Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
code
Clone this repository
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Pull turbostat updates from Len Brown:
- Fix regression that affinitized forked child in one-shot mode.
- Harden one-shot mode against hotplug online/offline
- Enable RAPL SysWatt column by default
- Add initial PTL, CWF platform support
- Harden initial PMT code in response to early use
- Enable first built-in PMT counter: CWF c1e residency
- Refuse to run on unsupported platforms without --force, to encourage
updating to a version that supports the system, and to avoid
no-so-useful measurement results
* tag 'turbostat-2025.02.02' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: (25 commits)
tools/power turbostat: version 2025.02.02
tools/power turbostat: Add CPU%c1e BIC for CWF
tools/power turbostat: Harden one-shot mode against cpu offline
tools/power turbostat: Fix forked child affinity regression
tools/power turbostat: Add tcore clock PMT type
tools/power turbostat: version 2025.01.14
tools/power turbostat: Allow adding PMT counters directly by sysfs path
tools/power turbostat: Allow mapping multiple PMT files with the same GUID
tools/power turbostat: Add PMT directory iterator helper
tools/power turbostat: Extend PMT identification with a sequence number
tools/power turbostat: Return default value for unmapped PMT domains
tools/power turbostat: Check for non-zero value when MSR probing
tools/power turbostat: Enhance turbostat self-performance visibility
tools/power turbostat: Add fixed RAPL PSYS divisor for SPR
tools/power turbostat: Fix PMT mmaped file size rounding
tools/power turbostat: Remove SysWatt from DISABLED_BY_DEFAULT
tools/power turbostat: Add an NMI column
tools/power turbostat: add Busy% to "show idle"
tools/power turbostat: Introduce --force parameter
tools/power turbostat: Improve --help output
...
Pull sh updates from John Paul Adrian Glaubitz:
"Fixes and improvements for sh:
- replace seq_printf() with the more efficient
seq_put_decimal_ull_width() to increase performance when stress
reading /proc/interrupts (David Wang)
- migrate sh to the generic rule for built-in DTB to help avoid race
conditions during parallel builds which can occur because Kbuild
decends into arch/*/boot/dts twice (Masahiro Yamada)
- replace select with imply in the board Kconfig for enabling
hardware with complex dependencies. This addresses warnings which
were reported by the kernel test robot (Geert Uytterhoeven)"
* tag 'sh-for-v6.14-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux:
sh: boards: Use imply to enable hardware with complex dependencies
sh: Migrate to the generic rule for built-in DTB
sh: irq: Use seq_put_decimal_ull_width() for decimal values
Summary of Changes since 2024.11.30:
Fix regression in 2023.11.07 that affinitized forked child
in one-shot mode.
Harden one-shot mode against hotplug online/offline
Enable RAPL SysWatt column by default.
Add initial PTL, CWF platform support.
Harden initial PMT code in response to early use.
Enable first built-in PMT counter: CWF c1e residency
Refuse to run on unsupported platforms without --force,
to encourage updating to a version that supports the system,
and to avoid no-so-useful measurement results.
Signed-off-by: Len Brown <len.brown@intel.com>
Pull misc vfs cleanups from Al Viro:
"Two unrelated patches - one is a removal of long-obsolete include in
overlayfs (it used to need fs/internal.h, but the extern it wanted has
been moved back to include/linux/namei.h) and another introduces
convenience helper constructing struct qstr by a NUL-terminated
string"
* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
add a string-to-qstr constructor
fs/overlayfs/namei.c: get rid of include ../internal.h
If CONFIG_I2C=n:
WARNING: unmet direct dependencies detected for SND_SOC_AK4642
Depends on [n]: SOUND [=y] && SND [=y] && SND_SOC [=y] && I2C [=n]
Selected by [y]:
- SH_7724_SOLUTION_ENGINE [=y] && CPU_SUBTYPE_SH7724 [=y] && SND_SIMPLE_CARD [=y]
WARNING: unmet direct dependencies detected for SND_SOC_DA7210
Depends on [n]: SOUND [=y] && SND [=y] && SND_SOC [=y] && SND_SOC_I2C_AND_SPI [=n]
Selected by [y]:
- SH_ECOVEC [=y] && CPU_SUBTYPE_SH7724 [=y] && SND_SIMPLE_CARD [=y]
Fix this by replacing select by imply, instead of adding a dependency on
I2C.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501240836.OvXqmANX-lkp@intel.com/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Intel Clearwater Forest report PMT telemetry with GUID 0x14421519, which
can be used to obtain module c1e residency counter of type tcore clock.
Add early support for the counter by using heuristic that should work
for the Clearwater Forest platforms.
Signed-off-by: Patryk Wlazlyn <patryk.wlazlyn@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Pull MIPS fix from Thomas Bogendoerfer:
"Revert commit breaking sysv ipc for o32 ABI"
* tag 'mips_6.14_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
Revert "mips: fix shmctl/semctl/msgctl syscall for o32"
Quite a few places want to build a struct qstr by given string;
it would be convenient to have a primitive doing that, rather
than open-coding it via QSTR_INIT().
The closest approximation was in bcachefs, but that expands to
initializer list - {.len = strlen(string), .name = string}.
It would be more useful to have it as compound literal -
(struct qstr){.len = strlen(string), .name = string}.
Unlike initializer list it's a valid expression. What's more,
it's a valid lvalue - it's an equivalent of anonymous local
variable with such initializer, so the things like
path->dentry = d_alloc_pseudo(mnt->mnt_sb, &QSTR(name));
are valid. It can also be used as initializer, with identical
effect -
struct qstr x = (struct qstr){.name = s, .len = strlen(s)};
is equivalent to
struct qstr anon_variable = {.name = s, .len = strlen(s)};
struct qstr x = anon_variable;
// anon_variable is never used after that point
and any even remotely sane compiler will manage to collapse that
into
struct qstr x = {.name = s, .len = strlen(s)};
What compound literals can't be used for is initialization of
global variables, but those are covered by QSTR_INIT().
This commit lifts definition(s) of QSTR() into linux/dcache.h,
converts it to compound literal (all bcachefs users are fine
with that) and converts assorted open-coded instances to using
that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 654102df2ac2 ("kbuild: add generic support for built-in
boot DTBs") introduced generic support for built-in DTBs.
Select GENERIC_BUILTIN_DTB when built-in DTB support is enabled.
To keep consistency across architectures, this commit also renames
CONFIG_USE_BUILTIN_DTB to CONFIG_BUILTIN_DTB, and
CONFIG_BUILTIN_DTB_SOURCE to CONFIG_BUILTIN_DTB_NAME.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
when turbostat interval mode can't migrate to a CPU, it complains,
prints no data, re-initializes with the new CPU configuration
and starts a new interval.
But this strategy in the face of a CPU hotplug offline during an interval
doesn't help in one-shot mode. When the missing CPU is discovered
at the end of the interval, the forked program has already returned
and there is nothing left for a new interval to measure.
So instead of aborting get_coutners() and delta_cpu() if a missing CPU
is detected, complain, but carry on and output what statistics are
actually present.
Use the same strategy for delta_cpu when aperf:mperf are observed
to have been reset -- complain, but carry on and print data for
the CPUs that are still present.
Interval mode error handling is unchanged.
One-shot mode can now do this:
$ sudo chcpu -e 1 ; sudo ./turbostat --quiet --show PkgWatt,Busy%,CPU chcpu -d 1
CPU 1 enabled
CPU 1 disabled
get_counters: Could not migrate to CPU 1
./turbostat: Counter reset detected
0.036920 sec
CPU Busy% PkgWatt
- 0.00 10.00
0 99.73 10.00
1 0.00
2 91.53
3 16.83
Suggested-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Pull more smb client updates from Steve French:
- various updates for special file handling: symlink handling,
support for creating sockets, cleanups, new mount options (e.g. to
allow disabling using reparse points for them, and to allow
overriding the way symlinks are saved), and fixes to error paths
- fix for kerberos mounts (allow IAKerb)
- SMB1 fix for stat and for setting SACL (auditing)
- fix an incorrect error code mapping
- cleanups"
* tag 'v6.14-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6: (21 commits)
cifs: Fix parsing native symlinks directory/file type
cifs: update internal version number
cifs: Add support for creating WSL-style symlinks
smb3: add support for IAKerb
cifs: Fix struct FILE_ALL_INFO
cifs: Add support for creating NFS-style symlinks
cifs: Add support for creating native Windows sockets
cifs: Add mount option -o reparse=none
cifs: Add mount option -o symlink= for choosing symlink create type
cifs: Fix creating and resolving absolute NT-style symlinks
cifs: Simplify reparse point check in cifs_query_path_info() function
cifs: Remove symlink member from cifs_open_info_data union
cifs: Update description about ACL permissions
cifs: Rename struct reparse_posix_data to reparse_nfs_data_buffer and move to common/smb2pdu.h
cifs: Remove struct reparse_posix_data from struct cifs_open_info_data
cifs: Remove unicode parameter from parse_reparse_point() function
cifs: Fix getting and setting SACLs over SMB1
cifs: Remove intermediate object of failed create SFU call
cifs: Validate EAs for WSL reparse points
cifs: Change translation of STATUS_PRIVILEGE_NOT_HELD to -EPERM
...
This reverts commit bc7584e009c39375294794f7ca751a6b2622c425.
The split IPC system calls for o32 have been introduced with modern
version only. Changing this breaks ABI.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Added for the sake of vfs_path_lookup(), which is in linux/namei.h
these days.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
On a system with n CPUs and m interrupts, there will be n*m decimal
values yielded via seq_printf(.."%10u "..) which has significant costs
parsing format string and is less efficient than seq_put_decimal_ull_width().
Stress reading /proc/interrupts indicates ~30% performance improvement with
this patch.
Signed-off-by: David Wang <00107082@163.com>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
In "one-shot" mode, turbostat
1. takes a counter snapshot
2. forks and waits for a child
3. takes the end counter snapshot and prints the result.
But turbostat counter snapshots currently use affinity to travel
around the system so that counter reads are "local", and this
affinity must be cleared between #1 and #2 above.
The offending commit removed that reset that allowed the child
to run on cpu_present_set.
Fix that issue, and improve upon the original by using
cpu_possible_set for the child. This allows the child
to also run on CPUs that hotplug online during its runtime.
Reported-by: Zhang Rui <rui.zhang@intel.com>
Fixes: 7bb3fe27ad4f ("tools/power/turbostat: Obey allowed CPUs during startup")
Signed-off-by: Len Brown <len.brown@intel.com>
Pull debugfs fix from Greg KH:
"Here is a single debugfs fix from Al to resolve a reported regression
in the driver-core tree. It has been reported to fix the issue"
* tag 'driver-core-6.14-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
debugfs: Fix the missing initializations in __debugfs_file_get()