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
...
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
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>
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>
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>
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>
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>
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>
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>
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>
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>
Test this functionality inside the kernel as well as in userspace.
Also remove insert_bug() as there's no comparable thing to test
in the XArray code.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
With no code left in the kernel using the multiorder radix tree, convert
the iteration test from the radix tree to the XArray. It's unlikely to
suffer the same bug as the radix tree, but this test will prevent that
bug from ever creeping into the XArray implementation.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
The tag_tagged_items() function is supposed to test the page-writeback
tagging code. Since that has been converted to the XArray, there's
not much point in testing the radix tree's tagging code. This requires
using the pthread mutex embedded in the xarray instead of an external
lock, so remove the pthread mutexes which protect xarrays/radix trees.
Also remove radix_tree_iter_tag_set() as this was the last user.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
The page cache was the only user of this interface and it has now
been converted to the XArray. Transform the test into a test of
xas_init_marks().
Signed-off-by: Matthew Wilcox <willy@infradead.org>
radix_tree_split and radix_tree_join were never used upstream. Remove
them; if they're needed in future they will be replaced by XArray
equivalents.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
The only user of this functionality was the workingset code, and it's
now been converted to the XArray. Remove __radix_tree_delete_node()
entirely as it was also only used by the workingset code.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
This is a 1:1 conversion. The major part of this patch is converting
the test framework from userspace to kernel space and mirroring the
algorithm now used in find_swap_entry().
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Now the page cache lookup is using the XArray, let's convert this
regression test from the radix tree API to the XArray so it's testing
roughly the same thing it was testing before.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
There's no direct replacement for radix_tree_for_each_contig()
in the XArray API as it's an unusual thing to do. Instead,
open-code a loop using xas_next(). This removes the only user of
radix_tree_for_each_contig() so delete the iterator from the API and
the test suite code for it.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
