- 08 Sep, 2021 40 commits
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Andy Shevchenko authored
Rename bitmap_alloc() to bitmap_zalloc() in tools to follow the bitmap API in the kernel. No functional changes intended. Link: https://lkml.kernel.org/r/20210814211713.180533-14-yury.norov@gmail.comSigned-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
Yury Norov <yury.norov@gmail.com> Suggested-by:
Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by:
Jiri Olsa <jolsa@redhat.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexey Klimov <aklimov@redhat.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Fix all kernel-doc warnings in lib/iov_iter.c: lib/iov_iter.c:695: warning: Function parameter or member 'i' not described in '_copy_mc_to_iter' lib/iov_iter.c:695: warning: Excess function parameter 'iter' description in '_copy_mc_to_iter' lib/iov_iter.c:695: warning: No description found for return value of '_copy_mc_to_iter' lib/iov_iter.c:758: warning: Function parameter or member 'i' not described in '_copy_from_iter_flushcache' lib/iov_iter.c:758: warning: Excess function parameter 'iter' description in '_copy_from_iter_flushcache' lib/iov_iter.c:758: warning: No description found for return value of '_copy_from_iter_flushcache' Link: https://lkml.kernel.org/r/20210809051053.6531-1-rdunlap@infradead.orgSigned-off-by:
Randy Dunlap <rdunlap@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Randy Dunlap authored
Fix kernel-doc warnings in dump_stack.c: lib/dump_stack.c:97: warning: Function parameter or member 'log_lvl' not described in 'dump_stack_lvl' lib/dump_stack.c:97: warning: expecting prototype for dump_stack(). Prototype was for dump_stack_lvl() instead Link: https://lkml.kernel.org/r/20210809051643.17567-1-rdunlap@infradead.orgSigned-off-by:
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Daniel Latypov authored
This follows up commit ebd09577 ("lib/test: convert lib/test_list_sort.c to use KUnit"). Converting this test to KUnit makes the test a bit shorter, standardizes how it reports pass/fail, and adds an easier way to run the test [1]. Like ebd09577, this leaves the file and Kconfig option name the same, but slightly changes their dependencies (needs CONFIG_KUNIT). [1] Can be run via $ ./tools/testing/kunit/kunit.py run --kunitconfig /dev/stdin <<EOF CONFIG_KUNIT=y CONFIG_TEST_SORT=y EOF [11:30:27] Starting KUnit Kernel ... [11:30:30] ============================================================ [11:30:30] ======== [PASSED] lib_sort ======== [11:30:30] [PASSED] test_sort [11:30:30] ============================================================ [11:30:30] Testing complete. 1 tests run. 0 failed. 0 crashed. 0 skipped. [11:30:30] Elapsed time: 37.032s total, 0.001s configuring, 34.090s building, 0.000s running Note: this is the time it took after a `make mrproper`. With an incremental rebuild, this looks more like: [11:38:58] Elapsed time: 6.444s total, 0.001s configuring, 3.416s building, 0.000s running Since the test has no dependencies, it can also be run (with some other tests) with just: $ ./tools/testing/kunit/kunit.py run Link: https://lkml.kernel.org/r/20210715232441.1380885-1-dlatypov@google.comSigned-off-by:
Daniel Latypov <dlatypov@google.com> Cc: Pravin Shedge <pravin.shedge4linux@gmail.com> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: David Gow <davidgow@google.com> Signed-off-by:
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Geert Uytterhoeven authored
RATIONAL_KUNIT_TEST selects RATIONAL, thus enabling an optional feature the user may not want to have enabled. Fix this by making the test depend on RATIONAL instead. Link: https://lkml.kernel.org/r/20210706100945.3803694-3-geert@linux-m68k.org Fixes: b6c75c4a ("lib/math/rational: add Kunit test cases") Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Trent Piepho <tpiepho@gmail.com> Signed-off-by:
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Geert Uytterhoeven authored
Patch series "math: RATIONAL and RATIONAL_KUNIT_TEST improvements". This series makes the RATIONAL symbol tristate, so it is not forced builtin if all users are modular, and makes the RATIONAL_KUNIT_TEST depend on RATIONAL, to avoid enabling RATIONAL if there are no real users. This patch (of 2): All but one symbols that select RATIONAL are tristate, but RATIONAL itself is bool. Change it to tristate, so the rational fractions support code can be modular if no builtin code relies on it. Link: https://lkml.kernel.org/r/20210706100945.3803694-1-geert@linux-m68k.org Link: https://lkml.kernel.org/r/20210706100945.3803694-2-geert@linux-m68k.orgSigned-off-by:
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Nathan Chancellor authored
This should have been done with commit 91ed3ed0 ("MAINTAINERS: update ClangBuiltLinux IRC chat") but I did not realize it was in two separate spots. Link: https://lkml.kernel.org/r/20210825211823.6406-3-nathan@kernel.orgSigned-off-by:
Nathan Chancellor <nathan@kernel.org> Reviewed-by:
Nick Desaulniers <ndesaulniers@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Sami Tolvanen <samitolvanen@google.com> Signed-off-by:
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Nathan Chancellor authored
We are now at llvm@lists.linux.dev. Link: https://lkml.kernel.org/r/20210825211823.6406-2-nathan@kernel.orgSigned-off-by:
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Nathan Chancellor authored
We are now at llvm@lists.linux.dev. Link: https://lkml.kernel.org/r/20210825211823.6406-1-nathan@kernel.orgSigned-off-by:
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Pavel Skripkin authored
Syzbot reported shift-out-of-bounds bug in profile_init(). The problem was in incorrect prof_shift. Since prof_shift value comes from userspace we need to clamp this value into [0, BITS_PER_LONG -1] boundaries. Second possible shiht-out-of-bounds was found by Tetsuo: sample_step local variable in read_profile() had "unsigned int" type, but prof_shift allows to make a BITS_PER_LONG shift. So, to prevent possible shiht-out-of-bounds sample_step type was changed to "unsigned long". Also, "unsigned short int" will be sufficient for storing [0, BITS_PER_LONG] value, that's why there is no need for "unsigned long" prof_shift. Link: https://lkml.kernel.org/r/20210813140022.5011-1-paskripkin@gmail.com Fixes: 1da177e4 ("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+e68c89a9510c159d9684@syzkaller.appspotmail.com Suggested-by:
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by:
Pavel Skripkin <paskripkin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Yang Yang authored
Use rlimit() helper instead of manually writing whole chain from task to rlimit value. See patch "posix-cpu-timers: Use dedicated helper to access rlimit values". Link: https://lkml.kernel.org/r/20210728030822.524789-1-yang.yang29@zte.com.cnSigned-off-by:
Yang Yang <yang.yang29@zte.com.cn> Reported-by:
Zeal Robot <zealci@zte.com.cn> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: sh_def@163.com <sh_def@163.com> Cc: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by:
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Daniel Lezcano authored
HZ unit conversion macros are available in units.h, use them and remove the duplicate definition. Link: https://lkml.kernel.org/r/20210816114732.1834145-11-daniel.lezcano@linaro.orgSigned-off-by:
Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by:
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Daniel Lezcano authored
HZ unit conversion macros are available in units.h, use them and remove the duplicate definition. Link: https://lkml.kernel.org/r/20210816114732.1834145-10-daniel.lezcano@linaro.orgSigned-off-by:
Miquel Raynal <miquel.raynal@bootlin.com> Reviewed-by:
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Daniel Lezcano authored
HZ unit conversion macros are available in units.h, use them and remove the duplicate definition. Link: https://lkml.kernel.org/r/20210816114732.1834145-9-daniel.lezcano@linaro.orgSigned-off-by:
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Daniel Lezcano authored
HZ unit conversion macros are available in units.h, use them and remove the duplicate definition. Link: https://lkml.kernel.org/r/20210816114732.1834145-8-daniel.lezcano@linaro.orgSigned-off-by:
Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Christian Eggers <ceggers@arri.de> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Lukasz Luba <lukasz.luba@arm.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Peter Meerwald <pmeerw@pmeerw.net> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Zhang Rui <rui.zhang@intel.com> Signed-off-by:
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Daniel Lezcano authored
HZ unit conversion macros are available in units.h, use them and remove the duplicate definition. The new macro is an unsigned long. The code dealing with it is considering as an unsigned long also. Link: https://lkml.kernel.org/r/20210816114732.1834145-7-daniel.lezcano@linaro.orgSigned-off-by:
Christian Eggers <ceggers@arri.de> Reviewed-by:
Guenter Roeck <linux@roeck-us.net> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Lukasz Luba <lukasz.luba@arm.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Peter Meerwald <pmeerw@pmeerw.net> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Zhang Rui <rui.zhang@intel.com> Signed-off-by:
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Daniel Lezcano authored
HZ unit conversion macros are available in units.h, use them and remove the duplicate definition. Link: https://lkml.kernel.org/r/20210816114732.1834145-6-daniel.lezcano@linaro.orgSigned-off-by:
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Daniel Lezcano authored
HZ unit conversion macros are available in units.h, use them and remove the duplicate definition. The new macro has an unsigned long type. All the code is dealing with unsigned long and the code using the macro is doing a coercitive cast to unsigned long. Link: https://lkml.kernel.org/r/20210816114732.1834145-5-daniel.lezcano@linaro.orgSigned-off-by:
Chanwoo Choi <cw00.choi@samsung.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Lukasz Luba <lukasz.luba@arm.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Peter Meerwald <pmeerw@pmeerw.net> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Zhang Rui <rui.zhang@intel.com> Signed-off-by:
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Daniel Lezcano authored
HZ unit conversion macros are available in units.h, use them and remove the duplicate definition. The new macro uses a unsigned long type which is already the type in the current code via the 'freq' variable. Link: https://lkml.kernel.org/r/20210816114732.1834145-4-daniel.lezcano@linaro.orgSigned-off-by:
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Daniel Lezcano authored
The macros for the unit conversion for frequency are duplicated in different places. Provide these macros in the 'units' header, so they can be reused. Link: https://lkml.kernel.org/r/20210816114732.1834145-3-daniel.lezcano@linaro.orgSigned-off-by:
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Daniel Lezcano authored
Patch series "Add Hz macros", v3. There are multiple definitions of the HZ_PER_MHZ or HZ_PER_KHZ in the different drivers. Instead of duplicating this definition again and again, add one in the units.h header to be reused in all the place the redefiniton occurs. At the same time, change the type of the Watts, as they can not be negative. This patch (of 10): The users of the macros are safe to be assigned with an unsigned instead of signed as the variables using them are themselves unsigned. Link: https://lkml.kernel.org/r/20210816114732.1834145-1-daniel.lezcano@linaro.org Link: https://lkml.kernel.org/r/20210816114732.1834145-2-daniel.lezcano@linaro.orgSigned-off-by:
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Andy Shevchenko authored
Fix trivia typo Not -> Note in the comment to DO_ONCE(). Link: https://lkml.kernel.org/r/20210722184349.76290-1-andriy.shevchenko@linux.intel.comSigned-off-by:
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Colin Ian King authored
Threre is a spelling mistake in the Kconfig text. Fix it. Link: https://lkml.kernel.org/r/20210704095207.37342-1-colin.king@canonical.comSigned-off-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
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Ohhoon Kwon authored
While comm change event via prctl has been reported to proc connector by 'commit f786ecba ("connector: add comm change event report to proc connector")', connector listeners were missing comm changes by explicit writes on /proc/[pid]/comm. Let explicit writes on /proc/[pid]/comm report to proc connector. Link: https://lkml.kernel.org/r/20210701133458epcms1p68e9eb9bd0eee8903ba26679a37d9d960@epcms1p6Signed-off-by:
Ohhoon Kwon <ohoono.kwon@samsung.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Christoph Hellwig authored
Use seq_escape_str and seq_printf instead of poking holes into the seq_file abstraction. Link: https://lkml.kernel.org/r/20210810151945.1795567-1-hch@lst.deSigned-off-by:
Christoph Hellwig <hch@lst.de> Acked-by:
Christian Brauner <christian.brauner@ubuntu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Greg Kroah-Hartman authored
This is not needed by any modules, so remove the export. Link: https://lkml.kernel.org/r/20210722185814.504541-1-gregkh@linuxfoundation.orgSigned-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by:
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Randy Dunlap authored
Fix all kernel-doc warnings in arch/alpha/kernel/pci-sysfs.c: arch/alpha/kernel/pci-sysfs.c:67: warning: No description found for return value of 'pci_mmap_resource' arch/alpha/kernel/pci-sysfs.c:115: warning: Function parameter or member 'pdev' not described in 'pci_remove_resource_files' arch/alpha/kernel/pci-sysfs.c:115: warning: Excess function parameter 'dev' description in 'pci_remove_resource_files' arch/alpha/kernel/pci-sysfs.c:230: warning: Function parameter or member 'pdev' not described in 'pci_create_resource_files' arch/alpha/kernel/pci-sysfs.c:230: warning: Excess function parameter 'dev' description in 'pci_create_resource_files' arch/alpha/kernel/pci-sysfs.c:232: warning: No description found for return value of 'pci_create_resource_files' arch/alpha/kernel/pci-sysfs.c:305: warning: Function parameter or member 'bus' not described in 'pci_adjust_legacy_attr' arch/alpha/kernel/pci-sysfs.c:305: warning: Excess function parameter 'b' description in 'pci_adjust_legacy_attr' Link: https://lkml.kernel.org/r/20210808185249.31442-1-rdunlap@infradead.orgSigned-off-by:
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Randy Dunlap authored
Copy these macros from ia64/include/asm/agp.h to avoid the "empty-body" in 'if' statment warning. drivers/char/agp/generic.c: In function 'agp_generic_destroy_page': ../drivers/char/agp/generic.c:1265:42: warning: suggest braces around empty body in an 'if' statement [-Wempty-body] 1265 | unmap_page_from_agp(page); Link: https://lkml.kernel.org/r/20210809030822.20658-1-rdunlap@infradead.orgSigned-off-by:
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SeongJae Park authored
This commit updates MAINTAINERS file for DAMON related files. Link: https://lkml.kernel.org/r/20210716081449.22187-14-sj38.park@gmail.comSigned-off-by:
SeongJae Park <sjpark@amazon.de> Reviewed-by:
Markus Boehme <markubo@amazon.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Amit Shah <amit@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: David Woodhouse <dwmw@amazon.com> Cc: Fan Du <fan.du@intel.com> Cc: Fernand Sieber <sieberf@amazon.com> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Greg Thelen <gthelen@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leonard Foerster <foersleo@amazon.de> Cc: Marco Elver <elver@google.com> Cc: Maximilian Heyne <mheyne@amazon.de> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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SeongJae Park authored
This commit adds a simple user space tests for DAMON. The tests are using kselftest framework. Link: https://lkml.kernel.org/r/20210716081449.22187-13-sj38.park@gmail.comSigned-off-by:
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SeongJae Park authored
This commit adds kunit based unit tests for the core and the virtual address spaces monitoring primitives of DAMON. Link: https://lkml.kernel.org/r/20210716081449.22187-12-sj38.park@gmail.comSigned-off-by:
Brendan Higgins <brendanhiggins@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Amit Shah <amit@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: David Woodhouse <dwmw@amazon.com> Cc: Fan Du <fan.du@intel.com> Cc: Fernand Sieber <sieberf@amazon.com> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Greg Thelen <gthelen@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leonard Foerster <foersleo@amazon.de> Cc: Marco Elver <elver@google.com> Cc: Markus Boehme <markubo@amazon.de> Cc: Maximilian Heyne <mheyne@amazon.de> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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SeongJae Park authored
This commit adds documents for DAMON under `Documentation/admin-guide/mm/damon/` and `Documentation/vm/damon/`. Link: https://lkml.kernel.org/r/20210716081449.22187-11-sj38.park@gmail.comSigned-off-by:
Fernand Sieber <sieberf@amazon.com> Reviewed-by:
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SeongJae Park authored
In some use cases, users would want to run multiple monitoring context. For example, if a user wants a high precision monitoring and dedicating multiple CPUs for the job is ok, because DAMON creates one monitoring thread per one context, the user can split the monitoring target regions into multiple small regions and create one context for each region. Or, someone might want to simultaneously monitor different address spaces, e.g., both virtual address space and physical address space. The DAMON's API allows such usage, but 'damon-dbgfs' does not. Therefore, only kernel space DAMON users can do multiple contexts monitoring. This commit allows the user space DAMON users to use multiple contexts monitoring by introducing two new 'damon-dbgfs' debugfs files, 'mk_context' and 'rm_context'. Users can create a new monitoring context by writing the desired name of the new context to 'mk_context'. Then, a new directory with the name and having the files for setting of the context ('attrs', 'target_ids' and 'record') will be created under the debugfs directory. Writing the name of the context to remove to 'rm_context' will remove the related context and directory. Link: https://lkml.kernel.org/r/20210716081449.22187-10-sj38.park@gmail.comSigned-off-by: -
SeongJae Park authored
For CPU usage accounting, knowing pid of the monitoring thread could be helpful. For example, users could use cpuaccount cgroups with the pid. This commit therefore exports the pid of currently running monitoring thread to the user space via 'kdamond_pid' file in the debugfs directory. Link: https://lkml.kernel.org/r/20210716081449.22187-9-sj38.park@gmail.comSigned-off-by:
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SeongJae Park authored
DAMON is designed to be used by kernel space code such as the memory management subsystems, and therefore it provides only kernel space API. That said, letting the user space control DAMON could provide some benefits to them. For example, it will allow user space to analyze their specific workloads and make their own special optimizations. For such cases, this commit implements a simple DAMON application kernel module, namely 'damon-dbgfs', which merely wraps the DAMON api and exports those to the user space via the debugfs. 'damon-dbgfs' exports three files, ``attrs``, ``target_ids``, and ``monitor_on`` under its debugfs directory, ``<debugfs>/damon/``. Attributes ---------- Users can read and write the ``sampling interval``, ``aggregation interval``, ``regions update interval``, and min/max number of monitoring target regions by reading from and writing to the ``attrs`` file. For example, below commands set those values to 5 ms, 100 ms, 1,000 ms, 10, 1000 and check it again:: # cd <debugfs>/damon # echo 5000 100000 1000000 10 1000 > attrs # cat attrs 5000 100000 1000000 10 1000 Target IDs ---------- Some types of address spaces supports multiple monitoring target. For example, the virtual memory address spaces monitoring can have multiple processes as the monitoring targets. Users can set the targets by writing relevant id values of the targets to, and get the ids of the current targets by reading from the ``target_ids`` file. In case of the virtual address spaces monitoring, the values should be pids of the monitoring target processes. For example, below commands set processes having pids 42 and 4242 as the monitoring targets and check it again:: # cd <debugfs>/damon # echo 42 4242 > target_ids # cat target_ids 42 4242 Note that setting the target ids doesn't start the monitoring. Turning On/Off -------------- Setting the files as described above doesn't incur effect unless you explicitly start the monitoring. You can start, stop, and check the current status of the monitoring by writing to and reading from the ``monitor_on`` file. Writing ``on`` to the file starts the monitoring of the targets with the attributes. Writing ``off`` to the file stops those. DAMON also stops if every targets are invalidated (in case of the virtual memory monitoring, target processes are invalidated when terminated). Below example commands turn on, off, and check the status of DAMON:: # cd <debugfs>/damon # echo on > monitor_on # echo off > monitor_on # cat monitor_on off Please note that you cannot write to the above-mentioned debugfs files while the monitoring is turned on. If you write to the files while DAMON is running, an error code such as ``-EBUSY`` will be returned. [akpm@linux-foundation.org: remove unneeded "alloc failed" printks] [akpm@linux-foundation.org: replace macro with static inline] Link: https://lkml.kernel.org/r/20210716081449.22187-8-sj38.park@gmail.comSigned-off-by:Leonard Foerster <foersleo@amazon.de> Reviewed-by:
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SeongJae Park authored
This commit adds a tracepoint for DAMON. It traces the monitoring results of each region for each aggregation interval. Using this, DAMON can easily integrated with tracepoints supporting tools such as perf. Link: https://lkml.kernel.org/r/20210716081449.22187-7-sj38.park@gmail.comSigned-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by:
Shakeel Butt <shakeelb@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Amit Shah <amit@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: David Woodhouse <dwmw@amazon.com> Cc: Fan Du <fan.du@intel.com> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Greg Thelen <gthelen@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Marco Elver <elver@google.com> Cc: Markus Boehme <markubo@amazon.de> Cc: Maximilian Heyne <mheyne@amazon.de> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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SeongJae Park authored
This commit introduces a reference implementation of the address space specific low level primitives for the virtual address space, so that users of DAMON can easily monitor the data accesses on virtual address spaces of specific processes by simply configuring the implementation to be used by DAMON. The low level primitives for the fundamental access monitoring are defined in two parts: 1. Identification of the monitoring target address range for the address space. 2. Access check of specific address range in the target space. The reference implementation for the virtual address space does the works as below. PTE Accessed-bit Based Access Check ----------------------------------- The implementation uses PTE Accessed-bit for basic access checks. That is, it clears the bit for the next sampling target page and checks whether it is set again after one sampling period. This could disturb the reclaim logic. DAMON uses ``PG_idle`` and ``PG_young`` page flags to solve the conflict, as Idle page tracking does. VMA-based Target Address Range Construction ------------------------------------------- Only small parts in the super-huge virtual address space of the processes are mapped to physical memory and accessed. Thus, tracking the unmapped address regions is just wasteful. However, because DAMON can deal with some level of noise using the adaptive regions adjustment mechanism, tracking every mapping is not strictly required but could even incur a high overhead in some cases. That said, too huge unmapped areas inside the monitoring target should be removed to not take the time for the adaptive mechanism. For the reason, this implementation converts the complex mappings to three distinct regions that cover every mapped area of the address space. Also, the two gaps between the three regions are the two biggest unmapped areas in the given address space. The two biggest unmapped areas would be the gap between the heap and the uppermost mmap()-ed region, and the gap between the lowermost mmap()-ed region and the stack in most of the cases. Because these gaps are exceptionally huge in usual address spaces, excluding these will be sufficient to make a reasonable trade-off. Below shows this in detail:: <heap> <BIG UNMAPPED REGION 1> <uppermost mmap()-ed region> (small mmap()-ed regions and munmap()-ed regions) <lowermost mmap()-ed region> <BIG UNMAPPED REGION 2> <stack> [akpm@linux-foundation.org: mm/damon/vaddr.c needs highmem.h for kunmap_atomic()] [sjpark@amazon.de: remove unnecessary PAGE_EXTENSION setup] Link: https://lkml.kernel.org/r/20210806095153.6444-2-sj38.park@gmail.com [sjpark@amazon.de: safely walk page table] Link: https://lkml.kernel.org/r/20210831161800.29419-1-sj38.park@gmail.com Link: https://lkml.kernel.org/r/20210716081449.22187-6-sj38.park@gmail.comSigned-off-by: -
SeongJae Park authored
PG_idle and PG_young allow the two PTE Accessed bit users, Idle Page Tracking and the reclaim logic concurrently work while not interfering with each other. That is, when they need to clear the Accessed bit, they set PG_young to represent the previous state of the bit, respectively. And when they need to read the bit, if the bit is cleared, they further read the PG_young to know whether the other has cleared the bit meanwhile or not. For yet another user of the PTE Accessed bit, we could add another page flag, or extend the mechanism to use the flags. For the DAMON usecase, however, we don't need to do that just yet. IDLE_PAGE_TRACKING and DAMON are mutually exclusive, so there's only ever going to be one user of the current set of flags. In this commit, we split out the CONFIG options to allow for the use of PG_young and PG_idle outside of idle page tracking. In the next commit, DAMON's reference implementation of the virtual memory address space monitoring primitives will use it. [sjpark@amazon.de: set PAGE_EXTENSION for non-64BIT] Link: https://lkml.kernel.org/r/20210806095153.6444-1-sj38.park@gmail.com [akpm@linux-foundation.org: tweak Kconfig text] [sjpark@amazon.de: hide PAGE_IDLE_FLAG from users] Link: https://lkml.kernel.org/r/20210813081238.34705-1-sj38.park@gmail.com Link: https://lkml.kernel.org/r/20210716081449.22187-5-sj38.park@gmail.comSigned-off-by:
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SeongJae Park authored
Even somehow the initial monitoring target regions are well constructed to fulfill the assumption (pages in same region have similar access frequencies), the data access pattern can be dynamically changed. This will result in low monitoring quality. To keep the assumption as much as possible, DAMON adaptively merges and splits each region based on their access frequency. For each ``aggregation interval``, it compares the access frequencies of adjacent regions and merges those if the frequency difference is small. Then, after it reports and clears the aggregated access frequency of each region, it splits each region into two or three regions if the total number of regions will not exceed the user-specified maximum number of regions after the split. In this way, DAMON provides its best-effort quality and minimal overhead while keeping the upper-bound overhead that users set. Link: https://lkml.kernel.org/r/20210716081449.22187-4-sj38.park@gmail.comSigned-off-by:
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SeongJae Park authored
To avoid the unbounded increase of the overhead, DAMON groups adjacent pages that are assumed to have the same access frequencies into a region. As long as the assumption (pages in a region have the same access frequencies) is kept, only one page in the region is required to be checked. Thus, for each ``sampling interval``, 1. the 'prepare_access_checks' primitive picks one page in each region, 2. waits for one ``sampling interval``, 3. checks whether the page is accessed meanwhile, and 4. increases the access count of the region if so. Therefore, the monitoring overhead is controllable by adjusting the number of regions. DAMON allows both the underlying primitives and user callbacks to adjust regions for the trade-off. In other words, this commit makes DAMON to use not only time-based sampling but also space-based sampling. This scheme, however, cannot preserve the quality of the output if the assumption is not guaranteed. Next commit will address this problem. Link: https://lkml.kernel.org/r/20210716081449.22187-3-sj38.park@gmail.comSigned-off-by:
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