Commit Graph

183 Commits

Author SHA1 Message Date
Colin Ian King cac7ea57a0 radix tree test suite: fix incorrect allocation size for pthreads
Currently the pthread allocation for each array item is based on the size
of a pthread_t pointer and should be the size of the pthread_t structure,
so the allocation is under-allocating the correct size.  Fix this by using
the size of each element in the pthreads array.

Static analysis cppcheck reported:
tools/testing/radix-tree/regression1.c:180:2: warning: Size of pointer
'threads' used instead of size of its data. [pointerSize]

Link: https://lkml.kernel.org/r/20230727160930.632674-1-colin.i.king@gmail.com
Fixes: 1366c37ed8 ("radix tree test harness")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:40 -07:00
Liam R. Howlett ef5c3de521 maple_tree: fix node allocation testing on 32 bit
Internal node counting was altered and the 64 bit test was updated,
however the 32bit test was missed.

Restore the 32bit test to a functional state.

Link: https://lore.kernel.org/linux-mm/CAMuHMdV4T53fOw7VPoBgPR7fP6RYqf=CBhD_y_vOg53zZX_DnA@mail.gmail.com/
Link: https://lkml.kernel.org/r/20230712173916.168805-2-Liam.Howlett@oracle.com
Fixes: 541e06b772 ("maple_tree: remove GFP_ZERO from kmem_cache_alloc() and kmem_cache_alloc_bulk()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-17 12:53:22 -07:00
Andrew Morton 63773d2b59 Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
Arnd Bergmann bde1597d0f radix-tree: move declarations to header
The xarray.c file contains the only call to radix_tree_node_rcu_free(),
and it comes with its own extern declaration for it.  This means the
function definition causes a missing-prototype warning:

lib/radix-tree.c:288:6: error: no previous prototype for 'radix_tree_node_rcu_free' [-Werror=missing-prototypes]

Instead, move the declaration for this function to a new header that can
be included by both, and do the same for the radix_tree_node_cachep
variable that has the same underlying problem but does not cause a warning
with gcc.

[zhangpeng.00@bytedance.com: fix building radix tree test suite]
  Link: https://lkml.kernel.org/r/20230521095450.21332-1-zhangpeng.00@bytedance.com
Link: https://lkml.kernel.org/r/20230516194212.548910-1-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-12 11:31:50 -07:00
Liam R. Howlett eaf9790d3b maple_tree: add __init and __exit to test module
The test functions are not needed after the module is removed, so mark
them as such.  Add __exit to the module removal function.  Some other
variables have been marked as const static as well.

Link: https://lkml.kernel.org/r/20230518145544.1722059-20-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vernon Yang <vernon2gm@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:31 -07:00
Liam R. Howlett a5199577b1 maple_tree: make test code work without debug enabled
The test code is less useful without debug, but can still do general
validations.  Define mt_dump(), mas_dump() and mas_wr_dump() as a noop if
debug is not enabled and document it in the test module information that
more information can be obtained with another kernel config option.

MT_BUG_ON() will report a failures without tree dumps, and the output will
be less useful.

Link: https://lkml.kernel.org/r/20230518145544.1722059-17-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vernon Yang <vernon2gm@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:31 -07:00
Liam R. Howlett 89f499f35c maple_tree: add format option to mt_dump()
Allow different formatting strings to be used when dumping the tree. 
Currently supports hex and decimal.

Link: https://lkml.kernel.org/r/20230518145544.1722059-6-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vernon Yang <vernon2gm@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:28 -07:00
Liam R. Howlett 633769c926 maple_tree: avoid unnecessary ascending
The maple tree node limits are implied by the parent.  When walking up the
tree, the limit may not be known until a slot that does not have implied
limits are encountered.  However, if the node is the left-most or
right-most node, the walking up to find that limit can be skipped.

This commit also fixes the debug/testing code that was not setting the
limit on walking down the tree as that optimization is not compatible with
this change.

Link: https://lkml.kernel.org/r/20230518145544.1722059-4-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vernon Yang <vernon2gm@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:27 -07:00
Peng Zhang 3b7939c8e5 maple_tree: add a test case to check maple_alloc
Add a test case to check whether the number of maple_alloc structures is
actually equal to mas->alloc->total.

Link: https://lkml.kernel.org/r/20230411041005.26205-2-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:56 -07:00
Liam R. Howlett c13af03de4 maple_tree: fix write memory barrier of nodes once dead for RCU mode
During the development of the maple tree, the strategy of freeing multiple
nodes changed and, in the process, the pivots were reused to store
pointers to dead nodes.  To ensure the readers see accurate pivots, the
writers need to mark the nodes as dead and call smp_wmb() to ensure any
readers can identify the node as dead before using the pivot values.

There were two places where the old method of marking the node as dead
without smp_wmb() were being used, which resulted in RCU readers seeing
the wrong pivot value before seeing the node was dead.  Fix this race
condition by using mte_set_node_dead() which has the smp_wmb() call to
ensure the race is closed.

Add a WARN_ON() to the ma_free_rcu() call to ensure all nodes being freed
are marked as dead to ensure there are no other call paths besides the two
updated paths.

This is necessary for the RCU mode of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-6-surenb@google.com
Fixes: 54a611b605 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 18:06:21 -07:00
Vernon Yang c5d5546ea0 maple_tree: remove the parameter entry of mas_preallocate
The parameter entry of mas_preallocate is not used, so drop it.

Link: https://lkml.kernel.org/r/20230110154211.1758562-1-vernon2gm@gmail.com
Signed-off-by: Vernon Yang <vernon2gm@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:52 -08:00
Liam Howlett 541e06b772 maple_tree: remove GFP_ZERO from kmem_cache_alloc() and kmem_cache_alloc_bulk()
Preallocations are common in the VMA code to avoid allocating under
certain locking conditions.  The preallocations must also cover the
worst-case scenario.  Removing the GFP_ZERO flag from the
kmem_cache_alloc() (and bulk variant) calls will reduce the amount of time
spent zeroing memory that may not be used.  Only zero out the necessary
area to keep track of the allocations in the maple state.  Zero the entire
node prior to using it in the tree.

This required internal changes to node counting on allocation, so the test
code is also updated.

This restores some micro-benchmark performance: up to +9% in mmtests mmap1
by my testing +10% to +20% in mmap, mmapaddr, mmapmany tests reported by
Red Hat

Link: https://bugzilla.redhat.com/show_bug.cgi?id=2149636
Link: https://lkml.kernel.org/r/20230105160427.2988454-1-Liam.Howlett@oracle.com
Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com>
Reported-by: Jirka Hladky <jhladky@redhat.com>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:54 -08:00
Liam Howlett 9102b78b6f maple_tree: update copyright dates for test code
Add the span to the year of the development.

Link: https://lkml.kernel.org/r/20221025173709.2718725-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-15 16:37:49 -08:00
Liam Howlett 120b116208 maple_tree: reorganize testing to restore module testing
Along the development cycle, the testing code support for module/in-kernel
compiles was removed.  Restore this functionality by moving any internal
API tests to the userspace side, as well as threading tests.  Fix the
lockdep issues and add a way to reduce memory usage so the tests can
complete with KASAN + memleak detection.  Make the tests work on 32 bit
hosts where possible and detect 32 bit hosts in the radix test suite.

[akpm@linux-foundation.org: fix module export]
[akpm@linux-foundation.org: fix it some more]
[liam.howlett@oracle.com: fix compile warnings on 32bit build in check_find()]
  Link: https://lkml.kernel.org/r/20221107203816.1260327-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20221028180415.3074673-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:22 -08:00
Liam R. Howlett e15e06a839 lib/test_maple_tree: add testing for maple tree
This is a test suite that uses the radix test infrastructure.  It has been
split into its own commit to allow for easier review of the maple tree
code.

The testing includes:
- Allocation of nodes
- gfp flag allocation checks
- Expansion & contraction of tree
- preallocation checks
- tree navigation by next/prev
- tree navigation by iterators (mas_for_each, etc)
- Number of nodes for a given number of entries
- Generic tree construction tests
- Addition and removal of entries in forward and reverse numerical indexes
- gap searching both forward and reverse
- Combining gaps by overwriting entries in different ways
- splitting right-most node
- splitting left-most node
- overwriting multiple slots
- overwriting across different levels of the tree
- overwriting the middle of a tree
- causing a 3-way split up to the root by overwriting the last slot and
  first slot of different nodes and spanning different levels
- RCU stress testing of the tree with threads
- Duplication of the tree by entry count
- Tests which were generated by fuzzers have been added.
- A large number of tests which come from recording crashing in a VM and
  reconstructing the tree (see check_erase2_set())

Link: https://lkml.kernel.org/r/20220906194824.2110408-8-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:14 -07:00
Liam R. Howlett c349fa1818 radix tree test suite: add lockdep_is_held to header
maple tree uses lockdep_is_held, so define it as external in the header.

Link: https://lkml.kernel.org/r/20220906194824.2110408-7-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:14 -07:00
Liam R. Howlett cc86e0c2f3 radix tree test suite: add support for slab bulk APIs
Add support for kmem_cache_free_bulk() and kmem_cache_alloc_bulk() to the
radix tree test suite.

Link: https://lkml.kernel.org/r/20220906194824.2110408-6-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:14 -07:00
Liam R. Howlett 000a449345 radix tree test suite: add allocation counts and size to kmem_cache
Add functions to get the number of allocations, and total allocations from
a kmem_cache.  Also add a function to get the allocated size and a way to
zero the total allocations.

Link: https://lkml.kernel.org/r/20220906194824.2110408-5-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:14 -07:00
Liam R. Howlett e73cb368be radix tree test suite: add kmem_cache_set_non_kernel()
kmem_cache_set_non_kernel() is a mechanism to allow a certain number of
kmem_cache_alloc requests to succeed even when GFP_KERNEL is not set in
the flags.  This functionality allows for testing different paths though
the code.

Link: https://lkml.kernel.org/r/20220906194824.2110408-4-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:13 -07:00
Liam R. Howlett fbeea9d117 radix tree test suite: add pr_err define
define pr_err to printk

Link: https://lkml.kernel.org/r/20220906194824.2110408-3-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:13 -07:00
Liam R. Howlett 54a611b605 Maple Tree: add new data structure
Patch series "Introducing the Maple Tree"

The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently.  There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface.  If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.

The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes.  With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses.  The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.

The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct.  The
long term goal is to reduce or remove the mmap_lock contention.

The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers.  A single write operation will be
allowed at a time.  A reader re-walks if stale data is encountered.  VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.

Davidlor said

: Yes I like the maple tree, and at this stage I don't think we can ask for
: more from this series wrt the MM - albeit there seems to still be some
: folks reporting breakage.  Fundamentally I see Liam's work to (re)move
: complexity out of the MM (not to say that the actual maple tree is not
: complex) by consolidating the three complimentary data structures very
: much worth it considering performance does not take a hit.  This was very
: much a turn off with the range locking approach, which worst case scenario
: incurred in prohibitive overhead.  Also as Liam and Matthew have
: mentioned, RCU opens up a lot of nice performance opportunities, and in
: addition academia[1] has shown outstanding scalability of address spaces
: with the foundation of replacing the locked rbtree with RCU aware trees.

A similar work has been discovered in the academic press

	https://pdos.csail.mit.edu/papers/rcuvm:asplos12.pdf

Sheer coincidence.  We designed our tree with the intention of solving the
hardest problem first.  Upon settling on a b-tree variant and a rough
outline, we researched ranged based b-trees and RCU b-trees and did find
that article.  So it was nice to find reassurances that we were on the
right path, but our design choice of using ranges made that paper unusable
for us.

This patch (of 70):

The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently.  There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface.  If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.

The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes.  With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses.  The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.

The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct.  The
long term goal is to reduce or remove the mmap_lock contention.

The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers.  A single write operation will be
allowed at a time.  A reader re-walks if stale data is encountered.  VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.

There is additional BUG_ON() calls added within the tree, most of which
are in debug code.  These will be replaced with a WARN_ON() call in the
future.  There is also additional BUG_ON() calls within the code which
will also be reduced in number at a later date.  These exist to catch
things such as out-of-range accesses which would crash anyways.

Link: https://lkml.kernel.org/r/20220906194824.2110408-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220906194824.2110408-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:13 -07:00
Matthew Wilcox (Oracle) b9663a6ff8 tools: Add kmem_cache_alloc_lru()
Turn kmem_cache_alloc() into a wrapper around kmem_cache_alloc_lru().

Fixes: 9bbdc0f324 ("xarray: use kmem_cache_alloc_lru to allocate xa_node")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Li Wang <liwang@redhat.com>
2022-04-22 14:24:28 -04:00
Karolina Drobnik aa0eab8639 tools: Move gfp.h and slab.h from radix-tree to lib
Merge radix-tree definitions from gfp.h and slab.h with these
in tools/lib, so they can be used in other test suites.
Fix style issues in slab.h. Update radix-tree test files.

Signed-off-by: Karolina Drobnik <karolinadrobnik@gmail.com>
Signed-off-by: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/r/b76ddb8a12fdf9870b55c1401213e44f5e0d0da3.1643796665.git.karolinadrobnik@gmail.com
2022-02-20 08:44:37 +02:00
Matthew Wilcox (Oracle) d6e6a27d96 tools: Fix math.h breakage
Commit 98e1385ef2 ("include/linux/radix-tree.h: replace kernel.h with
the necessary inclusions") broke the radix tree test suite in two
different ways; first by including math.h which didn't exist in the
tools directory, and second by removing an implicit include of
spinlock.h before lockdep.h.  Fix both issues.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-30 09:14:42 -08:00
Matthew Wilcox (Oracle) 2c7e57a027 idr test suite: Improve reporting from idr_find_test_1
Instead of just reporting an assertion failure, report enough information
that we can start diagnosing exactly went wrong.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-04-01 07:50:42 -04:00
Matthew Wilcox (Oracle) 094ffbd1d8 idr test suite: Create anchor before launching throbber
The throbber could race with creation of the anchor entry and cause the
IDR to have zero entries in it, which would cause the test to fail.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-04-01 07:50:19 -04:00
Matthew Wilcox (Oracle) 703586410d idr test suite: Take RCU read lock in idr_find_test_1
When run on a single CPU, this test would frequently access already-freed
memory.  Due to timing, this bug never showed up on multi-CPU tests.

Reported-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-04-01 07:44:48 -04:00
Matthew Wilcox (Oracle) 1bb4bd266c radix tree test suite: Register the main thread with the RCU library
Several test runners register individual worker threads with the
RCU library, but neglect to register the main thread, which can lead
to objects being freed while the main thread is in what appears to be
an RCU critical section.

Reported-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-04-01 07:41:30 -04:00
Matthew Wilcox (Oracle) 7487de534d radix tree test suite: Fix compilation
Commit 4bba4c4bb0 added tools/include/linux/compiler_types.h which
includes linux/compiler-gcc.h.  Unfortunately, we had our own (empty)
compiler_types.h which overrode the one added by that commit, and
so we lost the definition of __must_be_array().  Removing our empty
compiler_types.h fixes the problem and reduces our divergence from the
rest of the tools.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-03-30 13:44:35 -04:00
Matthew Wilcox (Oracle) a219b856a2 ida: Free allocated bitmap in error path
If a bitmap needs to be allocated, and then by the time the thread
is scheduled to be run again all the indices which would satisfy the
allocation have been allocated then we would leak the allocation.  Almost
impossible to hit in practice, but a trivial fix.  Found by Coverity.

Fixes: f32f004cdd ("ida: Convert to XArray")
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-07 09:11:33 -04:00
Matthew Wilcox (Oracle) dd841a749d radix tree test suite: Fix compilation
Introducing local_lock broke compilation; fix it all up.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-07 09:07:49 -04:00
Linus Torvalds ff2ae607c6 SPDX patches for 5.7-rc1.
Here are 3 SPDX patches for 5.7-rc1.
 
 One fixes up the SPDX tag for a single driver, while the other two go
 through the tree and add SPDX tags for all of the .gitignore files as
 needed.
 
 Nothing too complex, but you will get a merge conflict with your current
 tree, that should be trivial to handle (one file modified by two things,
 one file deleted.)
 
 All 3 of these have been in linux-next for a while, with no reported
 issues other than the merge conflict.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

Pull SPDX updates from Greg KH:
 "Here are three SPDX patches for 5.7-rc1.

  One fixes up the SPDX tag for a single driver, while the other two go
  through the tree and add SPDX tags for all of the .gitignore files as
  needed.

  Nothing too complex, but you will get a merge conflict with your
  current tree, that should be trivial to handle (one file modified by
  two things, one file deleted.)

  All three of these have been in linux-next for a while, with no
  reported issues other than the merge conflict"

* tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
  ASoC: MT6660: make spdxcheck.py happy
  .gitignore: add SPDX License Identifier
  .gitignore: remove too obvious comments
2020-04-03 13:12:26 -07:00
Masahiro Yamada d198b34f38 .gitignore: add SPDX License Identifier
Add SPDX License Identifier to all .gitignore files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 11:50:48 +01:00
Matthew Wilcox (Oracle) 7e934cf5ac xarray: Fix early termination of xas_for_each_marked
xas_for_each_marked() is using entry == NULL as a termination condition
of the iteration. When xas_for_each_marked() is used protected only by
RCU, this can however race with xas_store(xas, NULL) in the following
way:

TASK1                                   TASK2
page_cache_delete()         	        find_get_pages_range_tag()
                                          xas_for_each_marked()
                                            xas_find_marked()
                                              off = xas_find_chunk()

  xas_store(&xas, NULL)
    xas_init_marks(&xas);
    ...
    rcu_assign_pointer(*slot, NULL);
                                              entry = xa_entry(off);

And thus xas_for_each_marked() terminates prematurely possibly leading
to missed entries in the iteration (translating to missing writeback of
some pages or a similar problem).

If we find a NULL entry that has been marked, skip it (unless we're trying
to allocate an entry).

Reported-by: Jan Kara <jack@suse.cz>
CC: stable@vger.kernel.org
Fixes: ef8e5717db ("page cache: Convert delete_batch to XArray")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-03-12 17:42:08 -04:00
Matthew Wilcox (Oracle) 34eee836a9 radix tree test suite: Support kmem_cache alignment
The radix tree doesn't use alignment, so the argument was ignored.
The maple tree needs its nodes to be aligned, so we need to pay attention
to the alignment argument.  Also change the types of 'size' and 'align'
to unsigned int to match commit f4957d5bd0.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-02-27 12:25:47 -05:00
Linus Torvalds 46f1ec23a4 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The changes in this cycle are:

   - RCU flavor consolidation cleanups and optmizations

   - Documentation updates

   - Miscellaneous fixes

   - SRCU updates

   - RCU-sync flavor consolidation

   - Torture-test updates

   - Linux-kernel memory-consistency-model updates, most notably the
     addition of plain C-language accesses"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits)
  tools/memory-model: Improve data-race detection
  tools/memory-model: Change definition of rcu-fence
  tools/memory-model: Expand definition of barrier
  tools/memory-model: Do not use "herd" to refer to "herd7"
  tools/memory-model: Fix comment in MP+poonceonces.litmus
  Documentation: atomic_t.txt: Explain ordering provided by smp_mb__{before,after}_atomic()
  rcu: Don't return a value from rcu_assign_pointer()
  rcu: Force inlining of rcu_read_lock()
  rcu: Fix irritating whitespace error in rcu_assign_pointer()
  rcu: Upgrade sync_exp_work_done() to smp_mb()
  rcutorture: Upper case solves the case of the vanishing NULL pointer
  torture: Suppress propagating trace_printk() warning
  rcutorture: Dump trace buffer for callback pipe drain failures
  torture: Add --trust-make to suppress "make clean"
  torture: Make --cpus override idleness calculations
  torture: Run kernel build in source directory
  torture: Add function graph-tracing cheat sheet
  torture: Capture qemu output
  rcutorture: Tweak kvm options
  rcutorture: Add trivial RCU implementation
  ...
2019-07-08 15:45:14 -07:00
Linus Torvalds 01305db842 XArray updates for 5.2-rc6
Account XArray nodes for the page cache to the appropriate cgroup
   (Johannes Weiner)
 Fix idr_get_next() when called under the RCU lock (Matthew Wilcox)
 Add a test for xa_insert() (Matthew Wilcox)
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Merge tag 'xarray-5.2-rc6' of git://git.infradead.org/users/willy/linux-dax

Pull XArray fixes from Matthew Wilcox:

 - Account XArray nodes for the page cache to the appropriate cgroup
   (Johannes Weiner)

 - Fix idr_get_next() when called under the RCU lock (Matthew Wilcox)

 - Add a test for xa_insert() (Matthew Wilcox)

* tag 'xarray-5.2-rc6' of git://git.infradead.org/users/willy/linux-dax:
  XArray tests: Add check_insert
  idr: Fix idr_get_next race with idr_remove
  mm: fix page cache convergence regression
2019-06-29 17:14:57 +08:00
Ingo Molnar 83086d654d Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull rcu/next + tools/memory-model changes from Paul E. McKenney:

 - RCU flavor consolidation cleanups and optmizations
 - Documentation updates
 - Miscellaneous fixes
 - SRCU updates
 - RCU-sync flavor consolidation
 - Torture-test updates
 - Linux-kernel memory-consistency-model updates, most notably the addition of plain C-language accesses

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-28 19:46:47 +02:00
Andrea Parri 9129b017b5 rcu: Don't return a value from rcu_assign_pointer()
Quoting Paul [1]:

  "Given that a quick (and perhaps error-prone) search of the uses
   of rcu_assign_pointer() in v5.1 didn't find a single use of the
   return value, let's please instead change the documentation and
   implementation to eliminate the return value."

[1] https://lkml.kernel.org/r/20190523135013.GL28207@linux.ibm.com

Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-06-13 15:38:34 -07:00
Thomas Gleixner 2025cf9e19 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 263 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Matthew Wilcox (Oracle) 5c089fd0c7 idr: Fix idr_get_next race with idr_remove
If the entry is deleted from the IDR between the call to
radix_tree_iter_find() and rcu_dereference_raw(), idr_get_next()
will return NULL, which will end the iteration prematurely.  We should
instead continue to the next entry in the IDR.  This only happens if the
iteration is protected by the RCU lock.  Most IDR users use a spinlock
or semaphore to exclude simultaneous modifications.  It was noticed once
the PID allocator was converted to use the IDR, as it uses the RCU lock,
but there may be other users elsewhere in the kernel.

We can't use the normal pattern of calling radix_tree_deref_retry()
(which catches both a retry entry in a leaf node and a node entry in
the root) as the IDR supports storing entries which are unaligned,
which will trigger an infinite loop if they are encountered.  Instead,
we have to explicitly check whether the entry is a retry entry.

Fixes: 0a835c4f09 ("Reimplement IDR and IDA using the radix tree")
Reported-by: Brendan Gregg <bgregg@netflix.com>
Tested-by: Brendan Gregg <bgregg@netflix.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2019-06-02 23:00:24 -04:00
Matthew Wilcox eff3860bbf radix tree: Don't return retry entries from lookup
Commit 66ee620f06 ("idr: Permit any valid kernel pointer to be stored")
changed the radix tree lookup so that it stops when reaching the bottom
of the tree.  However, the condition was added in the wrong place,
making it possible to return retry entries to the caller.  Reorder the
tests to check for the retry entry before checking whether we're at the
bottom of the tree.  The retry entry should never be found in the tree
root, so it's safe to defer the check until the end of the loop.

Add a regression test to the test-suite to be sure this doesn't come
back.

Fixes: 66ee620f06 ("idr: Permit any valid kernel pointer to be stored")
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-12-06 08:26:16 -05:00
Matthew Wilcox 3a08cd52c3 radix tree: Remove multiorder support
All users have now been converted to the XArray.  Removing the support
reduces code size and ensures new users will use the XArray instead.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:48 -04:00
Matthew Wilcox 542980aa93 radix tree test: Convert multiorder tests to XArray
This is the last remaining user of the multiorder functionality of the
radix tree.  Test the XArray instead.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:48 -04:00
Matthew Wilcox b66b5a48b8 radix tree tests: Convert item_delete_rcu to XArray
In preparation for the removal of the multiorder radix tree code,
convert item_delete_rcu() to use the XArray so it can still be called
for XArrays containing multi-index entries.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:48 -04:00
Matthew Wilcox ccc89e30fa radix tree tests: Convert item_kill_tree to XArray
In preparation for the removal of the multiorder radix tree code,
convert item_kill_tree() to use the XArray so it can still be called
for XArrays containing multi-index entries.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:47 -04:00
Matthew Wilcox 4bb53bdda0 radix tree tests: Move item_insert_order
The remaining tests are not suitable for moving in-kernel, so move
item_insert_order() into multiorder.c, make it static and make it use
the XArray.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:47 -04:00
Matthew Wilcox 879a9ae7b5 radix tree test suite: Remove multiorder benchmarking
The multiorder radix tree code is being removed, so remove the
benchmarking of its performance.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:47 -04:00
Matthew Wilcox 9076b33d7d radix tree test suite: Remove __item_insert
Inline it into its one caller

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:47 -04:00
Matthew Wilcox 4f06d6302d xarray: Move multiorder_check to in-kernel tests
This version is a little less thorough in order to be a little quicker,
but tests the important edge cases.  Also test adding a multiorder entry
at a non-canonical index, and erasing it.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:46 -04:00