- 15 Dec, 2016 40 commits
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Matthew Wilcox authored
This probably doubles the size of each item allocated by the test suite but it lets us check a few more things, and may be needed for upcoming API changes that require the caller pass in the order of the entry. Link: http://lkml.kernel.org/r/1480369871-5271-46-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
Matthew Wilcox <mawilcox@microsoft.com> Tested-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Matthew Wilcox authored
item_kill_tree() assumes that everything in the tree is a pointer to a struct item, which is annoying when testing the behaviour of exceptional entries. Fix it to delete exceptional entries on the assumption they don't need to be freed. Link: http://lkml.kernel.org/r/1480369871-5271-45-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
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Matthew Wilcox authored
Calling rcu_barrier() allows all of the rcu-freed memory to be actually returned to the pool, and allows nr_allocated to return to 0. As well as allowing diffs between runs to be more useful, it also lets us pinpoint leaks more effectively. Link: http://lkml.kernel.org/r/1480369871-5271-44-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
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Konstantin Khlebnikov authored
This adds simple benchmark for iterator similar to one I've used for commit 78c1d784 ("radix-tree: introduce bit-optimized iterator") Building with make BENCHMARK=1 set radix tree order to 6, this allows to get performance comparable to in kernel performance. Link: http://lkml.kernel.org/r/1480369871-5271-43-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by:
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Matthew Wilcox authored
Each thread needs to register itself with RCU, otherwise the reading thread's read lock has no effect and the freeing thread will free the memory in the tree without waiting for the read lock to be dropped. Link: http://lkml.kernel.org/r/1480369871-5271-42-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
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Matthew Wilcox authored
Instead of reseeding the random number generator every time around the loop in big_gang_check(), seed it at the beginning of execution. Use rand_r() and an independent base seed for each thread in iteration_test() so they don't stomp all over each others state. Since this particular test depends on the kernel scheduler, the iteration test can't be reproduced based purely on the random seed, but at least it won't pollute the other tests. Print the seed, and allow the seed to be specified so that a run which hits a problem can be reproduced. Link: http://lkml.kernel.org/r/1480369871-5271-41-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
Matthew Wilcox <willy@infradead.org> Tested-by:
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Matthew Wilcox authored
It can be a source of mild concern when the test suite shows that we're leaking nodes. While poring over the source code looking for leaks can lead to some fascinating bugs being discovered, sometimes the leak is simply that these nodes were preallocated and are sitting on the per-CPU list. Free them by calling the CPU dead callback. Link: http://lkml.kernel.org/r/1480369871-5271-40-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
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Matthew Wilcox authored
Rather than simply NOP out preempt_enable() and preempt_disable(), keep track of preempt_count and display it regularly in case either the test suite or the code under test is forgetting to balance the enables & disables. Only found a test-case that was forgetting to re-enable preemption, but it's a possibility worth checking. Link: http://lkml.kernel.org/r/1480369871-5271-39-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
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Matthew Wilcox authored
In order to test the preload code, it is necessary to fail GFP_ATOMIC allocations, which requires defining GFP_KERNEL and GFP_ATOMIC properly. Remove the obsolete __GFP_WAIT and copy the definitions of the __GFP flags which are used from the kernel include files. We also need the real definition of gfpflags_allow_blocking() to persuade the radix tree to actually use its preallocated nodes. Link: http://lkml.kernel.org/r/1480369871-5271-38-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
Matthew Wilcox <willy@linux.intel.com> Tested-by:
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Matthew Wilcox authored
Patch series "Radix tree patches for 4.10", v3. Mostly these are improvements; the only bug fixes in here relate to multiorder entries (which are unused in the 4.9 tree). This patch (of 32): The radix tree uses its own buggy WARN_ON_ONCE. Replace it with the definition from asm-generic/bug.h Link: http://lkml.kernel.org/r/1480369871-5271-37-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
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Jan Kara authored
Currently we never clear dirty tags in DAX mappings and thus address ranges to flush accumulate. Now that we have locking of radix tree entries, we have all the locking necessary to reliably clear the radix tree dirty tag when flushing caches for corresponding address range. Similarly to page_mkclean() we also have to write-protect pages to get a page fault when the page is next written to so that we can mark the entry dirty again. Link: http://lkml.kernel.org/r/1479460644-25076-21-git-send-email-jack@suse.czSigned-off-by:
Jan Kara <jack@suse.cz> Reviewed-by:
Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by:
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Jan Kara authored
Currently PTE gets updated in wp_pfn_shared() after dax_pfn_mkwrite() has released corresponding radix tree entry lock. When we want to writeprotect PTE on cache flush, we need PTE modification to happen under radix tree entry lock to ensure consistent updates of PTE and radix tree (standard faults use page lock to ensure this consistency). So move update of PTE bit into dax_pfn_mkwrite(). Link: http://lkml.kernel.org/r/1479460644-25076-20-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Currently, flushing of caches for DAX mappings was ignoring entry lock. So far this was ok (modulo a bug that a difference in entry lock could cause cache flushing to be mistakenly skipped) but in the following patches we will write-protect PTEs on cache flushing and clear dirty tags. For that we will need more exclusion. So do cache flushing under an entry lock. This allows us to remove one lock-unlock pair of mapping->tree_lock as a bonus. Link: http://lkml.kernel.org/r/1479460644-25076-19-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
DAX will need to implement its own version of page_check_address(). To avoid duplicating page table walking code, export follow_pte() which does what we need. Link: http://lkml.kernel.org/r/1479460644-25076-18-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Currently finish_mkwrite_fault() returns 0 when PTE got changed before we acquired PTE lock and VM_FAULT_WRITE when we succeeded in modifying the PTE. This is somewhat confusing since 0 generally means success, it is also inconsistent with finish_fault() which returns 0 on success. Change finish_mkwrite_fault() to return 0 on success and VM_FAULT_NOPAGE when PTE changed. Practically, there should be no behavioral difference since we bail out from the fault the same way regardless whether we return 0, VM_FAULT_NOPAGE, or VM_FAULT_WRITE. Also note that VM_FAULT_WRITE has no effect for shared mappings since the only two places that check it - KSM and GUP - care about private mappings only. Generally the meaning of VM_FAULT_WRITE for shared mappings is not well defined and we should probably clean that up. Link: http://lkml.kernel.org/r/1479460644-25076-17-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Provide a helper function for finishing write faults due to PTE being read-only. The helper will be used by DAX to avoid the need of complicating generic MM code with DAX locking specifics. Link: http://lkml.kernel.org/r/1479460644-25076-16-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
wp_page_reuse() handles write shared faults which is needed only in wp_page_shared(). Move the handling only into that location to make wp_page_reuse() simpler and avoid a strange situation when we sometimes pass in locked page, sometimes unlocked etc. Link: http://lkml.kernel.org/r/1479460644-25076-15-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
So far we set vmf->page during WP faults only when we needed to pass it to the ->page_mkwrite handler. Set it in all the cases now and use that instead of passing page pointer explicitly around. Link: http://lkml.kernel.org/r/1479460644-25076-14-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
We will need more information in the ->page_mkwrite() helper for DAX to be able to fully finish faults there. Pass vm_fault structure to do_page_mkwrite() and use it there so that information propagates properly from upper layers. Link: http://lkml.kernel.org/r/1479460644-25076-13-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Currently we duplicate handling of shared write faults in wp_page_reuse() and do_shared_fault(). Factor them out into a common function. Link: http://lkml.kernel.org/r/1479460644-25076-12-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Move final handling of COW faults from generic code into DAX fault handler. That way generic code doesn't have to be aware of peculiarities of DAX locking so remove that knowledge and make locking functions private to fs/dax.c. Link: http://lkml.kernel.org/r/1479460644-25076-11-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Introduce finish_fault() as a helper function for finishing page faults. It is rather thin wrapper around alloc_set_pte() but since we'd want to call this from DAX code or filesystems, it is still useful to avoid some boilerplate code. Link: http://lkml.kernel.org/r/1479460644-25076-10-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Patch series "dax: Clear dirty bits after flushing caches", v5. Patchset to clear dirty bits from radix tree of DAX inodes when caches for corresponding pfns have been flushed. In principle, these patches enable handlers to easily update PTEs and do other work necessary to finish the fault without duplicating the functionality present in the generic code. I'd like to thank Kirill and Ross for reviews of the series! This patch (of 20): To allow full handling of COW faults add memcg field to struct vm_fault and a return value of ->fault() handler meaning that COW fault is fully handled and memcg charge must not be canceled. This will allow us to remove knowledge about special DAX locking from the generic fault code. Link: http://lkml.kernel.org/r/1479460644-25076-9-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Add orig_pte field to vm_fault structure to allow ->page_mkwrite handlers to fully handle the fault. This also allows us to save some passing of extra arguments around. Link: http://lkml.kernel.org/r/1479460644-25076-8-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Instead of creating another vm_fault structure, use the one passed to wp_pfn_shared() for passing arguments into pfn_mkwrite handler. Link: http://lkml.kernel.org/r/1479460644-25076-7-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Use vm_fault structure to pass cow_page, page, and entry in and out of the function. That reduces number of __do_fault() arguments from 4 to 1. Link: http://lkml.kernel.org/r/1479460644-25076-6-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Instead of creating another vm_fault structure, use the one passed to __do_fault() for passing arguments into fault handler. Link: http://lkml.kernel.org/r/1479460644-25076-5-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
struct vm_fault has already pgoff entry. Use it instead of passing pgoff as a separate argument and then assigning it later. Link: http://lkml.kernel.org/r/1479460644-25076-4-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Every single user of vmf->virtual_address typed that entry to unsigned long before doing anything with it so the type of virtual_address does not really provide us any additional safety. Just use masked vmf->address which already has the appropriate type. Link: http://lkml.kernel.org/r/1479460644-25076-3-git-send-email-jack@suse.czSigned-off-by:
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Jan Kara authored
Currently we have two different structures for passing fault information around - struct vm_fault and struct fault_env. DAX will need more information in struct vm_fault to handle its faults so the content of that structure would become event closer to fault_env. Furthermore it would need to generate struct fault_env to be able to call some of the generic functions. So at this point I don't think there's much use in keeping these two structures separate. Just embed into struct vm_fault all that is needed to use it for both purposes. Link: http://lkml.kernel.org/r/1479460644-25076-2-git-send-email-jack@suse.czSigned-off-by:
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Lorenzo Stoakes authored
Unexport the low-level __get_user_pages_unlocked() function and replaces invocations with calls to more appropriate higher-level functions. In hva_to_pfn_slow() we are able to replace __get_user_pages_unlocked() with get_user_pages_unlocked() since we can now pass gup_flags. In async_pf_execute() and process_vm_rw_single_vec() we need to pass different tsk, mm arguments so get_user_pages_remote() is the sane replacement in these cases (having added manual acquisition and release of mmap_sem.) Additionally get_user_pages_remote() reintroduces use of the FOLL_TOUCH flag. However, this flag was originally silently dropped by commit 1e987790 ("mm/gup: Introduce get_user_pages_remote()"), so this appears to have been unintentional and reintroducing it is therefore not an issue. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20161027095141.2569-3-lstoakes@gmail.comSigned-off-by:
Lorenzo Stoakes <lstoakes@gmail.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by:
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Lorenzo Stoakes authored
Patch series "mm: unexport __get_user_pages_unlocked()". This patch series continues the cleanup of get_user_pages*() functions taking advantage of the fact we can now pass gup_flags as we please. It firstly adds an additional 'locked' parameter to get_user_pages_remote() to allow for its callers to utilise VM_FAULT_RETRY functionality. This is necessary as the invocation of __get_user_pages_unlocked() in process_vm_rw_single_vec() makes use of this and no other existing higher level function would allow it to do so. Secondly existing callers of __get_user_pages_unlocked() are replaced with the appropriate higher-level replacement - get_user_pages_unlocked() if the current task and memory descriptor are referenced, or get_user_pages_remote() if other task/memory descriptors are referenced (having acquiring mmap_sem.) This patch (of 2): Add a int *locked parameter to get_user_pages_remote() to allow VM_FAULT_RETRY faulting behaviour similar to get_user_pages_[un]locked(). Taking into account the previous adjustments to get_user_pages*() functions allowing for the passing of gup_flags, we are now in a position where __get_user_pages_unlocked() need only be exported for his ability to allow VM_FAULT_RETRY behaviour, this adjustment allows us to subsequently unexport __get_user_pages_unlocked() as well as allowing for future flexibility in the use of get_user_pages_remote(). [sfr@canb.auug.org.au: merge fix for get_user_pages_remote API change] Link: http://lkml.kernel.org/r/20161122210511.024ec341@canb.auug.org.au Link: http://lkml.kernel.org/r/20161027095141.2569-2-lstoakes@gmail.comSigned-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
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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:
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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:
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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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