A bug was found in the find_closest() (find_closest_descending() is also
affected after some testing), where for certain values with small
progressions of 1, 2 & 3, the rounding (done by averaging 2 values) causes
an incorrect index to be returned.
The bug is described in more detail in the commit which fixes the bug.
This commit adds a kunit test to validate that the fix works correctly.
This kunit test adds some of the arrays (from the driver-sphere) that seem
to produce issues with the 'find_closest()' macro. Specifically the one
from ad7606 driver (with which the bug was found) and from the ina2xx
drivers, which shows the quirk with 'find_closest()' with elements in a
array that have an interval of 3.
For the find_closest_descending() tests, the same arrays are used as for
the find_closest(), but in reverse; the idea is that
'find_closest_descending()' should return the sames indices as
'find_closest()' but in reverse.
For testing both macros, there are 4 special arrays created, one for
testing find_closest{_descending}() for arrays of progressions 1, 2, 3 and
4. The idea is to show that (for progressions of 1, 2 & 3) the fix works
as expected. When removing the fix, the issues should start to show up.
Then an extra array of negative and positive values is added. There are
currently no such arrays within drivers, but one could expect that these
macros behave correctly even for such arrays.
To run this kunit:
./tools/testing/kunit/kunit.py run "*util_macros*"
Link: https://lkml.kernel.org/r/20241105145406.554365-2-aardelean@baylibre.com
Signed-off-by: Alexandru Ardelean <aardelean@baylibre.com>
Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A bug was found in the find_closest() (find_closest_descending() is also
affected after some testing), where for certain values with small
progressions, the rounding (done by averaging 2 values) causes an
incorrect index to be returned. The rounding issues occur for
progressions of 1, 2 and 3. It goes away when the progression/interval
between two values is 4 or larger.
It's particularly bad for progressions of 1. For example if there's an
array of 'a = { 1, 2, 3 }', using 'find_closest(2, a ...)' would return 0
(the index of '1'), rather than returning 1 (the index of '2'). This
means that for exact values (with a progression of 1), find_closest() will
misbehave and return the index of the value smaller than the one we're
searching for.
For progressions of 2 and 3, the exact values are obtained correctly; but
values aren't approximated correctly (as one would expect). Starting with
progressions of 4, all seems to be good (one gets what one would expect).
While one could argue that 'find_closest()' should not be used for arrays
with progressions of 1 (i.e. '{1, 2, 3, ...}', the macro should still
behave correctly.
The bug was found while testing the 'drivers/iio/adc/ad7606.c',
specifically the oversampling feature.
For reference, the oversampling values are listed as:
static const unsigned int ad7606_oversampling_avail[7] = {
1, 2, 4, 8, 16, 32, 64,
};
When doing:
1. $ echo 1 > /sys/bus/iio/devices/iio\:device0/oversampling_ratio
$ cat /sys/bus/iio/devices/iio\:device0/oversampling_ratio
1 # this is fine
2. $ echo 2 > /sys/bus/iio/devices/iio\:device0/oversampling_ratio
$ cat /sys/bus/iio/devices/iio\:device0/oversampling_ratio
1 # this is wrong; 2 should be returned here
3. $ echo 3 > /sys/bus/iio/devices/iio\:device0/oversampling_ratio
$ cat /sys/bus/iio/devices/iio\:device0/oversampling_ratio
2 # this is fine
4. $ echo 4 > /sys/bus/iio/devices/iio\:device0/oversampling_ratio
$ cat /sys/bus/iio/devices/iio\:device0/oversampling_ratio
4 # this is fine
And from here-on, the values are as correct (one gets what one would
expect.)
While writing a kunit test for this bug, a peculiar issue was found for the
array in the 'drivers/hwmon/ina2xx.c' & 'drivers/iio/adc/ina2xx-adc.c'
drivers. While running the kunit test (for 'ina226_avg_tab' from these
drivers):
* idx = find_closest([-1 to 2], ina226_avg_tab, ARRAY_SIZE(ina226_avg_tab));
This returns idx == 0, so value.
* idx = find_closest(3, ina226_avg_tab, ARRAY_SIZE(ina226_avg_tab));
This returns idx == 0, value 1; and now one could argue whether 3 is
closer to 4 or to 1. This quirk only appears for value '3' in this
array, but it seems to be a another rounding issue.
* And from 4 onwards the 'find_closest'() works fine (one gets what one
would expect).
This change reworks the find_closest() macros to also check the difference
between the left and right elements when 'x'. If the distance to the right
is smaller (than the distance to the left), the index is incremented by 1.
This also makes redundant the need for using the DIV_ROUND_CLOSEST() macro.
In order to accommodate for any mix of negative + positive values, the
internal variables '__fc_x', '__fc_mid_x', '__fc_left' & '__fc_right' are
forced to 'long' type. This also addresses any potential bugs/issues with
'x' being of an unsigned type. In those situations any comparison between
signed & unsigned would be promoted to a comparison between 2 unsigned
numbers; this is especially annoying when '__fc_left' & '__fc_right'
underflow.
The find_closest_descending() macro was also reworked and duplicated from
the find_closest(), and it is being iterated in reverse. The main reason
for this is to get the same indices as 'find_closest()' (but in reverse).
The comparison for '__fc_right < __fc_left' favors going the array in
ascending order.
For example for array '{ 1024, 512, 256, 128, 64, 16, 4, 1 }' and x = 3, we
get:
__fc_mid_x = 2
__fc_left = -1
__fc_right = -2
Then '__fc_right < __fc_left' evaluates to true and '__fc_i++' becomes 7
which is not quite incorrect, but 3 is closer to 4 than to 1.
This change has been validated with the kunit from the next patch.
Link: https://lkml.kernel.org/r/20241105145406.554365-1-aardelean@baylibre.com
Fixes: 95d119528b0b ("util_macros.h: add find_closest() macro")
Signed-off-by: Alexandru Ardelean <aardelean@baylibre.com>
Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Remove the use of contractions and use proper punctuation in #error
directive messages that discourage the direct inclusion of header files.
Link: https://lkml.kernel.org/r/20241105032231.28833-1-natanielfarzan@gmail.com
Signed-off-by: Nataniel Farzan <natanielfarzan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Syzbot has reported the following KMSAN splat:
BUG: KMSAN: uninit-value in ocfs2_file_read_iter+0x9a4/0xf80
ocfs2_file_read_iter+0x9a4/0xf80
__io_read+0x8d4/0x20f0
io_read+0x3e/0xf0
io_issue_sqe+0x42b/0x22c0
io_wq_submit_work+0xaf9/0xdc0
io_worker_handle_work+0xd13/0x2110
io_wq_worker+0x447/0x1410
ret_from_fork+0x6f/0x90
ret_from_fork_asm+0x1a/0x30
Uninit was created at:
__alloc_pages_noprof+0x9a7/0xe00
alloc_pages_mpol_noprof+0x299/0x990
alloc_pages_noprof+0x1bf/0x1e0
allocate_slab+0x33a/0x1250
___slab_alloc+0x12ef/0x35e0
kmem_cache_alloc_bulk_noprof+0x486/0x1330
__io_alloc_req_refill+0x84/0x560
io_submit_sqes+0x172f/0x2f30
__se_sys_io_uring_enter+0x406/0x41c0
__x64_sys_io_uring_enter+0x11f/0x1a0
x64_sys_call+0x2b54/0x3ba0
do_syscall_64+0xcd/0x1e0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Since an instance of 'struct kiocb' may be passed from the block layer
with 'private' field uninitialized, introduce 'ocfs2_iocb_init_rw_locked()'
and use it from where 'ocfs2_dio_end_io()' might take care, i.e. in
'ocfs2_file_read_iter()' and 'ocfs2_file_write_iter()'.
Link: https://lkml.kernel.org/r/20241029091736.1501946-1-dmantipov@yandex.ru
Fixes: 7cdfc3a1c397 ("ocfs2: Remember rw lock level during direct io")
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Reported-by: syzbot+a73e253cca4f0230a5a5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a73e253cca4f0230a5a5
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit introduces documentation for hung_task_detect_count in
kernel.rst.
Link: https://lkml.kernel.org/r/20241027120747.42833-3-ioworker0@gmail.com
Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Cc: Bang Li <libang.li@antgroup.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Huang Cun <cunhuang@tencent.com>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: John Siddle <jsiddle@redhat.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Yongliang Gao <leonylgao@tencent.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "add detect count for hung tasks", v2.
This patchset adds a counter, hung_task_detect_count, to track the number
of times hung tasks are detected.
IHMO, hung tasks are a critical metric. Currently, we detect them by
periodically parsing dmesg. However, this method isn't as user-friendly
as using a counter.
Sometimes, a short-lived issue with NIC or hard drive can quickly decrease
the hung_task_warnings to zero. Without warnings, we must directly access
the node to ensure that there are no more hung tasks and that the system
has recovered. After all, load average alone cannot provide a clear
picture.
Once this counter is in place, in a high-density deployment pattern, we
plan to set hung_task_timeout_secs to a lower number to improve stability,
even though this might result in false positives. And then we can set a
time-based threshold: if hung tasks last beyond this duration, we will
automatically migrate containers to other nodes. Based on past
experience, this approach could help avoid many production disruptions.
Moreover, just like other important events such as OOM that already have
counters, having a dedicated counter for hung tasks makes sense ;)
This patch (of 2):
This commit adds a counter, hung_task_detect_count, to track the number of
times hung tasks are detected.
IHMO, hung tasks are a critical metric. Currently, we detect them by
periodically parsing dmesg. However, this method isn't as user-friendly as
using a counter.
Sometimes, a short-lived issue with NIC or hard drive can quickly decrease
the hung_task_warnings to zero. Without warnings, we must directly access
the node to ensure that there are no more hung tasks and that the system
has recovered. After all, load average alone cannot provide a clear
picture.
Once this counter is in place, in a high-density deployment pattern, we
plan to set hung_task_timeout_secs to a lower number to improve stability,
even though this might result in false positives. And then we can set a
time-based threshold: if hung tasks last beyond this duration, we will
automatically migrate containers to other nodes. Based on past experience,
this approach could help avoid many production disruptions.
Moreover, just like other important events such as OOM that already have
counters, having a dedicated counter for hung tasks makes sense.
[ioworker0@gmail.com: proc_doulongvec_minmax instead of proc_dointvec]
Link: https://lkml.kernel.org/r/20241101114833.8377-1-ioworker0@gmail.com
Link: https://lkml.kernel.org/r/20241027120747.42833-1-ioworker0@gmail.com
Link: https://lkml.kernel.org/r/20241027120747.42833-2-ioworker0@gmail.com
Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com>
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Cc: Bang Li <libang.li@antgroup.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Huang Cun <cunhuang@tencent.com>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: John Siddle <jsiddle@redhat.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Yongliang Gao <leonylgao@tencent.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref) to
use optimized implementation and ease register pressure around the
primitive for targets that implement optimized variant.
Link: https://lkml.kernel.org/r/20241007083921.47525-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Coccinelle complains about the nested reuse of the pointer `iter' with
different pointer type:
./fs/proc/kcore.c:515:26-30: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:534:23-27: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:550:40-44: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:568:27-31: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:581:28-32: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:599:27-31: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:607:38-42: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:614:26-30: ERROR: invalid reference to the index variable of the iterator on line 499
Replacing `struct kcore_list *iter' with `struct kcore_list *tmp' doesn't change the
scope and the functionality is the same and coccinelle seems happy.
NOTE: There was an issue with using `struct kcore_list *pos' as the nested iterator.
The build did not work!
[akpm@linux-foundation.org: s/tmp/pos/]
Link: https://lkml.kernel.org/r/20241029054651.86356-2-mtodorovac69@gmail.com
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Link: https://lkml.kernel.org/r/20220331223700.902556-1-jakobkoschel@gmail.com
Fixes: 04d168c6d42d ("fs/proc/kcore.c: remove check of list iterator against head past the loop body")
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Brian Johannesmeyer" <bjohannesmeyer@gmail.com>
Cc: Cristiano Giuffrida <c.giuffrida@vu.nl>
Cc: "Bos, H.J." <h.j.bos@vu.nl>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Yan Zhen <yanzhen@vivo.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, if __region_intersects() finds any overlapped but unmatched
resource, it walks the descendant resource tree to check for overlapped
and matched descendant resources using for_each_resource(). However, in
current kernel, for_each_resource() iterates not only the descendant tree,
but also subsequent sibling trees in certain scenarios. While this
doesn't introduce bugs, it makes code hard to be understood and
potentially inefficient.
So, the patch revises next_resource() and for_each_resource() and makes
for_each_resource() traverse the subtree under the specified subtree root
only. Test shows that this avoids unnecessary resource tree walking in
__region_intersects().
For the example resource tree as follows,
X
|
A----D----E
|
B--C
if 'A' is the overlapped but unmatched resource, original kernel
iterates 'B', 'C', 'D', 'E' when it walks the descendant tree. While
the patched kernel iterates only 'B', 'C'.
Thanks David Hildenbrand for providing a good resource tree example.
Link: https://lkml.kernel.org/r/20241029122735.79164-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dlm_errmsg() has been unused since 2010's commit 0016eedc4185
("ocfs2_dlmfs: Use the stackglue.")
Remove dlm_errmsg() and the message table it indexes.
Link: https://lkml.kernel.org/r/20241022002543.302606-1-linux@treblig.org
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fix a typo: panicing -> panicking.
Via codespell.
Link: https://lkml.kernel.org/r/20241027133540.22090-1-algonell@gmail.com
Signed-off-by: Andrew Kreimer <algonell@gmail.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Do not require the presence of `$balanced_parens` to get the commit SHA;
this allows a `Fixes: deadbeef` tag to get a correct suggestion rather
than a suggestion containing a reference to HEAD.
Given this patch:
: From: Tamir Duberstein <tamird@gmail.com>
: Subject: Test patch
: Date: Fri, 25 Oct 2024 19:30:51 -0400
:
: This is a test patch.
:
: Fixes: bd17e036b495
: Signed-off-by: Tamir Duberstein <tamird@gmail.com>
: --- /dev/null
: +++ b/new-file
: @@ -0,0 +1 @@
: +Test.
Before:
WARNING: Please use correct Fixes: style 'Fixes: <12 chars of sha1> ("<title line>")' - ie: 'Fixes: c10a7d25e68f ("Test patch")'
After:
WARNING: Please use correct Fixes: style 'Fixes: <12 chars of sha1> ("<title line>")' - ie: 'Fixes: bd17e036b495 ("checkpatch: warn for non-standard fixes tag style")'
The prior behavior incorrectly suggested the patch's own SHA and title
line rather than the referenced commit's. This fixes that.
Ironically this:
Fixes: bd17e036b495 ("checkpatch: warn for non-standard fixes tag style")
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Louis Peens <louis.peens@corigine.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Cc: Philippe Schenker <philippe.schenker@toradex.com>
Cc: Simon Horman <horms@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since nilfs2 has a ->writepages operation already, ->writepage is only
called by the migration code. If we add a ->migrate_folio operation, it
won't even be used for that and so it can be deleted.
[konishi.ryusuke@gmail.com: fixed panic by using buffer_migrate_folio_norefs]
Link: https://lkml.kernel.org/r/20241002150036.1339475-2-willy@infradead.org
Link: https://lkml.kernel.org/r/20241024092602.13395-10-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Regarding the cpfile, a metadata file that manages checkpoints, convert
the page-based implementation to a folio-based implementation.
This change involves some helper functions to calculate byte offsets on
folios and removing a few helper functions that are no longer needed.
Link: https://lkml.kernel.org/r/20241024092602.13395-9-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
All calls to nilfs_palloc_block_get_entry() are now gone, so remove it.
Link: https://lkml.kernel.org/r/20241024092602.13395-8-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Regarding the DAT, a metadata file that manages virtual block addresses,
convert the page-based implementation to a folio-based implementation.
Link: https://lkml.kernel.org/r/20241024092602.13395-7-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Convert the page-based implementation of ifile, a metadata file that
manages inodes, to folio-based.
Link: https://lkml.kernel.org/r/20241024092602.13395-6-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Regarding the persistent oject allocator, a common mechanism for
allocating objects in metadata files such as inodes and DAT entries,
convert the page-based implementation to a folio-based implementation.
In this conversion, helper functions nilfs_palloc_group_desc_offset() and
nilfs_palloc_bitmap_offset() are added and used to calculate the byte
offset within a folio of a group descriptor structure and bitmap,
respectively, to replace kmap_local_page with kmap_local_folio.
In addition, a helper function called nilfs_palloc_entry_offset() is
provided to facilitate common calculation of the byte offset within a
folio of metadata file entries managed in the persistent object allocator
format.
Link: https://lkml.kernel.org/r/20241024092602.13395-5-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
For the sufile, which is a metadata file that holds information about
managing segments, convert the page-based implementation to a folio-based
implementation.
kmap_local_page() is changed to use kmap_local_folio(), and where offsets
within a page are calculated using bh_offset(), are replaced with
calculations using offset_in_folio() with an additional helper function
nilfs_sufile_segment_usage_offset().
Link: https://lkml.kernel.org/r/20241024092602.13395-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In the common routines for metadata files, nilfs_mdt_insert_new_block(),
which inserts a new block buffer into the cache, is still page-based, and
there are two places where bh_offset() is used. Convert these to
page-based.
Link: https://lkml.kernel.org/r/20241024092602.13395-3-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "nilfs2: Finish folio conversion".
This series converts all remaining page structure references in nilfs2 to
folio-based, except for nilfs_copy_buffer function, which was converted to
use folios in advance for cross-fs page flags cleanup.
This prioritizes folio conversion, and does not include buffer head
reference reduction, nor does it support for block sizes larger than the
system page size.
The first eight patches in this series mainly convert each of the
nilfs2-specific metadata implementations to use folios. The last four
patches, by Matthew Wilcox, eliminate aops writepage callbacks and convert
the remaining page structure references to folio-based. This part
reflects some corrections to the patch series posted by Matthew.
This patch (of 12):
In the segment buffer (log buffer) implementation, two parts of the block
buffer, CRC calculation and bio preparation, are still page-based, so
convert them to folio-based.
Link: https://lkml.kernel.org/r/20241024092602.13395-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20241024092602.13395-2-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a new entry in the MAINTAINERS file for the min heap library code,
with myself as the maintainer. I am pleased to take on the responsibility
of maintaining and reviewing patches for this library, as I am
well-acquainted with its details through recent contributions.
Link: https://lkml.kernel.org/r/20241027004003.987934-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce an overview of the min heap API, detailing its usage and
functionality. The documentation aims to provide developers with a clear
understanding of how to implement and utilize min heaps within the Linux
kernel, enhancing the overall accessibility of this data structure.
Link: https://lkml.kernel.org/r/20241020040200.939973-11-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace the swp function pointer in the min_heap_callbacks of bcachefs
with NULL, allowing direct usage of the default builtin swap
implementation. This modification simplifies the code and improves
performance by removing unnecessary function indirection.
Link: https://lkml.kernel.org/r/20241020040200.939973-10-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Refactor the bcachefs code to remove multiple redundant declarations of
min_heap_callbacks, ensuring that each unique declaration appears only
once.
Link: https://lore.kernel.org/20241017095520.GV16066@noisy.programming.kicks-ass.net
Link: https://lkml.kernel.org/r/20241020040200.939973-9-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace the swp function pointer in the min_heap_callbacks of bcache with
NULL, allowing direct usage of the default builtin swap implementation.
This modification simplifies the code and improves performance by removing
unnecessary function indirection.
Link: https://lkml.kernel.org/r/20241020040200.939973-8-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace the swp function pointer in the min_heap_callbacks of dm-vdo with
NULL, allowing direct usage of the default builtin swap implementation.
This modification simplifies the code and improves performance by removing
unnecessary function indirection.
Link: https://lkml.kernel.org/r/20241020040200.939973-7-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After introducing the default builtin swap implementation, update the
min_heap_callbacks to replace the swp function pointer with NULL. This
change allows the min heap to directly utilize the builtin swap,
simplifying the code.
Link: https://lkml.kernel.org/r/20241020040200.939973-6-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace the swp function pointer in the min_heap_callbacks of
test_min_heap with NULL, allowing direct usage of the default builtin swap
implementation. This modification simplifies the code and improves
performance by removing unnecessary function indirection.
Link: https://lkml.kernel.org/r/20241020040200.939973-5-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The non-inline min heap API can result in an indirect function call to the
custom swap function. This becomes particularly costly when
CONFIG_MITIGATION_RETPOLINE is enabled, as indirect function calls are
expensive in this case.
To address this, copy the code from lib/sort.c and provide a default
builtin swap implementation that performs element swaps based on the
element size. This change allows most users to avoid the overhead of
indirect function calls, improving efficiency.
Link: https://lkml.kernel.org/r/20241020040200.939973-4-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Improve the efficiency of the min heap by prescaling counters, eliminating
the need to repeatedly compute 'index * element_size' when accessing
elements. By doing so, we avoid the overhead associated with
recalculating the byte offset for each heap operation.
However, with prescaling, the calculation for the parent element's
location is no longer as simple as '(i - 1) / 2'. To address this, we
copy the parent function from 'lib/sort.c', which calculates the parent
offset in a branchless manner without using any division instructions.
This optimization should result in a more efficient heap implementation by
reducing the computational overhead of finding parent and child offsets.
Link: https://lkml.kernel.org/r/20241020040200.939973-3-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Enhance min heap API with non-inline functions and
optimizations", v2.
Add non-inline versions of the min heap API functions in lib/min_heap.c
and updates all users outside of kernel/events/core.c to use these
non-inline versions. To mitigate the performance impact of indirect
function calls caused by the non-inline versions of the swap and compare
functions, a builtin swap has been introduced that swaps elements based on
their size. Additionally, it micro-optimizes the efficiency of the min
heap by pre-scaling the counter, following the same approach as in
lib/sort.c. Documentation for the min heap API has also been added to the
core-api section.
This patch (of 10):
All current min heap API functions are marked with '__always_inline'.
However, as the number of users increases, inlining these functions
everywhere leads to a increase in kernel size.
In performance-critical paths, such as when perf events are enabled and
min heap functions are called on every context switch, it is important to
retain the inline versions for optimal performance. To balance this, the
original inline functions are kept, and additional non-inline versions of
the functions have been added in lib/min_heap.c.
Link: https://lkml.kernel.org/r/20241020040200.939973-1-visitorckw@gmail.com
Link: https://lore.kernel.org/20240522161048.8d8bbc7b153b4ecd92c50666@linux-foundation.org
Link: https://lkml.kernel.org/r/20241020040200.939973-2-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce PERCPU_PTR() macro to cast the percpu pointer from the percpu
address space to a generic (kernel) address space. Use it in
per_cpu_ptr() and related SHIFT_PERCPU_PTR() macros.
Also remove common knowledge from SHIFT_PERCPU_PTR() comment, "weird cast"
is just a standard way to inform sparse of a cast from the percpu address
space to a generic address space.
Link: https://lkml.kernel.org/r/20241021080856.48746-2-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Merge VERIFY_PERCPU_PTR() into non-CONFIG_SMP per_cpu_ptr() to make macro
similar to CONFIG_SMP per_cpu_ptr(). This will allow a follow-up patch to
refactor common code to a macro.
No functional changes, non-CONFIG_SMP per_cpu_ptr() was the only user of
VERIFY_PERCPU_PTR().
Link: https://lkml.kernel.org/r/20241021080856.48746-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since there are no longer any header include differences between
lib/list_sort.c and tools/lib/list_sort.c, update the expected diff in
check-header_ignore_hunks accordingly.
Link: https://lkml.kernel.org/r/20241012042828.471614-4-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since lib/list_sort.c no longer requires ARRAY_SIZE() and memset(), the
includes for kernel.h, bug.h, and string.h have been removed. Similarly,
tools/lib/list_sort.c also does not need to include these headers, so they
have been removed as well.
Link: https://lkml.kernel.org/r/20241012042828.471614-3-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Remove unnecessary header includes from
{tools/}lib/list_sort.c".
Remove outdated and unnecessary header includes from lib/list_sort.c and
tools/lib/list_sort.c. Additionally, update the hunk exceptions checked
by check_headers.sh to reflect these changes.
This patch (of 3):
After commit 043b3f7b6388 ("lib/list_sort: simplify and remove
MAX_LIST_LENGTH_BITS"), list_sort.c no longer uses ARRAY_SIZE() (which
required kernel.h and bug.h for BUILD_BUG_ON_ZERO via __must_be_array) or
memset() (which required string.h). As these headers are no longer
needed, removes them.
There are no changes to the generated code, as confirmed by 'objdump -d'.
Additionally, 'wc -l' shows that the size of lib/.list_sort.o.cmd is
reduced from 259 lines to 101 lines.
Link: https://lkml.kernel.org/r/20241012042828.471614-1-visitorckw@gmail.com
Link: https://lkml.kernel.org/r/20241012042828.471614-2-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use ERR_PTR_PCPU() when returning error pointer in the percpu address
space. Use IS_ERR_PCPU() and PTR_ERR_PCPU() when returning the error
pointer from the percpu address space. These macros add intermediate cast
to unsigned long when switching named address spaces.
The patch will avoid future build errors due to pointer address space
mismatch with enabled strict percpu address space checks.
Link: https://lkml.kernel.org/r/20240924090813.1353586-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
decode_stacktrace.sh adds a trailing space at the end of the decoded stack
if the module is not set (in most of the lines), which makes the some
lines of the stack having trailing space and some others not.
Do not add an extra space at the end of the line if module is not set,
adding consistency in output formatting.
Link: https://lkml.kernel.org/r/20241014100213.1873611-1-leitao@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Elliot Berman <quic_eberman@quicinc.com>
Reviewed-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Cc: Bjorn Andersson <quic_bjorande@quicinc.com>
Cc: Luca Ceresoli <luca.ceresoli@bootlin.com>
Cc: Xiong Nandi <xndchn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, cpuset is the only user of the union-find implementation.
Compiling union-find in all configurations unnecessarily increases the
code size when building the kernel without cgroup support. Modify the
build system to compile union-find only when CONFIG_CPUSETS is enabled.
Link: https://lore.kernel.org/lkml/1ccd6411-5002-4574-bb8e-3e64bba6a757@redhat.com/
Link: https://lkml.kernel.org/r/20241011141214.87096-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Waiman Long <llong@redhat.com>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Xavier <xavier_qy@163.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add Kunit tests for the kernel's implementation of the standard CRC-16
algorithm (<linux/crc16.h>). The test data consists of 100
randomly-generated test cases, validated against a naive CRC-16
implementation.
This test follows roughly the same logic as lib/crc32test.c, but without
the performance measurements.
Link: https://lkml.kernel.org/r/20241012-crc16-kunit-v3-1-0ca75cb58ca9@lkcamp.dev
Signed-off-by: Vinicius Peixoto <vpeixoto@lkcamp.dev>
Co-developed-by: Enzo Bertoloti <ebertoloti@lkcamp.dev>
Signed-off-by: Enzo Bertoloti <ebertoloti@lkcamp.dev>
Co-developed-by: Fabricio Gasperin <fgasperin@lkcamp.dev>
Signed-off-by: Fabricio Gasperin <fgasperin@lkcamp.dev>
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Rae Moar <rmoar@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace the 'One' with 'On'.
Link: https://lkml.kernel.org/r/20241012100817.323007-1-sui.jingfeng@linux.dev
Fixes: af2880ec4402 ("scatterlist: add dedicated config for DMA flags")
Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Reviewed-by: Petr Tesarik <petr@tesarici.cz>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
