The addition of an if statement in lib/sort to handle the final unsorted 2
or 3 elements is not covered by existing test cases, leading to incomplete
test coverage. To ensure comprehensive testing and maintain 100% code
coverage, add a new testcase for scenarios where the if statement is
triggered.
Since the if statement is only triggered when the array length is odd and
the first element is greater than the second element, a testcase is
created using an array length of TEST_LEN - 1 and a suitable random seed
to maintain full code coverage.
Link: https://lkml.kernel.org/r/20240527203011.1644280-5-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After building the heap, the code continuously pops two elements from the
heap until only 2 or 3 elements remain, at which point it switches back to
a regular heapsort with one element popped at a time. However, to handle
the final 2 or 3 elements, an additional else-if statement in the while
loop was introduced, potentially increasing branch misses. Moreover, when
there are only 2 or 3 elements left, continuing with regular heapify
operations is unnecessary as these cases are simple enough to be handled
with a single comparison and 1 or 2 swaps outside the while loop.
Eliminating the additional else-if statement and directly managing cases
involving 2 or 3 elements outside the loop reduces unnecessary conditional
branches resulting from the numerous loops and conditionals in heapify.
This optimization maintains consistent numbers of comparisons and swaps
for arrays with even lengths while reducing swaps and comparisons for
arrays with odd lengths from 2.5 swaps and 1 comparison to 1.5 swaps and 1
comparison.
Link: https://lkml.kernel.org/r/20240527203011.1644280-4-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The existing comment in lib/sort refers to glibc qsort() using quicksort.
However, glibc qsort() no longer uses quicksort; it now uses mergesort and
falls back to heapsort if memory allocation for mergesort fails. This
makes the comment outdated and incorrect.
Update the comment to refer to quicksort in general rather than glibc's
implementation to provide accurate information about the comparisons and
trade-offs without implying an outdated implementation.
Link: https://lkml.kernel.org/r/20240527203011.1644280-3-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "lib/sort: Optimizations and cleanups".
This patch series optimizes the handling of the last 2 or 3 elements in
lib/sort and adds a testcase in lib/test_sort to maintain 100% code
coverage reflecting this change. Additionally, it corrects outdated
descriptions regarding glibc qsort() and removes the unused pr_fmt macro.
This patch (of 4):
The pr_fmt macro is defined but not used in lib/sort.c. Since there are
no pr_* functions printing any messages, the pr_fmt macro is redundant and
can be safely removed.
Link: https://lkml.kernel.org/r/20240527203011.1644280-1-visitorckw@gmail.com
Link: https://lkml.kernel.org/r/20240527203011.1644280-2-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sometimes there are special characters around module names in stack
traces, such as ARM32 with BACKTRACE_VERBOSE in "(%pS)" format, such as:
[<806e4845>] (dump_stack_lvl) from [<7f806013>] (hello_init+0x13/0x1000
[test])
In this case, $module will be "[test])", the trace can be decoded by
stripping the right parenthesis first: (dump_stack_lvl) from hello_init
(/foo/test.c:10) test.
Link: https://lkml.kernel.org/r/20240524042600.14738-3-xndchn@gmail.com
Signed-off-by: Xiong Nandi <xndchn@gmail.com>
Suggested-by: Elliot Berman <quic_eberman@quicinc.com>
Cc: Bjorn Andersson <quic_bjorande@quicinc.com>
Cc: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull i2c fixes from Wolfram Sang:
"The core gains placeholders for recently added functions when
CONFIG_I2C is not defined as well documentation fixes to start using
inclusive terminology.
The drivers get paths in DT bindings fixed as well as proper interrupt
handling for the ocores driver"
* tag 'i2c-for-6.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
docs: i2c: summary: be clearer with 'controller/target' and 'adapter/client' pairs
docs: i2c: summary: document 'local' and 'remote' targets
docs: i2c: summary: document use of inclusive language
docs: i2c: summary: update speed mode description
docs: i2c: summary: update I2C specification link
docs: i2c: summary: start sentences consistently.
i2c: Add nop fwnode operations
i2c: ocores: set IACK bit after core is enabled
dt-bindings: i2c: google,cros-ec-i2c-tunnel: correct path to i2c-controller schema
dt-bindings: i2c: atmel,at91sam: correct path to i2c-controller schema
Pull smb client fixes from Steve French:
"Five smb3 client fixes
- three nets/fiolios cifs fixes
- fix typo in module parameters description
- fix incorrect swap warning"
* tag '6.10-rc4-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: Move the 'pid' from the subreq to the req
cifs: Only pick a channel once per read request
cifs: Defer read completion
cifs: fix typo in module parameter enable_gcm_256
cifs: drop the incorrect assertion in cifs_swap_rw()
Pull memblock fix from Mike Rapoport:
"Fix fragility in checks for unset node ID.
Use numa_valid_node() function to verify that nid is a valid node
ID instead of inconsistent comparisons with either NUMA_NO_NODE or
MAX_NUMNODES"
* tag 'fixes-2024-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
memblock: use numa_valid_node() helper to check for invalid node ID
Pull MIPS fixes from Thomas Bogendoerfer:
- fix lseek in o32 compat mode
- fix for microMIPS MT ASE helpers
* tag 'mips-fixes_6.10_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
mips: fix compat_sys_lseek syscall
MIPS: mipsmtregs: Fix target register for MFTC0
Pull x86 fixes from Borislav Petkov:
- An ARM-relevant fix to not free default RMIDs of a resource control
group
- A randconfig build fix for the VMware virtual GPU driver
* tag 'x86_urgent_for_v6.10_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Don't try to free nonexistent RMIDs
drm/vmwgfx: Fix missing HYPERVISOR_GUEST dependency
Pull powerpc fixes from Michael Ellerman:
- Prevent use-after-free in 64-bit KVM VFIO
- Add generated Power8 crypto asm to .gitignore
Thanks to Al Viro and Nathan Lynch.
* tag 'powerpc-6.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()
powerpc/crypto: Add generated P8 asm to .gitignore
This pull request fixes the paths of the dt-schema to their
complete locations for the ChromeOS EC tunnel driver and the
Atmel at91sam drivers.
Additionally, the OpenCores driver receives a fix for an issue
that dates back to version 2.6.18. Specifically, the interrupts
need to be acknowledged (clearing all pending interrupts) after
enabling the core.
Pull rust fix from Miguel Ojeda:
- Avoid unused import warning in 'rusttest'.
* tag 'rust-fixes-6.10' of https://github.com/Rust-for-Linux/linux:
rust: avoid unused import warning in `rusttest`
Pull regulator fixes from Mark Brown:
"A few driver specific fixes for incorrect device descriptions, plus a
fix for a missing symbol export which causes build failures for some
newly added drivers in other trees"
* tag 'regulator-fix-v6.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: axp20x: AXP717: fix LDO supply rails and off-by-ones
regulator: bd71815: fix ramp values
regulator: core: Fix modpost error "regulator_get_regmap" undefined
regulator: tps6594-regulator: Fix the number of irqs for TPS65224 and TPS6594
Pull spi fixes from Mark Brown:
"A number of fixes that have built up for SPI, a bunch of driver
specific ones including an unfortunate revert of an optimisation for
the i.MX driver which was causing issues with some configurations,
plus a couple of core fixes for the rarely used octal mode and for a
bad interaction between multi-CS support and target mode"
* tag 'spi-fix-v6.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: spi-imx: imx51: revert burst length calculation back to bits_per_word
spi: Fix SPI slave probe failure
spi: Fix OCTAL mode support
spi: stm32: qspi: Clamp stm32_qspi_get_mode() output to CCR_BUSWIDTH_4
spi: stm32: qspi: Fix dual flash mode sanity test in stm32_qspi_setup()
spi: cs42l43: Drop cs35l56 SPI speed down to 11MHz
spi: cs42l43: Correct SPI root clock speed
Pull nfsd fixes from Chuck Lever:
- Fix crashes triggered by administrative operations on the server
* tag 'nfsd-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
NFSD: grab nfsd_mutex in nfsd_nl_rpc_status_get_dumpit()
nfsd: fix oops when reading pool_stats before server is started
Pull xfs fix from Chandan Babu:
- Fix assertion failure due to a race between unlink and cluster buffer
instantiation.
* tag 'xfs-6.10-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix unlink vs cluster buffer instantiation race
Pull bcachefs fixes from Kent Overstreet:
"Lots of (mostly boring) fixes for syzbot bugs and rare(r) CI bugs.
The LRU_TIME_BITS fix was slightly more involved; we only have 48 bits
for the LRU position (we would prefer 64), so wraparound is possible
for the cached data LRUs on a filesystem that has done sufficient
(petabytes) reads; this is now handled.
One notable user reported bugfix, where we were forgetting to
correctly set the bucket data type, which should have been
BCH_DATA_need_gc_gens instead of BCH_DATA_free; this was causing us to
go emergency read-only on a filesystem that had seen heavy enough use
to see bucket gen wraparoud.
We're now starting to fix simple (safe) errors without requiring user
intervention - i.e. a small incremental step towards full self
healing.
This is currently limited to just certain allocation information
counters, and the error is still logged in the superblock; see that
patch for more information. ("bcachefs: Fix safe errors by default")"
* tag 'bcachefs-2024-06-22' of https://evilpiepirate.org/git/bcachefs: (22 commits)
bcachefs: Move the ei_flags setting to after initialization
bcachefs: Fix a UAF after write_super()
bcachefs: Use bch2_print_string_as_lines for long err
bcachefs: Fix I_NEW warning in race path in bch2_inode_insert()
bcachefs: Replace bare EEXIST with private error codes
bcachefs: Fix missing alloc_data_type_set()
closures: Change BUG_ON() to WARN_ON()
bcachefs: fix alignment of VMA for memory mapped files on THP
bcachefs: Fix safe errors by default
bcachefs: Fix bch2_trans_put()
bcachefs: set_worker_desc() for delete_dead_snapshots
bcachefs: Fix bch2_sb_downgrade_update()
bcachefs: Handle cached data LRU wraparound
bcachefs: Guard against overflowing LRU_TIME_BITS
bcachefs: delete_dead_snapshots() doesn't need to go RW
bcachefs: Fix early init error path in journal code
bcachefs: Check for invalid btree IDs
bcachefs: Fix btree ID bitmasks
bcachefs: Fix shift overflow in read_one_super()
bcachefs: Fix a locking bug in the do_discard_fast() path
...
Pull ata fix from Niklas Cassel:
- We currently enable DIPM (device initiated power management) in the
device (using a SET FEATURES call to the device), regardless if the
HBA supports any LPM states or not. It seems counter intuitive, and
potentially dangerous to enable a device side feature, when the HBA
does not have the corresponding support. Thus, make sure that we do
not enable DIPM if the HBA does not support any LPM states.
* tag 'ata-6.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
ata: ahci: Do not enable LPM if no LPM states are supported by the HBA
Pull pwm fixes from Uwe Kleine-König:
"Three fixes for the pwm-stm32 driver.
The first patch prevents an integer wrap-around for small periods. In
the second patch the calculation of the prescaler is fixed which
resulted in values for the ARR register that don't fit into the
corresponding register bit field. The last commit improves an error
message that was wrongly copied from another error path"
* tag 'pwm/for-6.10-rc5-fixes-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux:
pwm: stm32: Fix error message to not describe the previous error path
pwm: stm32: Fix calculation of prescaler
pwm: stm32: Refuse too small period requests
Pull SoC fixes from Arnd Bergmann:
"There are seven oneline patches that each address a distinct problem
on the NXP i.MX platform, mostly the popular i.MX8M variant.
The only other two fixes are for error handling on the psci firmware
driver and SD card support on the milkv duo riscv board"
* tag 'arm-fixes-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
firmware: psci: Fix return value from psci_system_suspend()
riscv: dts: sophgo: disable write-protection for milkv duo
arm64: dts: imx8qm-mek: fix gpio number for reg_usdhc2_vmmc
arm64: dts: freescale: imx8mm-verdin: enable hysteresis on slow input pin
arm64: dts: imx93-11x11-evk: Remove the 'no-sdio' property
arm64: dts: freescale: imx8mp-venice-gw73xx-2x: fix BT shutdown GPIO
arm: dts: imx53-qsb-hdmi: Disable panel instead of deleting node
arm64: dts: imx8mp: Fix TC9595 input clock on DH i.MX8M Plus DHCOM SoM
arm64: dts: freescale: imx8mm-verdin: Fix GPU speed
