviewed-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman

oprofile: Fix usage of CONFIG_HW_PERF_EVENTS for oprofile_perf_init and friends

2011-02-17T23:15:08+00:00

commit 1ea1bdf7faa4d0b5293e605f2e1ef1c2c59f6b53 upstream. The implementations are flagged in Makefile with CONFIG_HW_PERF_EVENTS instead of CONFIG_PERF_EVENTS. Signed-off-by: Ari Kauppi Signed-off-by: Robert Richter Signed-off-by: Greg Kroah-Hartman

Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent

2011-02-17T23:15:07+00:00

commit 8c6a98b22b750c9eb52653ba643faa17db8d3881 upstream. Currently sysrq_enabled and __sysrq_enabled are initialised separately and inconsistently, leading to sysrq being actually enabled by reported as not enabled in sysfs. The first change to the sysfs configurable synchronises these two: static int __read_mostly sysrq_enabled = 1; static int __sysrq_enabled; Add a common define to carry the default for these preventing them becoming out of sync again. Default this to 1 to mirror previous behaviour. Signed-off-by: Andy Whitcroft Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman

memory hotplug: one more lock on memory hotplug

2011-02-17T23:14:50+00:00

commit 925268a06dc2b1ff7bfcc37419a6827a0e739639 upstream. Now, memory_hotplug_(un)lock() is used for add/remove/offline pages for avoiding races with hibernation. But this should be held in online_pages(), too. It seems asymmetric. There are cases where one has to avoid a race with memory hotplug notifier and his own local code, and hotplug v.s. hotplug. This will add a generic solution for avoiding races. In other view, having lock here has no big impacts. online pages is tend to be done by udev script at el against each memory section one by one. Then, it's better to have lock here, too. Reviewed-by: Christoph Lameter Acked-by: David Rientjes Signed-off-by: KAMEZAWA Hiroyuki Signed-off-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman

workqueue: relax lockdep annotation on flush_work()

2011-02-17T23:14:43+00:00

commit e159489baa717dbae70f9903770a6a4990865887 upstream. Currently, the lockdep annotation in flush_work() requires exclusive access on the workqueue the target work is queued on and triggers warning if a work is trying to flush another work on the same workqueue; however, this is no longer true as workqueues can now execute multiple works concurrently. This patch adds lock_map_acquire_read() and make process_one_work() hold read access to the workqueue while executing a work and start_flush_work() check for write access if concurrnecy level is one or the workqueue has a rescuer (as only one execution resource - the rescuer - is guaranteed to be available under memory pressure), and read access if higher. This better represents what's going on and removes spurious lockdep warnings which are triggered by fake dependency chain created through flush_work(). * Peter pointed out that flushing another work from a WQ_MEM_RECLAIM wq breaks forward progress guarantee under memory pressure. Condition check accordingly updated. Signed-off-by: Tejun Heo Reported-by: "Rafael J. Wysocki" Tested-by: "Rafael J. Wysocki" Cc: Peter Zijlstra Signed-off-by: Greg Kroah-Hartman

sched: Change wait_for_completion_*_timeout() to return a signed long

2011-02-17T23:14:39+00:00

commit 6bf4123760a5aece6e4829ce90b70b6ffd751d65 upstream. wait_for_completion_*_timeout() can return: 0: if the wait timed out -ve: if the wait was interrupted +ve: if the completion was completed. As they currently return an 'unsigned long', the last two cases are not easily distinguished which can easily result in buggy code, as is the case for the recently added wait_for_completion_interruptible_timeout() call in net/sunrpc/cache.c So change them both to return 'long'. As MAX_SCHEDULE_TIMEOUT is LONG_MAX, a large +ve return value should never overflow. Signed-off-by: NeilBrown Cc: Peter Zijlstra Cc: J. Bruce Fields Cc: Andrew Morton Cc: Linus Torvalds LKML-Reference: <20110105125016.64ccab0e@notabene.brown> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

klist: Fix object alignment on 64-bit.

2011-02-17T23:14:39+00:00

commit 795abaf1e4e188c4171e3cd3dbb11a9fcacaf505 upstream. Commit c0e69a5bbc6f ("klist.c: bit 0 in pointer can't be used as flag") intended to make sure that all klist objects were at least pointer size aligned, but used the constant "4" which only works on 32-bit. Use "sizeof(void *)" which is correct in all cases. Signed-off-by: David S. Miller Acked-by: Jesper Nilsson Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm: page allocator: adjust the per-cpu counter threshold when memory is low

2011-02-17T23:14:38+00:00

commit 88f5acf88ae6a9778f6d25d0d5d7ec2d57764a97 upstream. Commit aa45484 ("calculate a better estimate of NR_FREE_PAGES when memory is low") noted that watermarks were based on the vmstat NR_FREE_PAGES. To avoid synchronization overhead, these counters are maintained on a per-cpu basis and drained both periodically and when a threshold is above a threshold. On large CPU systems, the difference between the estimate and real value of NR_FREE_PAGES can be very high. The system can get into a case where pages are allocated far below the min watermark potentially causing livelock issues. The commit solved the problem by taking a better reading of NR_FREE_PAGES when memory was low. Unfortately, as reported by Shaohua Li this accurate reading can consume a large amount of CPU time on systems with many sockets due to cache line bouncing. This patch takes a different approach. For large machines where counter drift might be unsafe and while kswapd is awake, the per-cpu thresholds for the target pgdat are reduced to limit the level of drift to what should be a safe level. This incurs a performance penalty in heavy memory pressure by a factor that depends on the workload and the machine but the machine should function correctly without accidentally exhausting all memory on a node. There is an additional cost when kswapd wakes and sleeps but the event is not expected to be frequent - in Shaohua's test case, there was one recorded sleep and wake event at least. To ensure that kswapd wakes up, a safe version of zone_watermark_ok() is introduced that takes a more accurate reading of NR_FREE_PAGES when called from wakeup_kswapd, when deciding whether it is really safe to go back to sleep in sleeping_prematurely() and when deciding if a zone is really balanced or not in balance_pgdat(). We are still using an expensive function but limiting how often it is called. When the test case is reproduced, the time spent in the watermark functions is reduced. The following report is on the percentage of time spent cumulatively spent in the functions zone_nr_free_pages(), zone_watermark_ok(), __zone_watermark_ok(), zone_watermark_ok_safe(), zone_page_state_snapshot(), zone_page_state(). vanilla 11.6615% disable-threshold 0.2584% David said: : We had to pull aa454840 "mm: page allocator: calculate a better estimate : of NR_FREE_PAGES when memory is low and kswapd is awake" from 2.6.36 : internally because tests showed that it would cause the machine to stall : as the result of heavy kswapd activity. I merged it back with this fix as : it is pending in the -mm tree and it solves the issue we were seeing, so I : definitely think this should be pushed to -stable (and I would seriously : consider it for 2.6.37 inclusion even at this late date). Signed-off-by: Mel Gorman Reported-by: Shaohua Li Reviewed-by: Christoph Lameter Tested-by: Nicolas Bareil Cc: David Rientjes Cc: Kyle McMartin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman