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Allocations and frees are globally serialized on the pcpu lock (and the
CPU hotplug lock if enabled, which is the case on Debian).
At least one frequent consumer allocates 4 back-to-back counters (and
frees them in the same manner), exacerbating the problem.
While this does not fully remedy scalability issues, it is a step
towards that goal and provides immediate relief.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Link: https://lore.kernel.org/r/20230823050609.2228718-2-mjguzik@gmail.com
[Dennis: reflowed a few lines]
Signed-off-by: Dennis Zhou <dennis@kernel.org>
On powerpc64le checksum kunit tests work:
[ 2.011457][ T1] KTAP version 1
[ 2.011662][ T1] # Subtest: checksum
[ 2.011848][ T1] 1..3
[ 2.034710][ T1] ok 1 test_csum_fixed_random_inputs
[ 2.079325][ T1] ok 2 test_csum_all_carry_inputs
[ 2.127102][ T1] ok 3 test_csum_no_carry_inputs
[ 2.127202][ T1] # checksum: pass:3 fail:0 skip:0 total:3
[ 2.127533][ T1] # Totals: pass:3 fail:0 skip:0 total:3
[ 2.127956][ T1] ok 1 checksum
But on powerpc64 and powerpc32 they fail:
[ 1.859890][ T1] KTAP version 1
[ 1.860041][ T1] # Subtest: checksum
[ 1.860201][ T1] 1..3
[ 1.861927][ T58] # test_csum_fixed_random_inputs: ASSERTION FAILED at lib/checksum_kunit.c:243
[ 1.861927][ T58] Expected result == expec, but
[ 1.861927][ T58] result == 54991 (0xd6cf)
[ 1.861927][ T58] expec == 33316 (0x8224)
[ 1.863742][ T1] not ok 1 test_csum_fixed_random_inputs
[ 1.864520][ T60] # test_csum_all_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:267
[ 1.864520][ T60] Expected result == expec, but
[ 1.864520][ T60] result == 255 (0xff)
[ 1.864520][ T60] expec == 65280 (0xff00)
[ 1.868820][ T1] not ok 2 test_csum_all_carry_inputs
[ 1.869977][ T62] # test_csum_no_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:306
[ 1.869977][ T62] Expected result == expec, but
[ 1.869977][ T62] result == 64515 (0xfc03)
[ 1.869977][ T62] expec == 0 (0x0)
[ 1.872060][ T1] not ok 3 test_csum_no_carry_inputs
[ 1.872102][ T1] # checksum: pass:0 fail:3 skip:0 total:3
[ 1.872458][ T1] # Totals: pass:0 fail:3 skip:0 total:3
[ 1.872791][ T1] not ok 3 checksum
This is because all expected values were calculated for X86 which
is little endian. On big endian systems all precalculated 16 bits
halves must be byte swapped.
And this is confirmed by a huge amount of sparse errors when building
with C=2
So fix all sparse errors and it will naturally work on all endianness.
Fixes: 688eb8191b47 ("x86/csum: Improve performance of `csum_partial`")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid setting the variables until necessary, and actually use the
variables where applicable. Introducing a variable for the slots array
avoids spanning multiple lines.
Add the missing argument to the documentation.
Use the node type when setting the metadata instead of blindly assuming
the type.
Finally, add a trace point to the function for successful store.
Link: https://lkml.kernel.org/r/20230819004356.1454718-3-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "New page table range API", v6.
This patchset changes the API used by the MM to set up page table entries.
The four APIs are:
set_ptes(mm, addr, ptep, pte, nr)
update_mmu_cache_range(vma, addr, ptep, nr)
flush_dcache_folio(folio)
flush_icache_pages(vma, page, nr)
flush_dcache_folio() isn't technically new, but no architecture
implemented it, so I've done that for them. The old APIs remain around
but are mostly implemented by calling the new interfaces.
The new APIs are based around setting up N page table entries at once.
The N entries belong to the same PMD, the same folio and the same VMA, so
ptep++ is a legitimate operation, and locking is taken care of for you.
Some architectures can do a better job of it than just a loop, but I have
hesitated to make too deep a change to architectures I don't understand
well.
One thing I have changed in every architecture is that PG_arch_1 is now a
per-folio bit instead of a per-page bit when used for dcache clean/dirty
tracking. This was something that would have to happen eventually, and it
makes sense to do it now rather than iterate over every page involved in a
cache flush and figure out if it needs to happen.
The point of all this is better performance, and Fengwei Yin has measured
improvement on x86. I suspect you'll see improvement on your architecture
too. Try the new will-it-scale test mentioned here:
https://lore.kernel.org/linux-mm/20230206140639.538867-5-fengwei.yin@intel.com/
You'll need to run it on an XFS filesystem and have
CONFIG_TRANSPARENT_HUGEPAGE set.
This patchset is the basis for much of the anonymous large folio work
being done by Ryan, so it's received quite a lot of testing over the last
few months.
This patch (of 38):
Determine if a value lies within a range more efficiently (subtraction +
comparison vs two comparisons and an AND). It also has useful (under some
circumstances) behaviour if the range exceeds the maximum value of the
type. Convert all the conflicting definitions of in_range() within the
kernel; some can use the generic definition while others need their own
definition.
Link: https://lkml.kernel.org/r/20230802151406.3735276-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230802151406.3735276-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The current implementation of append may cause duplicate data and/or
incorrect ranges to be returned to a reader during an update. Although
this has not been reported or seen, disable the append write operation
while the tree is in rcu mode out of an abundance of caution.
During the analysis of the mas_next_slot() the following was
artificially created by separating the writer and reader code:
Writer: reader:
mas_wr_append
set end pivot
updates end metata
Detects write to last slot
last slot write is to start of slot
store current contents in slot
overwrite old end pivot
mas_next_slot():
read end metadata
read old end pivot
return with incorrect range
store new value
Alternatively:
Writer: reader:
mas_wr_append
set end pivot
updates end metata
Detects write to last slot
last lost write to end of slot
store value
mas_next_slot():
read end metadata
read old end pivot
read new end pivot
return with incorrect range
set old end pivot
There may be other accesses that are not safe since we are now updating
both metadata and pointers, so disabling append if there could be rcu
readers is the safest action.
Link: https://lkml.kernel.org/r/20230819004356.1454718-2-Liam.Howlett@oracle.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sparse is not happy to see non-static variable without declaration:
lib/vsprintf.c:61:6: warning: symbol 'no_hash_pointers' was not declared.
Should it be static?
Declare respective variable in the sprintf.h. With this, add a comment to
discourage its use if no real need.
Link: https://lkml.kernel.org/r/20230814163344.17429-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "lib/vsprintf: Rework header inclusions", v3.
Some patches that reduce the mess with the header inclusions related to
vsprintf.c module. Each patch has its own description, and has no
dependencies to each other, except the collisions over modifications of
the same places. Hence the series.
This patch (of 2):
kernel.h is being used as a dump for all kinds of stuff for a long time.
sprintf() and friends are used in many drivers without need of the full
kernel.h dependency train with it.
Here is the attempt on cleaning it up by splitting out sprintf() and
friends.
Link: https://lkml.kernel.org/r/20230814163344.17429-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20230814163344.17429-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reorder the operations for split and spanning stores so that new data is
placed in the tree prior to marking the old data as dead. This will limit
re-walks on dead data to just once instead of a retry loop.
The order of operations is as follows: Create the new data, put the new
data in place, mark the top node of the old data as dead.
Then repair parent links in the reused nodes through all levels of the
tree, following the new nodes downwards. Finally walk the top dead node
looking for nodes that are no longer used, or subtrees that should be
destroyed (marked dead throughout then freed), follow the partially used
nodes downwards to discover other dead nodes and subtrees.
Link: https://lkml.kernel.org/r/20230804165951.2661157-7-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
All calls to mas_adopt_children() currently pass the parent as the node in
the maple state. Allow for the parent pointer that is passed in to be
used instead.
Link: https://lkml.kernel.org/r/20230804165951.2661157-6-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a definition to shorten long code lines and clarify what the code is
doing. Use the new definition to get the maple tree parent pointer from
the maple state where possible.
Link: https://lkml.kernel.org/r/20230804165951.2661157-5-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mas_replace() has a single user that takes a flag which is now always
true. Replace this function with mas_put_in_tree() to better align with
mas_replace_node(). Inline the remaining logic into the only caller;
mas_wmb_replace().
Link: https://lkml.kernel.org/r/20230804165951.2661157-4-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replacing nodes may cause a live lock-up if CPU resources are saturated by
write operations on the tree by continuously retrying on dead nodes. To
avoid the continuous retry scenario, ensure the new node is inserted into
the tree prior to marking the old data as dead. This will define a window
where old and new data is swapped.
When reusing lower level nodes, ensure the parent pointer is updated after
the parent is marked dead. This ensures that the child is still reachable
from the top of the tree, but walking up to a dead node will result in a
single retry that will start a fresh walk from the top down through the
new node.
Link: https://lkml.kernel.org/r/20230804165951.2661157-3-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "maple_tree: Change replacement strategy".
The maple tree marks nodes dead as soon as they are going to be replaced.
This could be problematic when used in the RCU context since the writer
may be starved of CPU time by the readers. This patch set addresses the
issue by switching the data replacement strategy to one that will only
mark data as dead once the new data is available.
This series changes the ordering of the node replacement so that the new
data is live before the old data is marked 'dead'. When readers hit
'dead' nodes, they will restart from the top of the tree and end up in the
new data.
In more complex scenarios, the replacement strategy means a subtree is
built and graphed into the tree leaving some nodes to point to the old
parent. The view of tasks into the old data will either remain with the
old data, or see the new data once the old data is marked 'dead'.
Iterators will see the 'dead' node and restart on their own and switch to
the new data. There is no risk of the reader seeing old data in these
cases.
The 'dead' subtree of data is then fully marked dead, but reused nodes
will still point to the dead nodes until the parent pointer is updated.
Walking up to a 'dead' node will cause a re-walk from the top of the tree
and enter the new data area where old data is not reachable.
Once the parent pointers are fully up to date in the active data, the
'dead' subtree is iterated to collect entirely 'dead' subtrees, and dead
nodes (nodes that partially contained reused data).
This patch (of 6):
When dumping the tree, honour formatting request to output hex for the
maple node type arange64.
Link: https://lkml.kernel.org/r/20230804165951.2661157-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20230804165951.2661157-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Recent versions of clang warn about an unused variable, though older
versions saw the 'slot++' as a use and did not warn:
radix-tree.c:1136:50: error: parameter 'slot' set but not used [-Werror,-Wunused-but-set-parameter]
It's clearly not needed any more, so just remove it.
Link: https://lkml.kernel.org/r/20230811131023.2226509-1-arnd@kernel.org
Fixes: 3a08cd52c37c7 ("radix tree: Remove multiorder support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Rong Tao <rongtao@cestc.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add parameter descriptions to struct kunit_attr header for the
parameters attr_default and print.
Fixes: 39e92cb1e4a1 ("kunit: Add test attributes API structure")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308180127.VD7YRPGa-lkp@intel.com/
Signed-off-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
When adding koject or kset, we have made sure that ktype cannot be NULL.
Therefore, after adding koject or kset, there is no need to worry about
ktype being NULL. Clear all ktype-related redundancy checks.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20230805084114.1298-3-thunder.leizhen@huaweicloud.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When I register a kset in the following way:
static struct kset my_kset;
kobject_set_name(&my_kset.kobj, "my_kset");
ret = kset_register(&my_kset);
A null pointer dereference exception is occurred:
[ 4453.568337] Unable to handle kernel NULL pointer dereference at \
virtual address 0000000000000028
... ...
[ 4453.810361] Call trace:
[ 4453.813062] kobject_get_ownership+0xc/0x34
[ 4453.817493] kobject_add_internal+0x98/0x274
[ 4453.822005] kset_register+0x5c/0xb4
[ 4453.825820] my_kobj_init+0x44/0x1000 [my_kset]
... ...
Because I didn't initialize my_kset.kobj.ktype.
According to the description in Documentation/core-api/kobject.rst:
- A ktype is the type of object that embeds a kobject. Every structure
that embeds a kobject needs a corresponding ktype.
So add sanity check to make sure kset->kobj.ktype is not NULL.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20230805084114.1298-2-thunder.leizhen@huaweicloud.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cross-merge networking fixes after downstream PR.
Conflicts:
drivers/net/ethernet/sfc/tc.c
fa165e194997 ("sfc: don't unregister flow_indr if it was never registered")
3bf969e88ada ("sfc: add MAE table machinery for conntrack table")
https://lore.kernel.org/all/20230818112159.7430e9b4@canb.auug.org.au/
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The APIs that allow backtracing across CPUs have always had a way to
exclude the current CPU. This convenience means callers didn't need to
find a place to allocate a CPU mask just to handle the common case.
Let's extend the API to take a CPU ID to exclude instead of just a
boolean. This isn't any more complex for the API to handle and allows the
hardlockup detector to exclude a different CPU (the one it already did a
trace for) without needing to find space for a CPU mask.
Arguably, this new API also encourages safer behavior. Specifically if
the caller wants to avoid tracing the current CPU (maybe because they
already traced the current CPU) this makes it more obvious to the caller
that they need to make sure that the current CPU ID can't change.
[akpm@linux-foundation.org: fix trigger_allbutcpu_cpu_backtrace() stub]
Link: https://lkml.kernel.org/r/20230804065935.v4.1.Ia35521b91fc781368945161d7b28538f9996c182@changeid
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace internal logic with separate bitrev library.
Link: https://lkml.kernel.org/r/20230730081717.1498217-1-sanpeqf@gmail.com
Signed-off-by: John Sanpe <sanpeqf@gmail.com>
Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It is expected that most callers should _ignore_ the errors return by
debugfs_create_dir() in ei_debugfs_init().
Link: https://lkml.kernel.org/r/20230719144355.6720-1-machel@vivo.com
Signed-off-by: Wang Ming <machel@vivo.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It is expected that most callers should _ignore_ the errors return by
debugfs_create_dir() in err_inject_init().
Link: https://lkml.kernel.org/r/20230713082455.2415-1-machel@vivo.com
Signed-off-by: Wang Ming <machel@vivo.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kmap() has been deprecated in favor of the kmap_local_page() due to high
cost, restricted mapping space, the overhead of a global lock for
synchronization, and making the process sleep in the absence of free
slots.
kmap_local_page() is faster than kmap() and offers thread-local and
CPU-local mappings, take pagefaults in a local kmap region and preserves
preemption by saving the mappings of outgoing tasks and restoring those of
the incoming one during a context switch.
The mappings are kept thread local in the functions “dmirror_do_read”
and “dmirror_do_write” in test_hmm.c
Therefore, replace kmap() with kmap_local_page() and use
mempcy_from/to_page() to avoid open coding kmap_local_page() + memcpy() +
kunmap_local().
Remove the unused variable “tmp”.
Link: https://lkml.kernel.org/r/20230610175712.GA348514@sumitra.com
Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Deepak R Varma <drv@mailo.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mas_prealloc() may walk partially down the tree before finding that a
split or spanning store is needed. When the write occurs, relax the
logic on resetting the walk so that partial walks will not restart, but
walks that have gone too far (a store that affects beyond the current
node) should be restarted.
Link: https://lkml.kernel.org/r/20230724183157.3939892-15-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Calculate the number of nodes based on the pending write action instead
of assuming the worst case.
This addresses a performance regression introduced in platforms that
have longer allocation timing.
Link: https://lkml.kernel.org/r/20230724183157.3939892-14-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Relocate it and call mas_wr_extend_null() from within mas_wr_end_piv().
Extending the NULL may affect the end pivot value so call
mas_wr_endtend_null() from within mas_wr_end_piv() to keep it all
together.
Link: https://lkml.kernel.org/r/20230724183157.3939892-12-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mas_rebalance() is called to rebalance an insufficient node into a
single node or two sufficient nodes. The preallocation estimate is
always too many in this case as the height of the tree will never grow
and there is no possibility to have a three way split in this case, so
revise the node allocation count.
Link: https://lkml.kernel.org/r/20230724183157.3939892-9-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The current preallocation strategy is to preallocate the absolute
worst-case allocation for a tree modification. The entry (or NULL) is
needed to know how many nodes are needed to write to the tree. Start by
adding the argument to the mas_preallocate() definition.
Link: https://lkml.kernel.org/r/20230724183157.3939892-8-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add some benchmarking functions in testing for mas_prev(). This is
useful to ensure there are no regressions added during modifications.
Link: https://lkml.kernel.org/r/20230724183157.3939892-3-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Reduce preallocations for maple tree", v3.
Initial work on preallocations showed no regression in performance during
testing, but recently some users (both on [1] and off [android] list) have
reported that preallocating the worst-case number of nodes has caused some
slow down. This patch set addresses the number of allocations in a few
ways.
During munmap() most munmap() operations will remove a single VMA, so
leverage the fact that the maple tree can place a single pointer at range
0 - 0 without allocating. This is done by changing the index of the VMAs
to be indexed by the count, starting at 0.
Re-introduce the entry argument to mas_preallocate() so that a more
intelligent guess of the node count can be made.
Implement the more intelligent guess of the node count, although there is
more work to be done.
During development of v2 of this patch set, I also noticed that the number
of nodes being allocated for a rebalance was beyond what could possibly be
needed. This is addressed in patch 0008.
This patch (of 15):
Add a way to test the speed of mas_for_each() to the testing code.
Link: https://lkml.kernel.org/r/20230724183157.3939892-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20230724183157.3939892-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use lockdep to check the write path in the maple tree holds the lock in
write mode.
Introduce mt_write_lock_is_held() to check if the lock is held for
writing. Update the necessary checks for rcu_dereference_protected() to
use the new write lock check.
Link: https://lkml.kernel.org/r/20230714195551.894800-5-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oliver Sang <oliver.sang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace FGP_FLAGS with GFP_FLAGS
Link: https://lkml.kernel.org/r/20230715084038.987955-1-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace "Insert and entry at a give index" with "Insert an entry at a
given index"
Link: https://lkml.kernel.org/r/20230715143920.994812-1-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
test_pages() tests the page allocator by calling alloc_pages() with
different orders up to order 10.
However, different architectures and platforms support different maximum
contiguous allocation sizes. The default maximum allocation order
(MAX_ORDER) is 10, but architectures can use CONFIG_ARCH_FORCE_MAX_ORDER
to override this. On platforms where this is less than 10, test_meminit()
will blow up with a WARN(). This is expected, so let's not do that.
Replace the hardcoded "10" with the MAX_ORDER macro so that we test
allocations up to the expected platform limit.
Link: https://lkml.kernel.org/r/20230714015238.47931-1-ajd@linux.ibm.com
Fixes: 5015a300a522 ("lib: introduce test_meminit module")
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Xiaoke Wang <xkernel.wang@foxmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The internal function mas_first_entry() is no longer used, so drop it.
Link: https://lkml.kernel.org/r/20230711035444.526-9-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace mas_logical_pivot() with mas_safe_pivot() and drop
mas_logical_pivot() since it won't be used anymore. We can do this since
now all nodes will have node limit pivot (if it is not full node).
Link: https://lkml.kernel.org/r/20230711035444.526-8-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Instead of using mas_first_entry() to find the leftmost leaf, use a simple
loop instead. Remove an unneeded check for root node. To make the error
message more accurate, check pivots first and then slots, because checking
slots depend on the node limit pivot to break the loop.
Link: https://lkml.kernel.org/r/20230711035444.526-7-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Update mas_validate_limits() to check root node, check node limit pivot if
there is enough room for it to exist and check data_end. Remove the check
for child existence as it is done in mas_validate_child_slot().
Link: https://lkml.kernel.org/r/20230711035444.526-6-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Don't break the loop before checking the last slot. Also here check if
non-leaf nodes are missing children.
Link: https://lkml.kernel.org/r/20230711035444.526-5-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Make mas_validate_gaps() check whether the offset in the metadata points
to the largest gap. By the way, simplify this function.
Add the verification that gaps beyond the node limit are zero.
Link: https://lkml.kernel.org/r/20230711035444.526-4-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Improve the validation for maple tree and some cleanup", v2.
This patch (of 7):
Do not use a special offset to indicate that there is no gap. When there
is no gap, offset can point to any valid slots because its gap is 0.
Link: https://lkml.kernel.org/r/20230711035444.526-1-zhangpeng.00@bytedance.com
Link: https://lkml.kernel.org/r/20230711035444.526-3-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When expanding a range in two directions, only partially overwriting the
previous and next ranges, the number of entries will not be increased, so
we can just update the pivots as a fast path. However, it may introduce
potential risks in RCU mode, because it updates two pivots. We only
enable it in non-RCU mode.
Link: https://lkml.kernel.org/r/20230628073657.75314-5-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When the new range can be completely covered by the original last range
without touching the boundaries on both sides, two new entries can be
appended to the end as a fast path. We update the original last pivot at
the end, and the newly appended two entries will not be accessed before
this, so it is also safe in RCU mode.
This is useful for sequential insertion, which is what we do in
dup_mmap(). Enabling BENCH_FORK in test_maple_tree and just running
bench_forking() gives the following time-consuming numbers:
before: after:
17,874.83 msec 15,738.38 msec
It shows about a 12% performance improvement for duplicating VMAs.
Link: https://lkml.kernel.org/r/20230628073657.75314-4-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Optimize the fast path of mas_store()", v4.
Add fast paths for mas_wr_append() and mas_wr_slot_store() respectively.
The newly added fast path of mas_wr_append() is used in fork() and how
much it benefits fork() depends on how many VMAs are duplicated.
Thanks Liam for the review.
This patch (of 4):
Add tests for all cases of mas_wr_append() and mas_wr_slot_store().
Link: https://lkml.kernel.org/r/20230628073657.75314-1-zhangpeng.00@bytedance.com
Link: https://lkml.kernel.org/r/20230628073657.75314-2-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The documentation of mt_next() claims that it starts the search at the
provided index. That's incorrect as it starts the search after the
provided index.
The documentation of mt_find() is slightly confusing. "Handles locking"
is not really helpful as it does not explain how the "locking" works.
Also the documentation of index talks about a range, while in reality the
index is updated on a succesful search to the index of the found entry
plus one.
Fix similar issues for mt_find_after() and mt_prev().
Reword the confusing "Note: Will not return the zero entry." comment on
mt_for_each() and document @__index correctly.
Link: https://lkml.kernel.org/r/87ttw2n556.ffs@tglx
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Shanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
