September 2020 - Linux-kselftest-mirror

[PATCH] Documentation: kunit: Add naming guidelines

by David Gow

As discussed in [1], KUnit tests have hitherto not had a particularly consistent naming scheme. This adds documentation outlining how tests and test suites should be named, including how those names should be used in Kconfig entries and filenames. [1]: https://lore.kernel.org/linux-kselftest/202006141005.BA19A9D3@keescook/t/#u Signed-off-by: David Gow <davidgow(a)google.com> Reviewed-by: Kees Cook <keescook(a)chromium.org> --- This is a follow-up v1 to the RFC patch here: https://lore.kernel.org/linux-kselftest/20200620054944.167330-1-davidgow@go… There weren't any fundamental objections to the naming guidelines themselves, so nothing's changed on that front. Otherwise, changes since the RFC: - Fixed a bit of space/tab confusion in the index (Thanks, Randy) - Added some more examples (and some test case examples). - Added some examples of what not to call subsystems and suites. - No longer explicitly require "If unsure, put N" in Kconfig entries. - Minor formatting changes. Cheers, -- David Documentation/dev-tools/kunit/index.rst | 1 + Documentation/dev-tools/kunit/style.rst | 181 ++++++++++++++++++++++++ 2 files changed, 182 insertions(+) create mode 100644 Documentation/dev-tools/kunit/style.rst diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst index e93606ecfb01..c234a3ab3c34 100644 --- a/Documentation/dev-tools/kunit/index.rst +++ b/Documentation/dev-tools/kunit/index.rst @@ -11,6 +11,7 @@ KUnit - Unit Testing for the Linux Kernel usage kunit-tool api/index + style faq What is KUnit? diff --git a/Documentation/dev-tools/kunit/style.rst b/Documentation/dev-tools/kunit/style.rst new file mode 100644 index 000000000000..8cad2627924c --- /dev/null +++ b/Documentation/dev-tools/kunit/style.rst @@ -0,0 +1,181 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=========================== +Test Style and Nomenclature +=========================== + +Subsystems, Suites, and Tests +============================= + +In order to make tests as easy to find as possible, they're grouped into suites +and subsystems. A test suite is a group of tests which test a related area of +the kernel, and a subsystem is a set of test suites which test different parts +of the same kernel subsystem or driver. + +Subsystems +---------- + +Every test suite must belong to a subsystem. A subsystem is a collection of one +or more KUnit test suites which test the same driver or part of the kernel. A +rule of thumb is that a test subsystem should match a single kernel module. If +the code being tested can't be compiled as a module, in many cases the subsystem +should correspond to a directory in the source tree or an entry in the +MAINTAINERS file. If unsure, follow the conventions set by tests in similar +areas. + +Test subsystems should be named after the code being tested, either after the +module (wherever possible), or after the directory or files being tested. Test +subsystems should be named to avoid ambiguity where necessary. + +If a test subsystem name has multiple components, they should be separated by +underscores. *Do not* include "test" or "kunit" directly in the subsystem name +unless you are actually testing other tests or the kunit framework itself. + +Example subsystems could be: + +``ext4`` + Matches the module and filesystem name. +``apparmor`` + Matches the module name and LSM name. +``kasan`` + Common name for the tool, prominent part of the path ``mm/kasan`` +``snd_hda_codec_hdmi`` + Has several components (``snd``, ``hda``, ``codec``, ``hdmi``) separated by + underscores. Matches the module name. + +Avoid names like these: + +``linear-ranges`` + Names should use underscores, not dashes, to separate words. Prefer + ``linear_ranges``. +``qos-kunit-test`` + As well as using underscores, this name should not have "kunit-test" as a + suffix, and ``qos`` is ambiguous as a subsystem name. ``power_qos`` would be a + better name. +``pc_parallel_port`` + The corresponding module name is ``parport_pc``, so this subsystem should also + be named ``parport_pc``. + +.. note:: + The KUnit API and tools do not explicitly know about subsystems. They're + simply a way of categorising test suites and naming modules which + provides a simple, consistent way for humans to find and run tests. This + may change in the future, though. + +Suites +------ + +KUnit tests are grouped into test suites, which cover a specific area of +functionality being tested. Test suites can have shared initialisation and +shutdown code which is run for all tests in the suite. +Not all subsystems will need to be split into multiple test suites (e.g. simple drivers). + +Test suites are named after the subsystem they are part of. If a subsystem +contains several suites, the specific area under test should be appended to the +subsystem name, separated by an underscore. + +The full test suite name (including the subsystem name) should be specified as +the ``.name`` member of the ``kunit_suite`` struct, and forms the base for the +module name (see below). + +Example test suites could include: + +``ext4_inode`` + Part of the ``ext4`` subsystem, testing the ``inode`` area. +``kunit_try_catch`` + Part of the ``kunit`` implementation itself, testing the ``try_catch`` area. +``apparmor_property_entry`` + Part of the ``apparmor`` subsystem, testing the ``property_entry`` area. +``kasan`` + The ``kasan`` subsystem has only one suite, so the suite name is the same as + the subsystem name. + +Avoid names like: + +``ext4_ext4_inode`` + There's no reason to state the subsystem twice. +``property_entry`` + The suite name is ambiguous without the subsystem name. +``kasan_unit_test`` + Because there is only one suite in the ``kasan`` subsystem, the suite should + just be called ``kasan``. There's no need to redundantly add ``unit_test``. + +Test Cases +---------- + +Individual tests consist of a single function which tests a constrained +codepath, property, or function. In the test output, individual tests' results +will show up as subtests of the suite's results. + +Tests should be named after what they're testing. This is often the name of the +function being tested, with a description of the input or codepath being tested. +As tests are C functions, they should be named and written in accordance with +the kernel coding style. + +.. note:: + As tests are themselves functions, their names cannot conflict with + other C identifiers in the kernel. This may require some creative + naming. It's a good idea to make your test functions `static` to avoid + polluting the global namespace. + +Example test names include: + +``unpack_u32_with_null_name`` + Tests the ``unpack_u32`` function when a NULL name is passed in. +``test_list_splice`` + Tests the ``list_splice`` macro. It has the prefix ``test_`` to avoid a + name conflict with the macro itself. + + +Should it be necessary to refer to a test outside the context of its test suite, +the *fully-qualified* name of a test should be the suite name followed by the +test name, separated by a colon (i.e. ``suite:test``). + +Test Kconfig Entries +==================== + +Every test suite should be tied to a Kconfig entry. + +This Kconfig entry must: + +* be named ``CONFIG_<name>_KUNIT_TEST``: where <name> is the name of the test + suite. +* be listed either alongside the config entries for the driver/subsystem being + tested, or be under [Kernel Hacking]→[Kernel Testing and Coverage] +* depend on ``CONFIG_KUNIT`` +* be visible only if ``CONFIG_KUNIT_ALL_TESTS`` is not enabled. +* have a default value of ``CONFIG_KUNIT_ALL_TESTS``. +* have a brief description of KUnit in the help text + +Unless there's a specific reason not to (e.g. the test is unable to be built as +a module), Kconfig entries for tests should be tristate. + +An example Kconfig entry: + +.. code-block:: none + + config FOO_KUNIT_TEST + tristate "KUnit test for foo" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + This builds unit tests for foo. + + For more information on KUnit and unit tests in general, please refer + to the KUnit documentation in Documentation/dev-tools/kunit + + If unsure, say N + + +Test Filenames +============== + +Where possible, test suites should be placed in a separate source file in the +same directory as the code being tested. + +This file should be named ``<suite>_kunit.c``. It may make sense to strip +excessive namespacing from the source filename (e.g., ``firmware_kunit.c`` instead of +``<drivername>_firmware.c``), but please ensure the module name does contain the +full suite name. + + -- 2.27.0.212.ge8ba1cc988-goog

4 years, 3 months

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[PATCH v2 00/11] Introduce kernel_clone(), kill _do_fork()

by Christian Brauner

Hey everyone, This is a follow-up to the fork-related cleanup. It's based on a brief discussion after the initial series was merged. Last cycle we removed copy_thread_tls() and the associated Kconfig option for each architecture. Now we are only left with copy_thread(). Part of this work was removing the old do_fork() legacy clone()-style calling convention in favor of the new struct kernel_clone args calling convention. The only remaining function callable outside of kernel/fork.c is _do_fork(). It doesn't really follow the naming of kernel-internal syscall helpers as Christoph righly pointed out. Switch all callers and references to kernel_clone() and remove _do_fork() once and for all also switching the return value for kernel_clone() from long to pid_t since that's what we use in all other places where we're dealing with process identifiers. For all architectures I have done a full git rebase v5.9-rc1 -x "make -j31". There were no built failures and the changes were fairly mechanical. The only helpers we have left now are kernel_thread() and kernel_clone() where kernel_thread() just calls kernel_clone(). Thanks! Christian Christian Brauner (11): fork: introduce kernel_clone() h8300: switch to kernel_clone() ia64: switch to kernel_clone() m68k: switch to kernel_clone() nios2: switch to kernel_clone() sparc: switch to kernel_clone() x86: switch to kernel_clone() kprobes: switch to kernel_clone() kgdbts: switch to kernel_clone() tracing: switch to kernel_clone() sched: remove _do_fork() Documentation/trace/histogram.rst | 4 +- arch/h8300/kernel/process.c | 2 +- arch/ia64/kernel/process.c | 4 +- arch/m68k/kernel/process.c | 10 ++-- arch/nios2/kernel/process.c | 2 +- arch/sparc/kernel/process.c | 6 +-- arch/x86/kernel/sys_ia32.c | 2 +- drivers/misc/kgdbts.c | 48 +++++++++---------- include/linux/sched/task.h | 2 +- kernel/fork.c | 16 +++---- samples/kprobes/kprobe_example.c | 6 +-- samples/kprobes/kretprobe_example.c | 4 +- .../test.d/dynevent/add_remove_kprobe.tc | 2 +- .../test.d/dynevent/clear_select_events.tc | 2 +- .../test.d/dynevent/generic_clear_event.tc | 2 +- .../test.d/ftrace/func-filter-stacktrace.tc | 4 +- .../ftrace/test.d/kprobe/add_and_remove.tc | 2 +- .../ftrace/test.d/kprobe/busy_check.tc | 2 +- .../ftrace/test.d/kprobe/kprobe_args.tc | 4 +- .../ftrace/test.d/kprobe/kprobe_args_comm.tc | 2 +- .../test.d/kprobe/kprobe_args_string.tc | 4 +- .../test.d/kprobe/kprobe_args_symbol.tc | 10 ++-- .../ftrace/test.d/kprobe/kprobe_args_type.tc | 2 +- .../ftrace/test.d/kprobe/kprobe_ftrace.tc | 14 +++--- .../ftrace/test.d/kprobe/kprobe_multiprobe.tc | 2 +- .../test.d/kprobe/kprobe_syntax_errors.tc | 12 ++--- .../ftrace/test.d/kprobe/kretprobe_args.tc | 4 +- .../selftests/ftrace/test.d/kprobe/profile.tc | 2 +- 28 files changed, 88 insertions(+), 88 deletions(-) base-commit: 9123e3a74ec7b934a4a099e98af6a61c2f80bbf5 -- 2.28.0

4 years, 3 months

4
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[PATCH] selftests: rtnetlink: load fou module for kci_test_encap_fou()

by Po-Hsu Lin

The kci_test_encap_fou() test from kci_test_encap() in rtnetlink.sh needs the fou module to work. Otherwise it will fail with: $ ip netns exec "$testns" ip fou add port 7777 ipproto 47 RTNETLINK answers: No such file or directory Error talking to the kernel Add the CONFIG_NET_FOU into the config file as well. Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com> --- tools/testing/selftests/net/config | 1 + tools/testing/selftests/net/rtnetlink.sh | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/tools/testing/selftests/net/config b/tools/testing/selftests/net/config index 3b42c06b..96d2763 100644 --- a/tools/testing/selftests/net/config +++ b/tools/testing/selftests/net/config @@ -31,3 +31,4 @@ CONFIG_NET_SCH_ETF=m CONFIG_NET_SCH_NETEM=y CONFIG_TEST_BLACKHOLE_DEV=m CONFIG_KALLSYMS=y +CONFIG_NET_FOU diff --git a/tools/testing/selftests/net/rtnetlink.sh b/tools/testing/selftests/net/rtnetlink.sh index bdbf4b3..7931b65 100755 --- a/tools/testing/selftests/net/rtnetlink.sh +++ b/tools/testing/selftests/net/rtnetlink.sh @@ -521,6 +521,11 @@ kci_test_encap_fou() return $ksft_skip fi + if ! /sbin/modprobe -q -n fou; then + echo "SKIP: module fou is not found" + return $ksft_skip + fi + /sbin/modprobe -q fou ip -netns "$testns" fou add port 7777 ipproto 47 2>/dev/null if [ $? -ne 0 ];then echo "FAIL: can't add fou port 7777, skipping test" @@ -541,6 +546,7 @@ kci_test_encap_fou() return 1 fi + /sbin/modprobe -q -r fou echo "PASS: fou" } -- 2.7.4

4 years, 3 months

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[PATCH v2 0/4] Support non-blocking pidfds

by Christian Brauner

Hi, Passing a non-blocking pidfd to waitid() currently has no effect, i.e. is not supported. There are users which would like to use waitid() on pidfds that are O_NONBLOCK and mix it with pidfds that are blocking and both pass them to waitid(). The expected behavior is to have waitid() return -EAGAIN for non-blocking pidfds and to block for blocking pidfds without needing to perform any additional checks for flags set on the pidfd before passing it to waitid(). Non-blocking pidfds will return EAGAIN from waitid() when no child process is ready yet. Returning -EAGAIN for non-blocking pidfds makes it easier for event loops that handle EAGAIN specially. It also makes the API more consistent and uniform. In essence, waitid() is treated like a read on a non-blocking pidfd or a recvmsg() on a non-blocking socket. With the addition of support for non-blocking pidfds we support the same functionality that sockets do. For sockets() recvmsg() supports MSG_DONTWAIT for pidfds waitid() supports WNOHANG. Both flags are per-call options. In contrast non-blocking pidfds and non-blocking sockets are a setting on an open file description affecting all threads in the calling process as well as other processes that hold file descriptors referring to the same open file description. Both behaviors, per call and per open file description, have genuine use-cases. A concrete use-case that was brought on-list (see [1]) was Josh's async pidfd library. Ever since the introduction of pidfds and more advanced async io various programming languages such as Rust have grown support for async event libraries. These libraries are created to help build epoll-based event loops around file descriptors. A common pattern is to automatically make all file descriptors they manage to O_NONBLOCK. For such libraries the EAGAIN error code is treated specially. When a function is called that returns EAGAIN the function isn't called again until the event loop indicates the the file descriptor is ready. Supporting EAGAIN when waiting on pidfds makes such libraries just work with little effort. Thanks! Christian [1]: https://lore.kernel.org/lkml/20200811181236.GA18763@localhost/ Christian Brauner (4): pidfd: support PIDFD_NONBLOCK in pidfd_open() exit: support non-blocking pidfds tests: port pidfd_wait to kselftest harness tests: add waitid() tests for non-blocking pidfds include/uapi/linux/pidfd.h | 12 + kernel/exit.c | 15 +- kernel/pid.c | 12 +- tools/testing/selftests/pidfd/pidfd.h | 4 + tools/testing/selftests/pidfd/pidfd_wait.c | 298 +++++++++------------ 5 files changed, 157 insertions(+), 184 deletions(-) create mode 100644 include/uapi/linux/pidfd.h base-commit: d012a7190fc1fd72ed48911e77ca97ba4521bccd -- 2.28.0

4 years, 3 months

3
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[PATCH] selftests/bpf: Fix check in global_data_init.

by Hao Luo

The returned value of bpf_object__open_file() should be checked with libbpf_get_error() rather than NULL. This fix prevents test_progs from crash when test_global_data.o is not present. Signed-off-by: Hao Luo <haoluo(a)google.com> --- tools/testing/selftests/bpf/prog_tests/global_data_init.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/global_data_init.c b/tools/testing/selftests/bpf/prog_tests/global_data_init.c index 3bdaa5a40744..ee46b11f1f9a 100644 --- a/tools/testing/selftests/bpf/prog_tests/global_data_init.c +++ b/tools/testing/selftests/bpf/prog_tests/global_data_init.c @@ -12,7 +12,8 @@ void test_global_data_init(void) size_t sz; obj = bpf_object__open_file(file, NULL); - if (CHECK_FAIL(!obj)) + err = libbpf_get_error(obj); + if (CHECK_FAIL(err)) return; map = bpf_object__find_map_by_name(obj, "test_glo.rodata"); -- 2.28.0.526.ge36021eeef-goog

4 years, 3 months

3
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[PATCH] selftests/net: improve descriptions for XFAIL cases in psock_snd.sh

by Po-Hsu Lin

Before changing this it's a bit confusing to read test output: raw csum_off with bad offset (fails) ./psock_snd: write: Invalid argument Change "fails" in the test case description to "expected to fail", so that the test output can be more understandable. Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com> --- tools/testing/selftests/net/psock_snd.sh | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/net/psock_snd.sh b/tools/testing/selftests/net/psock_snd.sh index 6331d91..170be65 100755 --- a/tools/testing/selftests/net/psock_snd.sh +++ b/tools/testing/selftests/net/psock_snd.sh @@ -45,7 +45,7 @@ echo "raw vnet hdr" echo "raw csum_off" ./in_netns.sh ./psock_snd -v -c -echo "raw csum_off with bad offset (fails)" +echo "raw csum_off with bad offset (expected to fail)" (! ./in_netns.sh ./psock_snd -v -c -C) @@ -57,7 +57,7 @@ echo "raw min size" echo "raw mtu size" ./in_netns.sh ./psock_snd -l "${mss}" -echo "raw mtu size + 1 (fails)" +echo "raw mtu size + 1 (expected to fail)" (! ./in_netns.sh ./psock_snd -l "${mss_exceeds}") # fails due to ARPHRD_ETHER check in packet_extra_vlan_len_allowed @@ -65,19 +65,19 @@ echo "raw mtu size + 1 (fails)" # echo "raw vlan mtu size" # ./in_netns.sh ./psock_snd -V -l "${mss}" -echo "raw vlan mtu size + 1 (fails)" +echo "raw vlan mtu size + 1 (expected to fail)" (! ./in_netns.sh ./psock_snd -V -l "${mss_exceeds}") echo "dgram mtu size" ./in_netns.sh ./psock_snd -d -l "${mss}" -echo "dgram mtu size + 1 (fails)" +echo "dgram mtu size + 1 (expected to fail)" (! ./in_netns.sh ./psock_snd -d -l "${mss_exceeds}") -echo "raw truncate hlen (fails: does not arrive)" +echo "raw truncate hlen (expected to fail: does not arrive)" (! ./in_netns.sh ./psock_snd -t "$((${vnet_hlen} + ${eth_hlen}))") -echo "raw truncate hlen - 1 (fails: EINVAL)" +echo "raw truncate hlen - 1 (expected to fail: EINVAL)" (! ./in_netns.sh ./psock_snd -t "$((${vnet_hlen} + ${eth_hlen} - 1))") @@ -86,13 +86,13 @@ echo "raw truncate hlen - 1 (fails: EINVAL)" echo "raw gso min size" ./in_netns.sh ./psock_snd -v -c -g -l "${mss_exceeds}" -echo "raw gso min size - 1 (fails)" +echo "raw gso min size - 1 (expected to fail)" (! ./in_netns.sh ./psock_snd -v -c -g -l "${mss}") echo "raw gso max size" ./in_netns.sh ./psock_snd -v -c -g -l "${max_mss}" -echo "raw gso max size + 1 (fails)" +echo "raw gso max size + 1 (expected to fail)" (! ./in_netns.sh ./psock_snd -v -c -g -l "${max_mss_exceeds}") echo "OK. All tests passed" -- 2.7.4

4 years, 3 months

2
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[PATCH] selftests/bpf: Fix check in global_data_init.

by Hao Luo

The returned value of bpf_object__open_file() should be checked with IS_ERR() rather than NULL. This fix makes test_progs not crash when test_global_data.o is not present. Signed-off-by: Hao Luo <haoluo(a)google.com> --- tools/testing/selftests/bpf/prog_tests/global_data_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/global_data_init.c b/tools/testing/selftests/bpf/prog_tests/global_data_init.c index 3bdaa5a40744..1ece86d5c519 100644 --- a/tools/testing/selftests/bpf/prog_tests/global_data_init.c +++ b/tools/testing/selftests/bpf/prog_tests/global_data_init.c @@ -12,7 +12,7 @@ void test_global_data_init(void) size_t sz; obj = bpf_object__open_file(file, NULL); - if (CHECK_FAIL(!obj)) + if (CHECK_FAIL(IS_ERR(obj))) return; map = bpf_object__find_map_by_name(obj, "test_glo.rodata"); -- 2.28.0.402.g5ffc5be6b7-goog

4 years, 3 months

2
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[PATCH v3] mm/thp: fix __split_huge_pmd_locked() for migration PMD

by Ralph Campbell

A migrating transparent huge page has to already be unmapped. Otherwise, the page could be modified while it is being copied to a new page and data could be lost. The function __split_huge_pmd() checks for a PMD migration entry before calling __split_huge_pmd_locked() leading one to think that __split_huge_pmd_locked() can handle splitting a migrating PMD. However, the code always increments the page->_mapcount and adjusts the memory control group accounting assuming the page is mapped. Also, if the PMD entry is a migration PMD entry, the call to is_huge_zero_pmd(*pmd) is incorrect because it calls pmd_pfn(pmd) instead of migration_entry_to_pfn(pmd_to_swp_entry(pmd)). Fix these problems by checking for a PMD migration entry. Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path") cc: stable(a)vger.kernel.org # 4.14+ Signed-off-by: Ralph Campbell <rcampbell(a)nvidia.com> Reviewed-by: Yang Shi <shy828301(a)gmail.com> Reviewed-by: Zi Yan <ziy(a)nvidia.com> --- No changes in v3 to this patch, just added reviewed-by and fixes to the change log and sending this as a separate patch from the rest of the series ("mm/hmm/nouveau: add THP migration to migrate_vma_*"). I'll hold off resending the series without this patch unless there are changes needed. mm/huge_memory.c | 42 +++++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 19 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 2a468a4acb0a..606d712d9505 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2023,7 +2023,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, put_page(page); add_mm_counter(mm, mm_counter_file(page), -HPAGE_PMD_NR); return; - } else if (is_huge_zero_pmd(*pmd)) { + } else if (pmd_trans_huge(*pmd) && is_huge_zero_pmd(*pmd)) { /* * FIXME: Do we want to invalidate secondary mmu by calling * mmu_notifier_invalidate_range() see comments below inside @@ -2117,30 +2117,34 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, pte = pte_offset_map(&_pmd, addr); BUG_ON(!pte_none(*pte)); set_pte_at(mm, addr, pte, entry); - atomic_inc(&page[i]._mapcount); - pte_unmap(pte); - } - - /* - * Set PG_double_map before dropping compound_mapcount to avoid - * false-negative page_mapped(). - */ - if (compound_mapcount(page) > 1 && !TestSetPageDoubleMap(page)) { - for (i = 0; i < HPAGE_PMD_NR; i++) + if (!pmd_migration) atomic_inc(&page[i]._mapcount); + pte_unmap(pte); } - lock_page_memcg(page); - if (atomic_add_negative(-1, compound_mapcount_ptr(page))) { - /* Last compound_mapcount is gone. */ - __dec_lruvec_page_state(page, NR_ANON_THPS); - if (TestClearPageDoubleMap(page)) { - /* No need in mapcount reference anymore */ + if (!pmd_migration) { + /* + * Set PG_double_map before dropping compound_mapcount to avoid + * false-negative page_mapped(). + */ + if (compound_mapcount(page) > 1 && + !TestSetPageDoubleMap(page)) { for (i = 0; i < HPAGE_PMD_NR; i++) - atomic_dec(&page[i]._mapcount); + atomic_inc(&page[i]._mapcount); + } + + lock_page_memcg(page); + if (atomic_add_negative(-1, compound_mapcount_ptr(page))) { + /* Last compound_mapcount is gone. */ + __dec_lruvec_page_state(page, NR_ANON_THPS); + if (TestClearPageDoubleMap(page)) { + /* No need in mapcount reference anymore */ + for (i = 0; i < HPAGE_PMD_NR; i++) + atomic_dec(&page[i]._mapcount); + } } + unlock_page_memcg(page); } - unlock_page_memcg(page); smp_wmb(); /* make pte visible before pmd */ pmd_populate(mm, pmd, pgtable); -- 2.20.1

4 years, 3 months

1
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[PATCH v2 0/7] mm/hmm/nouveau: add THP migration to migrate_vma_*

by Ralph Campbell

This series adds support for transparent huge page migration to migrate_vma_*() and adds nouveau SVM and HMM selftests as consumers. An earlier version was posted previously [1]. This version now supports splitting a THP midway in the migration process which led to a number of changes. The patches apply cleanly to the current linux-mm tree. Since there are a couple of patches in linux-mm from Dan Williams that modify lib/test_hmm.c and drivers/gpu/drm/nouveau/nouveau_dmem.c, it might be easiest if Andrew could take these through the linux-mm tree assuming that's OK with other maintainers like Ben Skeggs. [1] https://lore.kernel.org/linux-mm/20200619215649.32297-1-rcampbell@nvidia.com Ralph Campbell (7): mm/thp: fix __split_huge_pmd_locked() for migration PMD mm/migrate: move migrate_vma_collect_skip() mm: support THP migration to device private memory mm/thp: add prep_transhuge_device_private_page() mm/thp: add THP allocation helper mm/hmm/test: add self tests for THP migration nouveau: support THP migration to private memory drivers/gpu/drm/nouveau/nouveau_dmem.c | 289 +++++++++++----- drivers/gpu/drm/nouveau/nouveau_svm.c | 11 +- drivers/gpu/drm/nouveau/nouveau_svm.h | 3 +- include/linux/gfp.h | 10 + include/linux/huge_mm.h | 12 + include/linux/memremap.h | 9 + include/linux/migrate.h | 2 + lib/test_hmm.c | 439 +++++++++++++++++++++---- lib/test_hmm_uapi.h | 3 + mm/huge_memory.c | 177 +++++++--- mm/memory.c | 10 +- mm/migrate.c | 429 +++++++++++++++++++----- mm/rmap.c | 2 +- tools/testing/selftests/vm/hmm-tests.c | 404 +++++++++++++++++++++++ 14 files changed, 1519 insertions(+), 281 deletions(-) -- 2.20.1

4 years, 3 months

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[PATCH 0/7] powerpc/watchpoint: 2nd DAWR kvm enablement + selftests

by Ravi Bangoria

Patch #1, #2 and #3 enables p10 2nd DAWR feature for Book3S kvm guest. DAWR is a hypervisor resource and thus H_SET_MODE hcall is used to set/unset it. A new case H_SET_MODE_RESOURCE_SET_DAWR1 is introduced in H_SET_MODE hcall for setting/unsetting 2nd DAWR. Also, new capability KVM_CAP_PPC_DAWR1 has been added to query 2nd DAWR support via kvm ioctl. This feature also needs to be enabled in Qemu to really use it. I'll reply link to qemu patches once I post them in qemu-devel mailing list. Patch #4, #5, #6 and #7 adds selftests to test 2nd DAWR. Dependency: 1: p10 kvm base enablement https://lore.kernel.org/linuxppc-dev/20200602055325.6102-1-alistair@popple.… 2: 2nd DAWR powervm/baremetal enablement https://lore.kernel.org/linuxppc-dev/20200723090813.303838-1-ravi.bangoria@… 3: ptrace PPC_DEBUG_FEATURE_DATA_BP_DAWR_ARCH_31 flag https://lore.kernel.org/linuxppc-dev/20200723093330.306341-1-ravi.bangoria@… Patches in this series applies fine on top of powerpc/next (9a77c4a0a125) plus above dependency patches. Ravi Bangoria (7): powerpc/watchpoint/kvm: Rename current DAWR macros and variables powerpc/watchpoint/kvm: Add infrastructure to support 2nd DAWR powerpc/watchpoint/kvm: Introduce new capability for 2nd DAWR powerpc/selftests/ptrace-hwbreak: Add testcases for 2nd DAWR powerpc/selftests/perf-hwbreak: Coalesce event creation code powerpc/selftests/perf-hwbreak: Add testcases for 2nd DAWR powerpc/selftests: Add selftest to test concurrent perf/ptrace events Documentation/virt/kvm/api.rst | 6 +- arch/powerpc/include/asm/hvcall.h | 2 + arch/powerpc/include/asm/kvm_host.h | 6 +- arch/powerpc/include/uapi/asm/kvm.h | 8 +- arch/powerpc/kernel/asm-offsets.c | 6 +- arch/powerpc/kvm/book3s_hv.c | 73 +- arch/powerpc/kvm/book3s_hv_nested.c | 15 +- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 43 +- arch/powerpc/kvm/powerpc.c | 3 + include/uapi/linux/kvm.h | 1 + tools/arch/powerpc/include/uapi/asm/kvm.h | 8 +- .../selftests/powerpc/ptrace/.gitignore | 1 + .../testing/selftests/powerpc/ptrace/Makefile | 2 +- .../selftests/powerpc/ptrace/perf-hwbreak.c | 646 +++++++++++++++-- .../selftests/powerpc/ptrace/ptrace-hwbreak.c | 79 +++ .../powerpc/ptrace/ptrace-perf-hwbreak.c | 659 ++++++++++++++++++ 16 files changed, 1476 insertions(+), 82 deletions(-) create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-perf-hwbreak.c -- 2.26.2

4 years, 3 months

2
15
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Linux-kselftest-mirror September 2020