- 15 Dec, 2016 40 commits
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Davidlohr Bueso authored
We can avoid the idr tree lookup (albeit possibly avoiding idr_find_fast()) when being awoken in EINTR, as the semid will not change in this context while blocked. Use the sma pointer directly and take the sem_lock, then re-check for RMID races. We continue to re-check the queue.status with the lock held such that we can detect situations where we where are dealing with a spurious wakeup but another task that holds the sem_lock updated the queue.status while we were spinning for it. Once we take the lock it obviously won't change again. Being the only caller, get rid of sem_obtain_lock() altogether. Link: http://lkml.kernel.org/r/1478708774-28826-3-git-send-email-dave@stgolabs.netSigned-off-by:
Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Davidlohr Bueso authored
Instead of using the reverse goto, we can simplify the flow and make it more language natural by just doing do-while instead. One would hope this is the standard way (or obviously just with a while bucle) that we do wait/wakeup handling in the kernel. The exact same logic is kept, just more indented. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1478708774-28826-2-git-send-email-dave@stgolabs.netSigned-off-by:
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Davidlohr Bueso authored
... saves some LoC and looks cleaner than re-implementing the calls. Link: http://lkml.kernel.org/r/1474225896-10066-6-git-send-email-dave@stgolabs.netSigned-off-by:
Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
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Davidlohr Bueso authored
The compiler already does this, but make it explicit. This helper is really small and also used in update_queue's main loop, which is O(N^2) scanning. Inline and avoid the function overhead. Link: http://lkml.kernel.org/r/1474225896-10066-5-git-send-email-dave@stgolabs.netSigned-off-by:
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Davidlohr Bueso authored
This is the main workhorse that deals with semop user calls such that the waitforzero or semval update operations, on the set, can complete on not as the sma currently stands. Currently, the set is iterated twice (setting semval, then backwards for the sempid value). Slowpaths, and particularly SEM_UNDO calls, must undo any altered sem when it is detected that the caller must block or has errored-out. With larger sets, there can occur situations where this involves a lot of cycles and can obviously be a suboptimal use of cached resources in shared memory. Ie, discarding CPU caches that are also calling semop and have the sembuf cached (and can complete), while the current lock holder doing the semop will block, error, or does a waitforzero operation. This patch proposes still iterating the set twice, but the first scan is read-only, and we perform the actual updates afterward, once we know that the call will succeed. In order to not suffer from the overhead of dealing with sops that act on the same sem_num, such (rare) cases use perform_atomic_semop_slow(), which is exactly what we have now. Duplicates are detected before grabbing sem_lock, and uses simple a 32/64-bit hash array variable to based on the sem_num we are working on. In addition add some comments to when we expect to the caller to block. [akpm@linux-foundation.org: coding-style fixes] [colin.king@canonical.com: ensure we left shift a ULL rather than a 32 bit integer] Link: http://lkml.kernel.org/r/20161028181129.7311-1-colin.king@canonical.com Link: http://lkml.kernel.org/r/20160921194603.GB21438@linux-80c1.suseSigned-off-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
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Davidlohr Bueso authored
Our sysv sems have been using the notion of lockless wakeups for a while, ever since commit 0a2b9d4c ("ipc/sem.c: move wake_up_process out of the spinlock section"), in order to reduce the sem_lock hold times. This in-house pending queue can be replaced by wake_q (just like all the rest of ipc now), in that it provides the following advantages: o Simplifies and gets rid of unnecessary code. o We get rid of the IN_WAKEUP complexities. Given that wake_q_add() grabs reference to the task, if awoken due to an unrelated event, between the wake_q_add() and wake_up_q() window, we cannot race with sys_exit and the imminent call to wake_up_process(). o By not spinning IN_WAKEUP, we no longer need to disable preemption. In consequence, the wakeup paths (after schedule(), that is) must acknowledge an external signal/event, as well spurious wakeup occurring during the pending wakeup window. Obviously no changes in semantics that could be visible to the user. The fastpath is _only_ for when we know for sure that we were awoken due to a the waker's successful semop call (queue.status is not -EINTR). On a 48-core Haswell, running the ipcscale 'waitforzero' test, the following is seen with increasing thread counts: v4.8-rc5 v4.8-rc5 semopv2 Hmean sembench-sem-2 574733.00 ( 0.00%) 578322.00 ( 0.62%) Hmean sembench-sem-8 811708.00 ( 0.00%) 824689.00 ( 1.59%) Hmean sembench-sem-12 842448.00 ( 0.00%) 845409.00 ( 0.35%) Hmean sembench-sem-21 933003.00 ( 0.00%) 977748.00 ( 4.80%) Hmean sembench-sem-48 935910.00 ( 0.00%) 1004759.00 ( 7.36%) Hmean sembench-sem-79 937186.00 ( 0.00%) 983976.00 ( 4.99%) Hmean sembench-sem-234 974256.00 ( 0.00%) 1060294.00 ( 8.83%) Hmean sembench-sem-265 975468.00 ( 0.00%) 1016243.00 ( 4.18%) Hmean sembench-sem-296 991280.00 ( 0.00%) 1042659.00 ( 5.18%) Hmean sembench-sem-327 975415.00 ( 0.00%) 1029977.00 ( 5.59%) Hmean sembench-sem-358 1014286.00 ( 0.00%) 1049624.00 ( 3.48%) Hmean sembench-sem-389 972939.00 ( 0.00%) 1043127.00 ( 7.21%) Hmean sembench-sem-420 981909.00 ( 0.00%) 1056747.00 ( 7.62%) Hmean sembench-sem-451 990139.00 ( 0.00%) 1051609.00 ( 6.21%) Hmean sembench-sem-482 965735.00 ( 0.00%) 1040313.00 ( 7.72%) [akpm@linux-foundation.org: coding-style fixes] [sfr@canb.auug.org.au: merge fix for WAKE_Q to DEFINE_WAKE_Q rename] Link: http://lkml.kernel.org/r/20161122210410.5eca9fc2@canb.auug.org.au Link: http://lkml.kernel.org/r/1474225896-10066-3-git-send-email-dave@stgolabs.netSigned-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
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Davidlohr Bueso authored
ipc/sem: do not call wake_sem_queue_do() prematurely ... as this call should obviously be paired with its _prepare() counterpart. At least whenever possible, as there is no harm in calling it bogusly as we do now in a few places. Immediate error semop(2) paths that are far from ever having the task block can be simplified and avoid a few unnecessary loads on their way out of the call as it is not deeply nested. Link: http://lkml.kernel.org/r/1474225896-10066-2-git-send-email-dave@stgolabs.netSigned-off-by:
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Babu Moger authored
Implement functions watchdog_nmi_enable and watchdog_nmi_disable to enable/disable nmi watchdog. Sparc uses arch specific nmi watchdog handler. Currently, we do not have a way to enable/disable nmi watchdog dynamically. With these patches we can enable or disable arch specific nmi watchdogs using proc or sysctl interface. Example commands. To enable: echo 1 > /proc/sys/kernel/nmi_watchdog To disable: echo 0 > /proc/sys/kernel/nmi_watchdog It can also achieved using the sysctl parameter kernel.nmi_watchdog Link: http://lkml.kernel.org/r/1478034826-43888-4-git-send-email-babu.moger@oracle.comSigned-off-by:
Babu Moger <babu.moger@oracle.com> Acked-by:
Don Zickus <dzickus@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Josh Hunt <johunt@akamai.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by:
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Babu Moger authored
Separate hardlockup code from watchdog.c and move it to watchdog_hld.c. It is mostly straight forward. Remove everything inside CONFIG_HARDLOCKUP_DETECTORS. This code will go to file watchdog_hld.c. Also update the makefile accordigly. Link: http://lkml.kernel.org/r/1478034826-43888-3-git-send-email-babu.moger@oracle.comSigned-off-by:
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Babu Moger authored
Patch series "Clean up watchdog handlers", v2. This is an attempt to cleanup watchdog handlers. Right now, kernel/watchdog.c implements both softlockup and hardlockup detectors. Softlockup code is generic. Hardlockup code is arch specific. Some architectures don't use hardlockup detectors. They use their own watchdog detectors. To make both these combination work, we have numerous #ifdefs in kernel/watchdog.c. We are trying here to make these handlers independent of each other. Also provide an interface for architectures to implement their own handlers. watchdog_nmi_enable and watchdog_nmi_disable will be defined as weak such that architectures can override its definitions. Thanks to Don Zickus for his suggestions. Here are our previous discussions http://www.spinics.net/lists/sparclinux/msg16543.html http://www.spinics.net/lists/sparclinux/msg16441.html This patch (of 3): Move shared macros and definitions to nmi.h so that watchdog.c, new file watchdog_hld.c or any other architecture specific handler can use those definitions. Link: http://lkml.kernel.org/r/1478034826-43888-2-git-send-email-babu.moger@oracle.comSigned-off-by:
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Pavel Machek authored
Ajdust spelling to more common "mandatory". Variant "mandidory" is certainly wrong. Link: http://lkml.kernel.org/r/20161011073003.GA19476@amdSigned-off-by:
Pavel Machek <pavel@ucw.cz> Acked-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Andrew Morton authored
This cast is no longer needed. Cc: Johannes Berg <johannes.berg@intel.com> Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Cc: Intel Linux Wireless <linuxwifi@intel.com> Cc: Kalle Valo <kvalo@codeaurora.org> Signed-off-by:
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Nicolas Pitre authored
The OpenRISC compiler (so far) fails to optimize away a large portion of code containing a reference to posix_timer_event in alarmtimer.c when CONFIG_POSIX_TIMERS is unset. Let's give it a direct clue to let the build succeed. This fixes [linux-next:master 6682/7183] alarmtimer.c:undefined reference to `posix_timer_event' reported by kbuild test robot. Signed-off-by:
Nicolas Pitre <nico@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Triplett <josh@joshtriplett.org> Signed-off-by:
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Shailesh Pandey authored
This patch fixes below warnings: WARNING: Missing a blank line after declarations WARNING: Block comments use a trailing */ on a separate line ERROR: spaces required around that '=' (ctx:WxV) Above warnings were reported by checkpatch.pl Link: http://lkml.kernel.org/r/1478604980-18062-1-git-send-email-p.shailesh@samsung.comSigned-off-by:
Shailesh Pandey <p.shailesh@samsung.com> Signed-off-by:
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Jiri Slaby authored
When LONG_MIN is passed to msgrcv, one would expect to recieve any message. But convert_mode does *msgtyp = -*msgtyp and -LONG_MIN is undefined. In particular, with my gcc -LONG_MIN produces -LONG_MIN again. So handle this case properly by assigning LONG_MAX to *msgtyp if LONG_MIN was specified as msgtyp to msgrcv. This code: long msg[] = { 100, 200 }; int m = msgget(IPC_PRIVATE, IPC_CREAT | 0644); msgsnd(m, &msg, sizeof(msg), 0); msgrcv(m, &msg, sizeof(msg), LONG_MIN, 0); produces currently nothing: msgget(IPC_PRIVATE, IPC_CREAT|0644) = 65538 msgsnd(65538, {100, "\310\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"}, 16, 0) = 0 msgrcv(65538, ... Except a UBSAN warning: UBSAN: Undefined behaviour in ipc/msg.c:745:13 negation of -9223372036854775808 cannot be represented in type 'long int': With the patch, I see what I expect: msgget(IPC_PRIVATE, IPC_CREAT|0644) = 0 msgsnd(0, {100, "\310\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"}, 16, 0) = 0 msgrcv(0, {100, "\310\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"}, 16, -9223372036854775808, 0) = 16 Link: http://lkml.kernel.org/r/20161024082633.10148-1-jslaby@suse.czSigned-off-by:Jiri Slaby <jslaby@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
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Choosing the appropriate compression option when using an embedded initramfs can result in significant size differences in the resulting data. This is caused by avoiding double compression of the initramfs contents. For example on my tests, choosing CONFIG_INITRAMFS_COMPRESSION_NONE when compressing the kernel using XZ) results in up to 500KiB differences (9MiB to 8.5MiB) in the kernel size as the dictionary will not get polluted with uncomprensible data and may reuse kernel data too. Despite embedding an uncompressed initramfs, a user may want to allow for a compressed extra initramfs to be passed using the rd system, for example to boot a recovery system. 9ba4bcb6 ("initramfs: read CONFIG_RD_ variables for initramfs compression") broke that behavior by making the choice based on CONFIG_RD_* instead of adding CONFIG_INITRAMFS_COMPRESSION_LZ4. Saddly, CONFIG_RD_* is also used to choose the supported RD compression algorithms by the kernel and a user may want to support more than one. This patch also reverts commit 3e4e0f0a ("initramfs: remove "compression mode" choice") restoring back the "compression mode" choice and includes the CONFIG_INITRAMFS_COMPRESSION_LZ4 option which was never added. As a result the following options are added or readed affecting the embedded initramfs compression: INITRAMFS_COMPRESSION_NONE Do no compression INITRAMFS_COMPRESSION_GZIP Compress using gzip INITRAMFS_COMPRESSION_BZIP2 Compress using bzip2 INITRAMFS_COMPRESSION_LZMA Compress using lzma INITRAMFS_COMPRESSION_XZ Compress using xz INITRAMFS_COMPRESSION_LZO Compress using lzo INITRAMFS_COMPRESSION_LZ4 Compress using lz4 These depend on the corresponding CONFIG_RD_* option being set (except NONE which has no dependencies). This patch depends on the previous one (the previous version didn't) to simplify the way in which the algorithm is chosen and keep backwards compatibility with the behaviour introduced by 9ba4bcb6 ("initramfs: read CONFIG_RD_ variables for initramfs compression"). Link: http://lkml.kernel.org/r/57EAD77B.7090607@klondike.esSigned-off-by:
Francisco Blas Izquierdo Riera (klondike) <klondike@klondike.es> Cc: P J P <ppandit@redhat.com> Cc: Paul Bolle <pebolle@tiscali.nl> Signed-off-by:
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Move the current builtin initram compression algorithm selection from the Makefile into the INITRAMFS_COMPRESSION variable. This makes deciding algorithm precedence easier and would allow for overrides if new algorithms want to be tested. Link: http://lkml.kernel.org/r/57EAD769.1090401@klondike.esSigned-off-by:
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Petr Mladek authored
kdb_trap_printk allows to pass normal printk() messages to kdb via vkdb_printk(). For example, it is used to get backtrace using the classic show_stack(), see kdb_show_stack(). vkdb_printf() tries to avoid a potential infinite loop by disabling the trap. But this approach is racy, for example: CPU1 CPU2 vkdb_printf() // assume that kdb_trap_printk == 0 saved_trap_printk = kdb_trap_printk; kdb_trap_printk = 0; kdb_show_stack() kdb_trap_printk++; Problem1: Now, a nested printk() on CPU0 calls vkdb_printf() even when it should have been disabled. It will not cause a deadlock but... // using the outdated saved value: 0 kdb_trap_printk = saved_trap_printk; kdb_trap_printk--; Problem2: Now, kdb_trap_printk == -1 and will stay like this. It means that all messages will get passed to kdb from now on. This patch removes the racy saved_trap_printk handling. Instead, the recursion is prevented by a check for the locked CPU. The solution is still kind of racy. A non-related printk(), from another process, might get trapped by vkdb_printf(). And the wanted printk() might not get trapped because kdb_printf_cpu is assigned. But this problem existed even with the original code. A proper solution would be to get_cpu() before setting kdb_trap_printk and trap messages only from this CPU. I am not sure if it is worth the effort, though. In fact, the race is very theoretical. When kdb is running any of the commands that use kdb_trap_printk there is a single active CPU and the other CPUs should be in a holding pen inside kgdb_cpu_enter(). The only time this is violated is when there is a timeout waiting for the other CPUs to report to the holding pen. Finally, note that the situation is a bit schizophrenic. vkdb_printf() explicitly allows recursion but only from KDB code that calls kdb_printf() directly. On the other hand, the generic printk() recursion is not allowed because it might cause an infinite loop. This is why we could not hide the decision inside vkdb_printf() easily. Link: http://lkml.kernel.org/r/1480412276-16690-4-git-send-email-pmladek@suse.comSigned-off-by:
Petr Mladek <pmladek@suse.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by:
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Petr Mladek authored
kdb_printf_lock does not prevent other CPUs from entering the critical section because it is ignored when KDB_STATE_PRINTF_LOCK is set. The problematic situation might look like: CPU0 CPU1 vkdb_printf() if (!KDB_STATE(PRINTF_LOCK)) KDB_STATE_SET(PRINTF_LOCK); spin_lock_irqsave(&kdb_printf_lock, flags); vkdb_printf() if (!KDB_STATE(PRINTF_LOCK)) BANG: The PRINTF_LOCK state is set and CPU1 is entering the critical section without spinning on the lock. The problem is that the code tries to implement locking using two state variables that are not handled atomically. Well, we need a custom locking because we want to allow reentering the critical section on the very same CPU. Let's use solution from Petr Zijlstra that was proposed for a similar scenario, see https://lkml.kernel.org/r/20161018171513.734367391@infradead.org This patch uses the same trick with cmpxchg(). The only difference is that we want to handle only recursion from the same context and therefore we disable interrupts. In addition, KDB_STATE_PRINTF_LOCK is removed. In fact, we are not able to set it a non-racy way. Link: http://lkml.kernel.org/r/1480412276-16690-3-git-send-email-pmladek@suse.comSigned-off-by:Daniel Thompson <daniel.thompson@linaro.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by:
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Petr Mladek authored
kdb_event state variable is only set but never checked in the kernel code. http://www.spinics.net/lists/kdb/msg01733.html suggests that this variable affected WARN_CONSOLE_UNLOCKED() in the original implementation. But this check never went upstream. The semantic is unclear and racy. The value is updated after the kdb_printf_lock is acquired and after it is released. It should be symmetric at minimum. The value should be manipulated either inside or outside the locked area. Fortunately, it seems that the original function is gone and we could simply remove the state variable. Link: http://lkml.kernel.org/r/1480412276-16690-2-git-send-email-pmladek@suse.comSigned-off-by:
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Douglas Anderson authored
We've got a delay loop waiting for secondary CPUs. That loop uses loops_per_jiffy. However, loops_per_jiffy doesn't actually mean how many tight loops make up a jiffy on all architectures. It is quite common to see things like this in the boot log: Calibrating delay loop (skipped), value calculated using timer frequency.. 48.00 BogoMIPS (lpj=24000) In my case I was seeing lots of cases where other CPUs timed out entering the debugger only to print their stack crawls shortly after the kdb> prompt was written. Elsewhere in kgdb we already use udelay(), so that should be safe enough to use to implement our timeout. We'll delay 1 ms for 1000 times, which should give us a full second of delay (just like the old code wanted) but allow us to notice that we're done every 1 ms. [akpm@linux-foundation.org: simplifications, per Daniel] Link: http://lkml.kernel.org/r/1477091361-2039-1-git-send-email-dianders@chromium.orgSigned-off-by:
Douglas Anderson <dianders@chromium.org> Reviewed-by:
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Kefeng Wang authored
It is fragile that some definitions acquired via transitive dependencies, as shown in below: atomic_* (<linux/atomic.h>) ENOMEM/EN* (<linux/errno.h>) EXPORT_SYMBOL (<linux/export.h>) device_initcall (<linux/init.h>) preempt_* (<linux/preempt.h>) Include them to prevent possible issues. Link: http://lkml.kernel.org/r/1481163221-40170-1-git-send-email-wangkefeng.wang@huawei.comSigned-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Suggested-by:
Mark Rutland <mark.rutland@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by:
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Andreas Platschek authored
Documenation/ubsan.txt was moved to Documentation/dev-tools/ubsan.rst, this fixes the reference. Link: http://lkml.kernel.org/r/1476698152-29340-3-git-send-email-andreas.platschek@opentech.atSigned-off-by:
Andreas Platschek <andreas.platschek@opentech.at> Signed-off-by:
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Andreas Platschek authored
Documentation on development tools was moved to Documentation/devl-tools and sphinxified (renamed from .txt to .rst). References in lib/Kconfig.debug need to be updated to the new location. Link: http://lkml.kernel.org/r/1476698152-29340-2-git-send-email-andreas.platschek@opentech.atSigned-off-by:
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Dan Carpenter authored
Smatch complains that we started using the array offset before we checked that it was valid. Fixes: 017c59c0 ('relay: Use per CPU constructs for the relay channel buffer pointers') Link: http://lkml.kernel.org/r/20161013084947.GC16198@mwandaSigned-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Alexander Duyck authored
Update the driver code so that we do bulk updates of the page reference count instead of just incrementing it by one reference at a time. The advantage to doing this is that we cut down on atomic operations and this in turn should give us a slight improvement in cycles per packet. In addition if we eventually move this over to using build_skb the gains will be more noticeable. Link: http://lkml.kernel.org/r/20161110113616.76501.17072.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
Alexander Duyck <alexander.h.duyck@intel.com> Acked-by:
Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> Cc: Helge Deller <deller@gmx.de> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Keguang Zhang <keguang.zhang@gmail.com> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Steven Miao <realmz6@gmail.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
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Alexander Duyck authored
The ARM architecture provides a mechanism for deferring cache line invalidation in the case of map/unmap. This patch makes use of this mechanism to avoid unnecessary synchronization. A secondary effect of this change is that the portion of the page that has been synchronized for use by the CPU should be writable and could be passed up the stack (at least on ARM). The last bit that occurred to me is that on architectures where the sync_for_cpu call invalidates cache lines we were prefetching and then invalidating the first 128 bytes of the packet. To avoid that I have moved the sync up to before we perform the prefetch and allocate the skbuff so that we can actually make use of it. Link: http://lkml.kernel.org/r/20161110113611.76501.98897.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
Add a function that allows us to batch free a page that has multiple references outstanding. Specifically this function can be used to drop a page being used in the page frag alloc cache. With this drivers can make use of functionality similar to the page frag alloc cache without having to do any workarounds for the fact that there is no function that frees multiple references. Link: http://lkml.kernel.org/r/20161110113606.76501.70752.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
Add support for mapping and unmapping a page with attributes. The primary use for this is currently to allow for us to pass the DMA_ATTR_SKIP_CPU_SYNC attribute when mapping and unmapping a page. On some architectures such as ARM the synchronization has significant overhead and if we are already taking care of the sync_for_cpu and sync_for_device from the driver there isn't much need to handle this in the map/unmap calls as well. Link: http://lkml.kernel.org/r/20161110113601.76501.46095.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113555.76501.52536.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113550.76501.73060.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113544.76501.40008.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113539.76501.6539.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113534.76501.86492.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113529.76501.44762.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113524.76501.87966.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113518.76501.52225.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
Tobias Klauser <tklauser@distanz.ch> Cc: Ley Foon Tan <lftan@altera.com> Signed-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113513.76501.32321.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113508.76501.77583.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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Alexander Duyck authored
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113503.76501.80809.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by:
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