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14185 discussions

[PATCH v3 0/9] selftests: vDSO: Some cleanups and (warning) fixes

by Thomas Weißschuh

Fixes and cleanups for various issues in the vDSO selftests. Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Changes in v3: - Rebase on v6.16-rc1 - Preserve vgetrandom_put_state() - Pick up vdso_standalone_test_x86 into this series - Link to v2: https://lore.kernel.org/r/20250505-selftests-vdso-fixes-v2-0-3bc86e42f242@l… Changes in v2: - Refer to -Wstrict-prototypes over -Wold-style-prototypes - Pick up Acks - Enable fixed warnings in Makefile - Link to v1: https://lore.kernel.org/r/20250502-selftests-vdso-fixes-v1-0-fb5d640a4f78@l… --- Thomas Weißschuh (9): selftests: vDSO: chacha: Correctly skip test if necessary selftests: vDSO: clock_getres: Drop unused include of err.h selftests: vDSO: vdso_test_getrandom: Drop unused include of linux/compiler.h selftests: vDSO: vdso_test_getrandom: Avoid -Wunused selftests: vDSO: vdso_config: Avoid -Wunused-variables selftests: vDSO: enable -Wall selftests: vDSO: vdso_test_correctness: Fix -Wstrict-prototypes selftests: vDSO: vdso_test_getrandom: Always print TAP header selftests: vDSO: vdso_standalone_test_x86: Replace source file with symlink tools/testing/selftests/vDSO/Makefile | 2 +- tools/testing/selftests/vDSO/vdso_config.h | 2 + .../selftests/vDSO/vdso_standalone_test_x86.c | 59 +--------------------- tools/testing/selftests/vDSO/vdso_test_chacha.c | 3 +- .../selftests/vDSO/vdso_test_clock_getres.c | 1 - .../testing/selftests/vDSO/vdso_test_correctness.c | 2 +- tools/testing/selftests/vDSO/vdso_test_getrandom.c | 10 ++-- 7 files changed, 13 insertions(+), 66 deletions(-) --- base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494 change-id: 20250423-selftests-vdso-fixes-d2ce74142359 Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

6 months, 3 weeks

nolibc test target overwites kernel config without asking

by Mark Brown

Hi, While running the nolibc tests I discovered that they build a kernel in the current directory, including overwriting the existing .config. This is rather suprising for the selftests build system - it usually wouldn't do a kernel build at all - and might be annoying for users. KUnit deals with this by doing it's kernel build in a .kunit directory, it'd probably be good to do something similar for nolibc. Thanks, Mark

6 months, 3 weeks

[PATCH v2] selftests/mm: Use generic read_sysfs in thuge-gen test

by Pu Lehui

From: Pu Lehui <pulehui(a)huawei.com> As generic read_sysfs is available in vm_utils, let's use is in thuge-gen test. Signed-off-by: Pu Lehui <pulehui(a)huawei.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> --- v2: - Explicit warning when ps != getpagesize(). (Lorenzo) tools/testing/selftests/mm/thuge-gen.c | 38 +++++++------------------- 1 file changed, 10 insertions(+), 28 deletions(-) diff --git a/tools/testing/selftests/mm/thuge-gen.c b/tools/testing/selftests/mm/thuge-gen.c index 95b6f043a3cb..8e2b08dc5762 100644 --- a/tools/testing/selftests/mm/thuge-gen.c +++ b/tools/testing/selftests/mm/thuge-gen.c @@ -77,40 +77,20 @@ void show(unsigned long ps) system(buf); } -unsigned long thuge_read_sysfs(int warn, char *fmt, ...) +unsigned long read_free(unsigned long ps) { - char *line = NULL; - size_t linelen = 0; - char buf[100]; - FILE *f; - va_list ap; unsigned long val = 0; + char buf[100]; - va_start(ap, fmt); - vsnprintf(buf, sizeof buf, fmt, ap); - va_end(ap); + snprintf(buf, sizeof(buf), + "/sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages", + ps >> 10); + if (read_sysfs(buf, &val) && ps != getpagesize()) + ksft_print_msg("missing %s\n", buf); - f = fopen(buf, "r"); - if (!f) { - if (warn) - ksft_print_msg("missing %s\n", buf); - return 0; - } - if (getline(&line, &linelen, f) > 0) { - sscanf(line, "%lu", &val); - } - fclose(f); - free(line); return val; } -unsigned long read_free(unsigned long ps) -{ - return thuge_read_sysfs(ps != getpagesize(), - "/sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages", - ps >> 10); -} - void test_mmap(unsigned long size, unsigned flags) { char *map; @@ -173,6 +153,7 @@ void test_shmget(unsigned long size, unsigned flags) void find_pagesizes(void) { unsigned long largest = getpagesize(); + unsigned long shmmax_val = 0; int i; glob_t g; @@ -195,7 +176,8 @@ void find_pagesizes(void) } globfree(&g); - if (thuge_read_sysfs(0, "/proc/sys/kernel/shmmax") < NUM_PAGES * largest) + read_sysfs("/proc/sys/kernel/shmmax", &shmmax_val); + if (shmmax_val < NUM_PAGES * largest) ksft_exit_fail_msg("Please do echo %lu > /proc/sys/kernel/shmmax", largest * NUM_PAGES); -- 2.34.1

6 months, 3 weeks

[PATCH] selftests/mm: Use generic read_sysfs in thuge-gen test

by Pu Lehui

From: Pu Lehui <pulehui(a)huawei.com> As generic read_sysfs is available in vm_utils, let's use is in thuge-gen test. Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- tools/testing/selftests/mm/thuge-gen.c | 37 +++++++------------------- 1 file changed, 9 insertions(+), 28 deletions(-) diff --git a/tools/testing/selftests/mm/thuge-gen.c b/tools/testing/selftests/mm/thuge-gen.c index 95b6f043a3cb..e11dfbfa661b 100644 --- a/tools/testing/selftests/mm/thuge-gen.c +++ b/tools/testing/selftests/mm/thuge-gen.c @@ -77,40 +77,19 @@ void show(unsigned long ps) system(buf); } -unsigned long thuge_read_sysfs(int warn, char *fmt, ...) +unsigned long read_free(unsigned long ps) { - char *line = NULL; - size_t linelen = 0; - char buf[100]; - FILE *f; - va_list ap; unsigned long val = 0; + char buf[100]; - va_start(ap, fmt); - vsnprintf(buf, sizeof buf, fmt, ap); - va_end(ap); + snprintf(buf, sizeof(buf), + "/sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages", + ps >> 10); + read_sysfs(buf, &val); - f = fopen(buf, "r"); - if (!f) { - if (warn) - ksft_print_msg("missing %s\n", buf); - return 0; - } - if (getline(&line, &linelen, f) > 0) { - sscanf(line, "%lu", &val); - } - fclose(f); - free(line); return val; } -unsigned long read_free(unsigned long ps) -{ - return thuge_read_sysfs(ps != getpagesize(), - "/sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages", - ps >> 10); -} - void test_mmap(unsigned long size, unsigned flags) { char *map; @@ -173,6 +152,7 @@ void test_shmget(unsigned long size, unsigned flags) void find_pagesizes(void) { unsigned long largest = getpagesize(); + unsigned long shmmax_val = 0; int i; glob_t g; @@ -195,7 +175,8 @@ void find_pagesizes(void) } globfree(&g); - if (thuge_read_sysfs(0, "/proc/sys/kernel/shmmax") < NUM_PAGES * largest) + read_sysfs("/proc/sys/kernel/shmmax", &shmmax_val); + if (shmmax_val < NUM_PAGES * largest) ksft_exit_fail_msg("Please do echo %lu > /proc/sys/kernel/shmmax", largest * NUM_PAGES); -- 2.34.1

6 months, 3 weeks

[PATCH] Documentation: kunit: fix argument of MODULE_IMPORT_NS()

by Thomas Weißschuh

The argument to MODULE_IMPORT_NS() should be a string literal. See commit cdd30ebb1b9f ("module: Convert symbol namespace to string literal") Fixes: d208025db6d6 ("Documentation: kunit: improve example on testing static functions") Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Documentation/dev-tools/kunit/usage.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst index 038f480074fd7aaa1f8e1b344bc74bf3426cc173..066ecda1dd98e73a01d50545e79c38a99a3e05a2 100644 --- a/Documentation/dev-tools/kunit/usage.rst +++ b/Documentation/dev-tools/kunit/usage.rst @@ -699,7 +699,7 @@ the template below. #include <kunit/visibility.h> #include <my_file.h> ... - MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING); + MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING"); ... // Use do_interesting_thing() in tests --- base-commit: f09079bd04a924c72d555cd97942d5f8d7eca98c change-id: 20250611-kunit-example-d195e41c0b34 Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

6 months, 3 weeks

[PATCH net-next 0/7] netpoll: Untangle netconsole and netpoll

by Breno Leitao

Initially netpoll and netconsole were created together, and some functions are in the wrong file. Seperate netconsole-only functions in netconsole, avoiding exports. 1. Expose netpoll logging macros in the public header to enable consistent log formatting across netpoll consumers. 2. Relocate netconsole-specific functions from netpoll to the netconsole module where they are actually used, reducing unnecessary coupling. 3. Remove unnecessary function exports 4. Rename netpoll parsing functions in netconsole to better reflect their specific usage. 5. Create a test to check that cmdline works fine. This was in my todo list since [1], this was a good time to add it here to make sure this patchset doesn't regress. PS: The code was split in a way that it is easy to review. When copying the functions from netpoll to netconsole, I do not change than other than adding `static`. This will make checkpatch unhappy, but, further patches will address the issues. It is done this way to make it easy for reviewers. Link: https://lore.kernel.org/netdev/Z36TlACdNMwFD7wv@dev-ushankar.dev.purestorag… [1] Signed-off-by: Breno Leitao <leitao(a)debian.org> --- Breno Leitao (7): netpoll: remove __netpoll_cleanup from exported API netpoll: expose netpoll logging macros in public header netpoll: relocate netconsole-specific functions to netconsole module netpoll: move netpoll_print_options to netconsole netconsole: rename functions to better reflect their purpose netconsole: improve code style in parser function selftest: netconsole: add test for cmdline configuration drivers/net/netconsole.c | 137 ++++++++++++++++++++- include/linux/netpoll.h | 10 +- net/core/netpoll.c | 136 +------------------- tools/testing/selftests/drivers/net/Makefile | 1 + .../selftests/drivers/net/lib/sh/lib_netcons.sh | 39 +++++- .../selftests/drivers/net/netcons_cmdline.sh | 52 ++++++++ 6 files changed, 228 insertions(+), 147 deletions(-) --- base-commit: 2c7e4a2663a1ab5a740c59c31991579b6b865a26 change-id: 20250603-rework-c175cad8d22e Best regards, -- Breno Leitao <leitao(a)debian.org>

6 months, 3 weeks

[PATCH net-next] selftests/net: packetdrill: more xfail changes

by Jakub Kicinski

Most of the packetdrill tests have not flaked once last week. Add the few which did to the XFAIL list. Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> --- CC: shuah(a)kernel.org CC: willemb(a)google.com CC: matttbe(a)kernel.org CC: linux-kselftest(a)vger.kernel.org Every time I sit down to add more I plan to just XFAIL all of packetdrill on slow machines, but then I convince myself otherwise. One last time? --- tools/testing/selftests/net/packetdrill/ksft_runner.sh | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/testing/selftests/net/packetdrill/ksft_runner.sh b/tools/testing/selftests/net/packetdrill/ksft_runner.sh index ef8b25a606d8..c5b01e1bd4c7 100755 --- a/tools/testing/selftests/net/packetdrill/ksft_runner.sh +++ b/tools/testing/selftests/net/packetdrill/ksft_runner.sh @@ -39,11 +39,15 @@ if [[ -n "${KSFT_MACHINE_SLOW}" ]]; then # xfail tests that are known flaky with dbg config, not fixable. # still run them for coverage (and expect 100% pass without dbg). declare -ar xfail_list=( + "tcp_blocking_blocking-connect.pkt" + "tcp_blocking_blocking-read.pkt" "tcp_eor_no-coalesce-retrans.pkt" "tcp_fast_recovery_prr-ss.*.pkt" + "tcp_sack_sack-route-refresh-ip-tos.pkt" "tcp_slow_start_slow-start-after-win-update.pkt" "tcp_timestamping.*.pkt" "tcp_user_timeout_user-timeout-probe.pkt" + "tcp_zerocopy_cl.*.pkt" "tcp_zerocopy_epoll_.*.pkt" "tcp_tcp_info_tcp-info-.*-limited.pkt" ) -- 2.49.0

6 months, 3 weeks

[PATCH] selftests: Add version file to kselftest installation dir

by Tianyi Cui

As titled, adding version file to kselftest installation dir, so the user of the tarball can know which kernel version the tarball belongs to. Signed-off-by: Tianyi Cui <1997cui(a)gmail.com> --- tools/testing/selftests/Makefile | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index a0a6ba47d600..246e9863b45b 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -291,6 +291,12 @@ ifdef INSTALL_PATH $(MAKE) -s --no-print-directory OUTPUT=$$BUILD_TARGET COLLECTION=$$TARGET \ -C $$TARGET emit_tests >> $(TEST_LIST); \ done; + @if git describe HEAD > /dev/null 2>&1; then \ + git describe HEAD > $(INSTALL_PATH)/VERSION; \ + printf "Version saved to $(INSTALL_PATH)/VERSION\n"; \ + else \ + printf "Unable to get version from git describe\n"; \ + fi else $(error Error: set INSTALL_PATH to use install) endif -- 2.47.1

6 months, 3 weeks

[PATCH net-next v3 0/4] netconsole: Optimize console registration and improve testing

by Breno Leitao

During performance analysis of console subsystem latency, I discovered that netconsole registers console handlers even when no active targets exist. These orphaned console handlers are invoked on every printk() call, get the lock, iterate through empty target lists, and consume CPU cycles without performing any useful work. This patch series addresses the inefficiency by: 1. Implementing dynamic console registration/unregistration based on target availability, ensuring console handlers are only active when needed 2. Adding automatic cleanup of unused console registrations when targets are disabled or removed 3. Extending the selftest suite to cover non-extended console format, which was previously untested The optimization reduces printk() overhead by eliminating unnecessary function calls and list traversals when netconsole targets are not configured, improving overall system performance during heavy logging scenarios. --- Changes in v3: - Set CON_ENABLED before re-enabling the console, to fix a selftest that was failing, as reported by Jakub on v2. - Link to v2: https://lore.kernel.org/r/20250602-netcons_ext-v2-0-ef88d999326d@debian.org Changes in v2: - Added selftests to test the new mechanism - Unregister the console if the last target got disabled - Sending to net-next instead of net (Jakub) - Link to v1: https://lore.kernel.org/r/20250528-netcons_ext-v1-1-69f71e404e00@debian.org --- Breno Leitao (4): netconsole: Only register console drivers when targets are configured netconsole: Add automatic console unregistration on target removal selftests: netconsole: Do not exit from inside the validation function selftests: netconsole: Add support for basic netconsole target format drivers/net/netconsole.c | 67 +++++++++++++++++++--- .../selftests/drivers/net/lib/sh/lib_netcons.sh | 27 +++++++-- .../testing/selftests/drivers/net/netcons_basic.sh | 50 ++++++++++------ 3 files changed, 112 insertions(+), 32 deletions(-) --- base-commit: 2c7e4a2663a1ab5a740c59c31991579b6b865a26 change-id: 20250528-netcons_ext-572982619bea Best regards, -- Breno Leitao <leitao(a)debian.org>

6 months, 3 weeks

[PATCH RFC net-next v2] page_pool: import Jesper's page_pool benchmark

by Mina Almasry

From: Jesper Dangaard Brouer <hawk(a)kernel.org> We frequently consult with Jesper's out-of-tree page_pool benchmark to evaluate page_pool changes. Import the benchmark into the upstream linux kernel tree so that (a) we're all running the same version, (b) pave the way for shared improvements, and (c) maybe one day integrate it with nipa, if possible. Import bench_page_pool_simple from commit 35b1716d0c30 ("Add page_bench06_walk_all"), from this repository: https://github.com/netoptimizer/prototype-kernel.git Changes done during upstreaming: - Fix checkpatch issues. - Remove the tasklet logic not needed. - Move under tools/testing - Create ksft for the benchmark. - Changed slightly how the benchmark gets build. Out of tree, time_bench is built as an independent .ko. Here it is included in bench_page_pool.ko Steps to run: ``` mkdir -p /tmp/run-pp-bench make -C ./tools/testing/selftests/net/bench make -C ./tools/testing/selftests/net/bench install INSTALL_PATH=/tmp/run-pp-bench rsync --delete -avz --progress /tmp/run-pp-bench mina@$SERVER:~/ ssh mina@$SERVER << EOF cd ~/run-pp-bench && sudo ./test_bench_page_pool.sh EOF ``` Output: ``` (benchmrk dmesg logs) Fast path results: no-softirq-page_pool01 Per elem: 11 cycles(tsc) 4.368 ns ptr_ring results: no-softirq-page_pool02 Per elem: 527 cycles(tsc) 195.187 ns slow path results: no-softirq-page_pool03 Per elem: 549 cycles(tsc) 203.466 ns ``` Cc: Jesper Dangaard Brouer <hawk(a)kernel.org> Cc: Ilias Apalodimas <ilias.apalodimas(a)linaro.org> Cc: Jakub Kicinski <kuba(a)kernel.org> Cc: Toke Høiland-Jørgensen <toke(a)toke.dk> Signed-off-by: Mina Almasry <almasrymina(a)google.com> --- v2: - Move under tools/selftests (Jakub) - Create ksft for it. - Remove the tasklet logic no longer needed (Jesper + Toke) RFC discussion points: - Desirable to import it? - Can the benchmark be imported as-is for an initial version? Or needs lots of modifications? - Code location. I retained the location in Jesper's tree, but a path like net/core/bench/ may make more sense. --- tools/testing/selftests/net/bench/Makefile | 7 + .../selftests/net/bench/page_pool/Makefile | 17 + .../bench/page_pool/bench_page_pool_simple.c | 275 ++++++++++++ .../bench/page_pool/test_bench_page_pool.sh | 32 ++ .../net/bench/page_pool/time_bench.c | 406 ++++++++++++++++++ .../net/bench/page_pool/time_bench.h | 259 +++++++++++ 6 files changed, 996 insertions(+) create mode 100644 tools/testing/selftests/net/bench/Makefile create mode 100644 tools/testing/selftests/net/bench/page_pool/Makefile create mode 100644 tools/testing/selftests/net/bench/page_pool/bench_page_pool_simple.c create mode 100755 tools/testing/selftests/net/bench/page_pool/test_bench_page_pool.sh create mode 100644 tools/testing/selftests/net/bench/page_pool/time_bench.c create mode 100644 tools/testing/selftests/net/bench/page_pool/time_bench.h diff --git a/tools/testing/selftests/net/bench/Makefile b/tools/testing/selftests/net/bench/Makefile new file mode 100644 index 000000000000..4ebce5d71b18 --- /dev/null +++ b/tools/testing/selftests/net/bench/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0 + +TEST_GEN_MODS_DIR := page_pool + +TEST_PROGS += page_pool/test_bench_page_pool.sh + +include ../../lib.mk diff --git a/tools/testing/selftests/net/bench/page_pool/Makefile b/tools/testing/selftests/net/bench/page_pool/Makefile new file mode 100644 index 000000000000..0549a16ba275 --- /dev/null +++ b/tools/testing/selftests/net/bench/page_pool/Makefile @@ -0,0 +1,17 @@ +BENCH_PAGE_POOL_SIMPLE_TEST_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST))))) +KDIR ?= /lib/modules/$(shell uname -r)/build + +ifeq ($(V),1) +Q = +else +Q = @ +endif + +obj-m += bench_page_pool.o +bench_page_pool-y += bench_page_pool_simple.o time_bench.o + +all: + +$(Q)make -C $(KDIR) M=$(BENCH_PAGE_POOL_SIMPLE_TEST_DIR) modules + +clean: + +$(Q)make -C $(KDIR) M=$(BENCH_PAGE_POOL_SIMPLE_TEST_DIR) clean diff --git a/tools/testing/selftests/net/bench/page_pool/bench_page_pool_simple.c b/tools/testing/selftests/net/bench/page_pool/bench_page_pool_simple.c new file mode 100644 index 000000000000..53d168cce27d --- /dev/null +++ b/tools/testing/selftests/net/bench/page_pool/bench_page_pool_simple.c @@ -0,0 +1,275 @@ +/* + * Benchmark module for page_pool. + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/mutex.h> + +#include <linux/version.h> +#include <net/page_pool/helpers.h> + +#include <linux/interrupt.h> +#include <linux/limits.h> + +#include "time_bench.h" + +static int verbose = 1; +#define MY_POOL_SIZE 1024 + +static inline void _page_pool_put_page(struct page_pool *pool, + struct page *page, bool allow_direct) +{ + page_pool_put_page(pool, page, -1, allow_direct); +} + +/* Makes tests selectable. Useful for perf-record to analyze a single test. + * Hint: Bash shells support writing binary number like: $((2#101010) + * + * # modprobe bench_page_pool_simple run_flags=$((2#100)) + */ +static unsigned long run_flags = 0xFFFFFFFF; +module_param(run_flags, ulong, 0); +MODULE_PARM_DESC(run_flags, "Limit which bench test that runs"); +/* Count the bit number from the enum */ +enum benchmark_bit { + bit_run_bench_baseline, + bit_run_bench_no_softirq01, + bit_run_bench_no_softirq02, + bit_run_bench_no_softirq03, +}; +#define bit(b) (1 << (b)) +#define enabled(b) ((run_flags & (bit(b)))) + +/* notice time_bench is limited to U32_MAX nr loops */ +static unsigned long loops = 10000000; +module_param(loops, ulong, 0); +MODULE_PARM_DESC(loops, "Specify loops bench will run"); + +/* Timing at the nanosec level, we need to know the overhead + * introduced by the for loop itself */ +static int time_bench_for_loop(struct time_bench_record *rec, void *data) +{ + uint64_t loops_cnt = 0; + int i; + + time_bench_start(rec); + /** Loop to measure **/ + for (i = 0; i < rec->loops; i++) { + loops_cnt++; + barrier(); /* avoid compiler to optimize this loop */ + } + time_bench_stop(rec, loops_cnt); + return loops_cnt; +} + +static int time_bench_atomic_inc(struct time_bench_record *rec, void *data) +{ + uint64_t loops_cnt = 0; + atomic_t cnt; + int i; + + atomic_set(&cnt, 0); + + time_bench_start(rec); + /** Loop to measure **/ + for (i = 0; i < rec->loops; i++) { + atomic_inc(&cnt); + barrier(); /* avoid compiler to optimize this loop */ + } + loops_cnt = atomic_read(&cnt); + time_bench_stop(rec, loops_cnt); + return loops_cnt; +} + +/* The ptr_ping in page_pool uses a spinlock. We need to know the minimum + * overhead of taking+releasing a spinlock, to know the cycles that can be saved + * by e.g. amortizing this via bulking. + */ +static int time_bench_lock(struct time_bench_record *rec, void *data) +{ + uint64_t loops_cnt = 0; + spinlock_t lock; + int i; + + spin_lock_init(&lock); + + time_bench_start(rec); + /** Loop to measure **/ + for (i = 0; i < rec->loops; i++) { + spin_lock(&lock); + loops_cnt++; + barrier(); /* avoid compiler to optimize this loop */ + spin_unlock(&lock); + } + time_bench_stop(rec, loops_cnt); + return loops_cnt; +} + +/* Helper for filling some page's into ptr_ring */ +static void pp_fill_ptr_ring(struct page_pool *pp, int elems) +{ + gfp_t gfp_mask = GFP_ATOMIC; /* GFP_ATOMIC needed when under run softirq */ + struct page **array; + int i; + + array = kzalloc(sizeof(struct page *) * elems, gfp_mask); + + for (i = 0; i < elems; i++) { + array[i] = page_pool_alloc_pages(pp, gfp_mask); + } + for (i = 0; i < elems; i++) { + _page_pool_put_page(pp, array[i], false); + } + + kfree(array); +} + +enum test_type { type_fast_path, type_ptr_ring, type_page_allocator }; + +/* Depends on compile optimizing this function */ +static __always_inline int time_bench_page_pool(struct time_bench_record *rec, + void *data, enum test_type type, + const char *func) +{ + uint64_t loops_cnt = 0; + gfp_t gfp_mask = GFP_ATOMIC; /* GFP_ATOMIC is not really needed */ + int i, err; + + struct page_pool *pp; + struct page *page; + + struct page_pool_params pp_params = { + .order = 0, + .flags = 0, + .pool_size = MY_POOL_SIZE, + .nid = NUMA_NO_NODE, + .dev = NULL, /* Only use for DMA mapping */ + .dma_dir = DMA_BIDIRECTIONAL, + }; + + pp = page_pool_create(&pp_params); + if (IS_ERR(pp)) { + err = PTR_ERR(pp); + pr_warn("%s: Error(%d) creating page_pool\n", func, err); + goto out; + } + pp_fill_ptr_ring(pp, 64); + + if (in_serving_softirq()) + pr_warn("%s(): in_serving_softirq fast-path\n", func); + else + pr_warn("%s(): Cannot use page_pool fast-path\n", func); + + time_bench_start(rec); + /** Loop to measure **/ + for (i = 0; i < rec->loops; i++) { + /* Common fast-path alloc, that depend on in_serving_softirq() */ + page = page_pool_alloc_pages(pp, gfp_mask); + if (!page) + break; + loops_cnt++; + barrier(); /* avoid compiler to optimize this loop */ + + /* The benchmarks purpose it to test different return paths. + * Compiler should inline optimize other function calls out + */ + if (type == type_fast_path) { + /* Fast-path recycling e.g. XDP_DROP use-case */ + page_pool_recycle_direct(pp, page); + + } else if (type == type_ptr_ring) { + /* Normal return path */ + _page_pool_put_page(pp, page, false); + + } else if (type == type_page_allocator) { + /* Test if not pages are recycled, but instead + * returned back into systems page allocator + */ + get_page(page); /* cause no-recycling */ + _page_pool_put_page(pp, page, false); + put_page(page); + } else { + BUILD_BUG(); + } + } + time_bench_stop(rec, loops_cnt); +out: + page_pool_destroy(pp); + return loops_cnt; +} + +static int time_bench_page_pool01_fast_path(struct time_bench_record *rec, + void *data) +{ + return time_bench_page_pool(rec, data, type_fast_path, __func__); +} + +static int time_bench_page_pool02_ptr_ring(struct time_bench_record *rec, + void *data) +{ + return time_bench_page_pool(rec, data, type_ptr_ring, __func__); +} + +static int time_bench_page_pool03_slow(struct time_bench_record *rec, + void *data) +{ + return time_bench_page_pool(rec, data, type_page_allocator, __func__); +} + +static int run_benchmark_tests(void) +{ + uint32_t nr_loops = loops; + int passed_count = 0; + + /* Baseline tests */ + if (enabled(bit_run_bench_baseline)) { + time_bench_loop(nr_loops * 10, 0, "for_loop", NULL, + time_bench_for_loop); + time_bench_loop(nr_loops * 10, 0, "atomic_inc", NULL, + time_bench_atomic_inc); + time_bench_loop(nr_loops, 0, "lock", NULL, time_bench_lock); + } + + /* This test cannot activate correct code path, due to no-softirq ctx */ + if (enabled(bit_run_bench_no_softirq01)) + time_bench_loop(nr_loops, 0, "no-softirq-page_pool01", NULL, + time_bench_page_pool01_fast_path); + if (enabled(bit_run_bench_no_softirq02)) + time_bench_loop(nr_loops, 0, "no-softirq-page_pool02", NULL, + time_bench_page_pool02_ptr_ring); + if (enabled(bit_run_bench_no_softirq03)) + time_bench_loop(nr_loops, 0, "no-softirq-page_pool03", NULL, + time_bench_page_pool03_slow); + + return passed_count; +} + +static int __init bench_page_pool_simple_module_init(void) +{ + if (verbose) + pr_info("Loaded\n"); + + if (loops > U32_MAX) { + pr_err("Module param loops(%lu) exceeded U32_MAX(%u)\n", loops, + U32_MAX); + return -ECHRNG; + } + + run_benchmark_tests(); + + return 0; +} +module_init(bench_page_pool_simple_module_init); + +static void __exit bench_page_pool_simple_module_exit(void) +{ + if (verbose) + pr_info("Unloaded\n"); +} +module_exit(bench_page_pool_simple_module_exit); + +MODULE_DESCRIPTION("Benchmark of page_pool simple cases"); +MODULE_AUTHOR("Jesper Dangaard Brouer <netoptimizer(a)brouer.com>"); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/net/bench/page_pool/test_bench_page_pool.sh b/tools/testing/selftests/net/bench/page_pool/test_bench_page_pool.sh new file mode 100755 index 000000000000..5eb48f28b659 --- /dev/null +++ b/tools/testing/selftests/net/bench/page_pool/test_bench_page_pool.sh @@ -0,0 +1,32 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# + +set -e + +DRIVER="./page_pool/bench_page_pool.ko" +result="" + +function run_test() +{ + rmmod "bench_page_pool.ko" || true + insmod $DRIVER > /dev/null 2>&1 + result=$(dmesg | tail -10) + echo "$result" + + echo + echo "Fast path results:" + echo ${result} | grep -o -E "no-softirq-page_pool01 Per elem: ([0-9]+) cycles$tsc$ ([0-9]+\.[0-9]+) ns" + + echo + echo "ptr_ring results:" + echo ${result} | grep -o -E "no-softirq-page_pool02 Per elem: ([0-9]+) cycles$tsc$ ([0-9]+\.[0-9]+) ns" + + echo + echo "slow path results:" + echo ${result} | grep -o -E "no-softirq-page_pool03 Per elem: ([0-9]+) cycles$tsc$ ([0-9]+\.[0-9]+) ns" +} + +run_test + +exit 0 diff --git a/tools/testing/selftests/net/bench/page_pool/time_bench.c b/tools/testing/selftests/net/bench/page_pool/time_bench.c new file mode 100644 index 000000000000..257b1515c64e --- /dev/null +++ b/tools/testing/selftests/net/bench/page_pool/time_bench.c @@ -0,0 +1,406 @@ +/* + * Benchmarking code execution time inside the kernel + * + * Copyright (C) 2014, Red Hat, Inc., Jesper Dangaard Brouer + * for licensing details see kernel-base/COPYING + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/time.h> + +#include <linux/perf_event.h> /* perf_event_create_kernel_counter() */ + +/* For concurrency testing */ +#include <linux/completion.h> +#include <linux/sched.h> +#include <linux/workqueue.h> +#include <linux/kthread.h> + +#include "time_bench.h" + +static int verbose = 1; + +/** TSC (Time-Stamp Counter) based ** + * See: linux/time_bench.h + * tsc_start_clock() and tsc_stop_clock() + */ + +/** Wall-clock based ** + */ + +/** PMU (Performance Monitor Unit) based ** + */ +#define PERF_FORMAT \ + (PERF_FORMAT_GROUP | PERF_FORMAT_ID | PERF_FORMAT_TOTAL_TIME_ENABLED | \ + PERF_FORMAT_TOTAL_TIME_RUNNING) + +struct raw_perf_event { + uint64_t config; /* event */ + uint64_t config1; /* umask */ + struct perf_event *save; + char *desc; +}; + +/* if HT is enable a maximum of 4 events (5 if one is instructions + * retired can be specified, if HT is disabled a maximum of 8 (9 if + * one is instructions retired) can be specified. + * + * From Table 19-1. Architectural Performance Events + * Architectures Software Developer’s Manual Volume 3: System Programming Guide + */ +struct raw_perf_event perf_events[] = { + { 0x3c, 0x00, NULL, "Unhalted CPU Cycles" }, + { 0xc0, 0x00, NULL, "Instruction Retired" } +}; + +#define NUM_EVTS (sizeof(perf_events) / sizeof(struct raw_perf_event)) + +/* WARNING: PMU config is currently broken! + */ +bool time_bench_PMU_config(bool enable) +{ + int i; + struct perf_event_attr perf_conf; + struct perf_event *perf_event; + int cpu; + + preempt_disable(); + cpu = smp_processor_id(); + pr_info("DEBUG: cpu:%d\n", cpu); + preempt_enable(); + + memset(&perf_conf, 0, sizeof(struct perf_event_attr)); + perf_conf.type = PERF_TYPE_RAW; + perf_conf.size = sizeof(struct perf_event_attr); + perf_conf.read_format = PERF_FORMAT; + perf_conf.pinned = 1; + perf_conf.exclude_user = 1; /* No userspace events */ + perf_conf.exclude_kernel = 0; /* Only kernel events */ + + for (i = 0; i < NUM_EVTS; i++) { + perf_conf.disabled = enable; + //perf_conf.disabled = (i == 0) ? 1 : 0; + perf_conf.config = perf_events[i].config; + perf_conf.config1 = perf_events[i].config1; + if (verbose) + pr_info("%s() enable PMU counter: %s\n", + __func__, perf_events[i].desc); + perf_event = perf_event_create_kernel_counter(&perf_conf, cpu, + NULL /* task */, + NULL /* overflow_handler*/, + NULL /* context */); + if (perf_event) { + perf_events[i].save = perf_event; + pr_info("%s():DEBUG perf_event success\n", __func__); + + perf_event_enable(perf_event); + } else { + pr_info("%s():DEBUG perf_event is NULL\n", __func__); + } + } + + return true; +} + +/** Generic functions ** + */ + +/* Calculate stats, store results in record */ +bool time_bench_calc_stats(struct time_bench_record *rec) +{ +#define NANOSEC_PER_SEC 1000000000 /* 10^9 */ + uint64_t ns_per_call_tmp_rem = 0; + uint32_t ns_per_call_remainder = 0; + uint64_t pmc_ipc_tmp_rem = 0; + uint32_t pmc_ipc_remainder = 0; + uint32_t pmc_ipc_div = 0; + uint32_t invoked_cnt_precision = 0; + uint32_t invoked_cnt = 0; /* 32-bit due to div_u64_rem() */ + + if (rec->flags & TIME_BENCH_LOOP) { + if (rec->invoked_cnt < 1000) { + pr_err("ERR: need more(>1000) loops(%llu) for timing\n", + rec->invoked_cnt); + return false; + } + if (rec->invoked_cnt > ((1ULL << 32) - 1)) { + /* div_u64_rem() can only support div with 32bit*/ + pr_err("ERR: Invoke cnt(%llu) too big overflow 32bit\n", + rec->invoked_cnt); + return false; + } + invoked_cnt = (uint32_t)rec->invoked_cnt; + } + + /* TSC (Time-Stamp Counter) records */ + if (rec->flags & TIME_BENCH_TSC) { + rec->tsc_interval = rec->tsc_stop - rec->tsc_start; + if (rec->tsc_interval == 0) { + pr_err("ABORT: timing took ZERO TSC time\n"); + return false; + } + /* Calculate stats */ + if (rec->flags & TIME_BENCH_LOOP) + rec->tsc_cycles = rec->tsc_interval / invoked_cnt; + else + rec->tsc_cycles = rec->tsc_interval; + } + + /* Wall-clock time calc */ + if (rec->flags & TIME_BENCH_WALLCLOCK) { + rec->time_start = rec->ts_start.tv_nsec + + (NANOSEC_PER_SEC * rec->ts_start.tv_sec); + rec->time_stop = rec->ts_stop.tv_nsec + + (NANOSEC_PER_SEC * rec->ts_stop.tv_sec); + rec->time_interval = rec->time_stop - rec->time_start; + if (rec->time_interval == 0) { + pr_err("ABORT: timing took ZERO wallclock time\n"); + return false; + } + /* Calculate stats */ + /*** Division in kernel it tricky ***/ + /* Orig: time_sec = (time_interval / NANOSEC_PER_SEC); */ + /* remainder only correct because NANOSEC_PER_SEC is 10^9 */ + rec->time_sec = div_u64_rem(rec->time_interval, NANOSEC_PER_SEC, + &rec->time_sec_remainder); + //TODO: use existing struct timespec records instead of div? + + if (rec->flags & TIME_BENCH_LOOP) { + /*** Division in kernel it tricky ***/ + /* Orig: ns = ((double)time_interval / invoked_cnt); */ + /* First get quotient */ + rec->ns_per_call_quotient = + div_u64_rem(rec->time_interval, invoked_cnt, + &ns_per_call_remainder); + /* Now get decimals .xxx precision (incorrect roundup)*/ + ns_per_call_tmp_rem = ns_per_call_remainder; + invoked_cnt_precision = invoked_cnt / 1000; + if (invoked_cnt_precision > 0) { + rec->ns_per_call_decimal = + div_u64_rem(ns_per_call_tmp_rem, + invoked_cnt_precision, + &ns_per_call_remainder); + } + } + } + + /* Performance Monitor Unit (PMU) counters */ + if (rec->flags & TIME_BENCH_PMU) { + //FIXME: Overflow handling??? + rec->pmc_inst = rec->pmc_inst_stop - rec->pmc_inst_start; + rec->pmc_clk = rec->pmc_clk_stop - rec->pmc_clk_start; + + /* Calc Instruction Per Cycle (IPC) */ + /* First get quotient */ + rec->pmc_ipc_quotient = div_u64_rem(rec->pmc_inst, rec->pmc_clk, + &pmc_ipc_remainder); + /* Now get decimals .xxx precision (incorrect roundup)*/ + pmc_ipc_tmp_rem = pmc_ipc_remainder; + pmc_ipc_div = rec->pmc_clk / 1000; + if (pmc_ipc_div > 0) { + rec->pmc_ipc_decimal = div_u64_rem(pmc_ipc_tmp_rem, + pmc_ipc_div, + &pmc_ipc_remainder); + } + } + + return true; +} + +/* Generic function for invoking a loop function and calculating + * execution time stats. The function being called/timed is assumed + * to perform a tight loop, and update the timing record struct. + */ +bool time_bench_loop(uint32_t loops, int step, char *txt, void *data, + int (*func)(struct time_bench_record *record, void *data)) +{ + struct time_bench_record rec; + + /* Setup record */ + memset(&rec, 0, sizeof(rec)); /* zero func might not update all */ + rec.version_abi = 1; + rec.loops = loops; + rec.step = step; + rec.flags = (TIME_BENCH_LOOP|TIME_BENCH_TSC|TIME_BENCH_WALLCLOCK); +// rec.flags = (TIME_BENCH_LOOP|TIME_BENCH_TSC| +// TIME_BENCH_WALLCLOCK|TIME_BENCH_PMU); + //TODO: Add/copy txt to rec + + /*** Loop function being timed ***/ + if (!func(&rec, data)) { + pr_err("ABORT: function being timed failed\n"); + return false; + } + + if (rec.invoked_cnt < loops) + pr_warn("WARNING: Invoke count(%llu) smaller than loops(%d)\n", + rec.invoked_cnt, loops); + + /* Calculate stats */ + time_bench_calc_stats(&rec); + + pr_info("Type:%s Per elem: %llu cycles(tsc) %llu.%03llu ns (step:%d)" + " - (measurement period time:%llu.%09u sec time_interval:%llu)" + " - (invoke count:%llu tsc_interval:%llu)\n", + txt, rec.tsc_cycles, + rec.ns_per_call_quotient, rec.ns_per_call_decimal, rec.step, + rec.time_sec, rec.time_sec_remainder, rec.time_interval, + rec.invoked_cnt, rec.tsc_interval); +/* pr_info("DEBUG check is %llu/%llu == %llu.%03llu ?\n", + rec.time_interval, rec.invoked_cnt, + rec.ns_per_call_quotient, rec.ns_per_call_decimal); +*/ + if (rec.flags & TIME_BENCH_PMU) { + pr_info("Type:%s PMU inst/clock" + "%llu/%llu = %llu.%03llu IPC (inst per cycle)\n", + txt, rec.pmc_inst, rec.pmc_clk, + rec.pmc_ipc_quotient, rec.pmc_ipc_decimal); + } + return true; +} + +/* Function getting invoked by kthread */ +static int invoke_test_on_cpu_func(void *private) +{ + struct time_bench_cpu *cpu = private; + struct time_bench_sync *sync = cpu->sync; + cpumask_t newmask = CPU_MASK_NONE; + void *data = cpu->data; + + /* Restrict CPU */ + cpumask_set_cpu(cpu->rec.cpu, &newmask); + set_cpus_allowed_ptr(current, &newmask); + + /* Synchronize start of concurrency test */ + atomic_inc(&sync->nr_tests_running); + wait_for_completion(&sync->start_event); + + /* Start benchmark function */ + if (!cpu->bench_func(&cpu->rec, data)) { + pr_err("ERROR: function being timed failed on CPU:%d(%d)\n", + cpu->rec.cpu, smp_processor_id()); + } else { + if (verbose) + pr_info("SUCCESS: ran on CPU:%d(%d)\n", cpu->rec.cpu, + smp_processor_id()); + } + cpu->did_bench_run = true; + + /* End test */ + atomic_dec(&sync->nr_tests_running); + /* Wait for kthread_stop() telling us to stop */ + while (!kthread_should_stop()) { + set_current_state(TASK_INTERRUPTIBLE); + schedule(); + } + __set_current_state(TASK_RUNNING); + return 0; +} + +void time_bench_print_stats_cpumask(const char *desc, + struct time_bench_cpu *cpu_tasks, + const struct cpumask *mask) +{ + uint64_t average = 0; + int cpu; + int step = 0; + struct sum { + uint64_t tsc_cycles; + int records; + } sum = { 0 }; + + /* Get stats */ + for_each_cpu(cpu, mask) { + struct time_bench_cpu *c = &cpu_tasks[cpu]; + struct time_bench_record *rec = &c->rec; + + /* Calculate stats */ + time_bench_calc_stats(rec); + + pr_info("Type:%s CPU(%d) %llu cycles(tsc) %llu.%03llu ns" + " (step:%d)" + " - (measurement period time:%llu.%09u sec time_interval:%llu)" + " - (invoke count:%llu tsc_interval:%llu)\n", + desc, cpu, rec->tsc_cycles, rec->ns_per_call_quotient, + rec->ns_per_call_decimal, rec->step, rec->time_sec, + rec->time_sec_remainder, rec->time_interval, + rec->invoked_cnt, rec->tsc_interval); + + /* Collect average */ + sum.records++; + sum.tsc_cycles += rec->tsc_cycles; + step = rec->step; + } + + if (sum.records) /* avoid div-by-zero */ + average = sum.tsc_cycles / sum.records; + pr_info("Sum Type:%s Average: %llu cycles(tsc) CPUs:%d step:%d\n", desc, + average, sum.records, step); +} + +void time_bench_run_concurrent( + uint32_t loops, int step, void *data, + const struct cpumask *mask, /* Support masking outsome CPUs*/ + struct time_bench_sync *sync, struct time_bench_cpu *cpu_tasks, + int (*func)(struct time_bench_record *record, void *data)) +{ + int cpu, running = 0; + + if (verbose) // DEBUG + pr_warn("%s() Started on CPU:%d\n", __func__, + smp_processor_id()); + + /* Reset sync conditions */ + atomic_set(&sync->nr_tests_running, 0); + init_completion(&sync->start_event); + + /* Spawn off jobs on all CPUs */ + for_each_cpu(cpu, mask) { + struct time_bench_cpu *c = &cpu_tasks[cpu]; + + running++; + c->sync = sync; /* Send sync variable along */ + c->data = data; /* Send opaque along */ + + /* Init benchmark record */ + memset(&c->rec, 0, sizeof(struct time_bench_record)); + c->rec.version_abi = 1; + c->rec.loops = loops; + c->rec.step = step; + c->rec.flags = (TIME_BENCH_LOOP|TIME_BENCH_TSC| + TIME_BENCH_WALLCLOCK); + c->rec.cpu = cpu; + c->bench_func = func; + c->task = kthread_run(invoke_test_on_cpu_func, c, + "time_bench%d", cpu); + if (IS_ERR(c->task)) { + pr_err("%s(): Failed to start test func\n", __func__); + return; /* Argh, what about cleanup?! */ + } + } + + /* Wait until all processes are running */ + while (atomic_read(&sync->nr_tests_running) < running) { + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(10); + } + /* Kick off all CPU concurrently on completion event */ + complete_all(&sync->start_event); + + /* Wait for CPUs to finish */ + while (atomic_read(&sync->nr_tests_running)) { + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(10); + } + + /* Stop the kthreads */ + for_each_cpu(cpu, mask) { + struct time_bench_cpu *c = &cpu_tasks[cpu]; + kthread_stop(c->task); + } + + if (verbose) // DEBUG - happens often, finish on another CPU + pr_warn("%s() Finished on CPU:%d\n", __func__, + smp_processor_id()); +} diff --git a/tools/testing/selftests/net/bench/page_pool/time_bench.h b/tools/testing/selftests/net/bench/page_pool/time_bench.h new file mode 100644 index 000000000000..7331b5789490 --- /dev/null +++ b/tools/testing/selftests/net/bench/page_pool/time_bench.h @@ -0,0 +1,259 @@ +/* + * Benchmarking code execution time inside the kernel + * + * Copyright (C) 2014, Red Hat, Inc., Jesper Dangaard Brouer + * for licensing details see kernel-base/COPYING + */ +#ifndef _LINUX_TIME_BENCH_H +#define _LINUX_TIME_BENCH_H + +/* Main structure used for recording a benchmark run */ +struct time_bench_record { + uint32_t version_abi; + uint32_t loops; /* Requested loop invocations */ + uint32_t step; /* option for e.g. bulk invocations */ + + uint32_t flags; /* Measurements types enabled */ +#define TIME_BENCH_LOOP (1<<0) +#define TIME_BENCH_TSC (1<<1) +#define TIME_BENCH_WALLCLOCK (1<<2) +#define TIME_BENCH_PMU (1<<3) + + uint32_t cpu; /* Used when embedded in time_bench_cpu */ + + /* Records */ + uint64_t invoked_cnt; /* Returned actual invocations */ + uint64_t tsc_start; + uint64_t tsc_stop; + struct timespec64 ts_start; + struct timespec64 ts_stop; + /** PMU counters for instruction and cycles + * instructions counter including pipelined instructions */ + uint64_t pmc_inst_start; + uint64_t pmc_inst_stop; + /* CPU unhalted clock counter */ + uint64_t pmc_clk_start; + uint64_t pmc_clk_stop; + + /* Result records */ + uint64_t tsc_interval; + uint64_t time_start, time_stop, time_interval; /* in nanosec */ + uint64_t pmc_inst, pmc_clk; + + /* Derived result records */ + uint64_t tsc_cycles; // +decimal? + uint64_t ns_per_call_quotient, ns_per_call_decimal; + uint64_t time_sec; + uint32_t time_sec_remainder; + uint64_t pmc_ipc_quotient, pmc_ipc_decimal; /* inst per cycle */ +}; + +/* For synchronizing parallel CPUs to run concurrently */ +struct time_bench_sync { + atomic_t nr_tests_running; + struct completion start_event; +}; + +/* Keep track of CPUs executing our bench function. + * + * Embed a time_bench_record for storing info per cpu + */ +struct time_bench_cpu { + struct time_bench_record rec; + struct time_bench_sync *sync; /* back ptr */ + struct task_struct *task; + /* "data" opaque could have been placed in time_bench_sync, + * but to avoid any false sharing, place it per CPU + */ + void *data; + /* Support masking outsome CPUs, mark if it ran */ + bool did_bench_run; + /* int cpu; // note CPU stored in time_bench_record */ + int (*bench_func)(struct time_bench_record *record, void *data); +}; + +/* + * Below TSC assembler code is not compatible with other archs, and + * can also fail on guests if cpu-flags are not correct. + * + * The way TSC reading is used, many iterations, does not require as + * high accuracy as described below (in Intel Doc #324264). + * + * Considering changing to use get_cycles() (#include <asm/timex.h>). + */ + +/** TSC (Time-Stamp Counter) based ** + * Recommend reading, to understand details of reading TSC accurately: + * Intel Doc #324264, "How to Benchmark Code Execution Times on Intel" + * + * Consider getting exclusive ownership of CPU by using: + * unsigned long flags; + * preempt_disable(); + * raw_local_irq_save(flags); + * _your_code_ + * raw_local_irq_restore(flags); + * preempt_enable(); + * + * Clobbered registers: "%rax", "%rbx", "%rcx", "%rdx" + * RDTSC only change "%rax" and "%rdx" but + * CPUID clears the high 32-bits of all (rax/rbx/rcx/rdx) + */ +static __always_inline uint64_t tsc_start_clock(void) +{ + /* See: Intel Doc #324264 */ + unsigned hi, lo; + asm volatile("CPUID\n\t" + "RDTSC\n\t" + "mov %%edx, %0\n\t" + "mov %%eax, %1\n\t" + : "=r"(hi), "=r"(lo)::"%rax", "%rbx", "%rcx", "%rdx"); + //FIXME: on 32bit use clobbered %eax + %edx + return ((uint64_t)lo) | (((uint64_t)hi) << 32); +} + +static __always_inline uint64_t tsc_stop_clock(void) +{ + /* See: Intel Doc #324264 */ + unsigned hi, lo; + asm volatile("RDTSCP\n\t" + "mov %%edx, %0\n\t" + "mov %%eax, %1\n\t" + "CPUID\n\t" + : "=r"(hi), "=r"(lo)::"%rax", "%rbx", "%rcx", "%rdx"); + return ((uint64_t)lo) | (((uint64_t)hi) << 32); +} + +/* Notes for RDTSC and RDTSCP + * + * Hannes found out that __builtin_ia32_rdtsc and + * __builtin_ia32_rdtscp are undocumented available in gcc, so there + * is no need to write inline assembler functions for them any more. + * + * unsigned long long __builtin_ia32_rdtscp(unsigned int *foo); + * (where foo is set to: numa_node << 12 | cpu) + * and + * unsigned long long __builtin_ia32_rdtsc(void); + * + * Above we combine the calls with CPUID, thus I don't see how this is + * directly appreciable. + */ + +/* +inline uint64_t rdtsc(void) +{ + uint32_t low, high; + asm volatile("rdtsc" : "=a" (low), "=d" (high)); + return low | (((uint64_t )high ) << 32); +} +*/ + +/** Wall-clock based ** + * + * use: getnstimeofday() + * getnstimeofday(&rec->ts_start); + * getnstimeofday(&rec->ts_stop); + * + * API changed see: Documentation/core-api/timekeeping.rst + * https://www.kernel.org/doc/html/latest/core-api/timekeeping.html#c.getnstim… + * + * We should instead use: ktime_get_real_ts64() is a direct + * replacement, but consider using monotonic time (ktime_get_ts64()) + * and/or a ktime_t based interface (ktime_get()/ktime_get_real()). + */ + +/** PMU (Performance Monitor Unit) based ** + * + * Needed for calculating: Instructions Per Cycle (IPC) + * - The IPC number tell how efficient the CPU pipelining were + */ +//lookup: perf_event_create_kernel_counter() + +bool time_bench_PMU_config(bool enable); + +/* Raw reading via rdpmc() using fixed counters + * + * From: https://github.com/andikleen/simple-pmu + */ +enum { + FIXED_SELECT = (1U << 30), /* == 0x40000000 */ + FIXED_INST_RETIRED_ANY = 0, + FIXED_CPU_CLK_UNHALTED_CORE = 1, + FIXED_CPU_CLK_UNHALTED_REF = 2, +}; + +static __always_inline unsigned long long p_rdpmc(unsigned in) +{ + unsigned d, a; + + asm volatile("rdpmc" : "=d"(d), "=a"(a) : "c"(in) : "memory"); + return ((unsigned long long)d << 32) | a; +} + +/* These PMU counter needs to be enabled, but I don't have the + * configure code implemented. My current hack is running: + * sudo perf stat -e cycles:k -e instructions:k insmod lib/ring_queue_test.ko + */ +/* Reading all pipelined instruction */ +static __always_inline unsigned long long pmc_inst(void) +{ + return p_rdpmc(FIXED_SELECT | FIXED_INST_RETIRED_ANY); +} + +/* Reading CPU clock cycles */ +static __always_inline unsigned long long pmc_clk(void) +{ + return p_rdpmc(FIXED_SELECT | FIXED_CPU_CLK_UNHALTED_CORE); +} + +/* Raw reading via MSR rdmsr() is likely wrong + * FIXME: How can I know which raw MSR registers are conf for what? + */ +#define MSR_IA32_PCM0 0x400000C1 /* PERFCTR0 */ +#define MSR_IA32_PCM1 0x400000C2 /* PERFCTR1 */ +#define MSR_IA32_PCM2 0x400000C3 +static inline uint64_t msr_inst(unsigned long long *msr_result) +{ + return rdmsrl_safe(MSR_IA32_PCM0, msr_result); +} + +/** Generic functions ** + */ +bool time_bench_loop(uint32_t loops, int step, char *txt, void *data, + int (*func)(struct time_bench_record *rec, void *data)); +bool time_bench_calc_stats(struct time_bench_record *rec); + +void time_bench_run_concurrent( + uint32_t loops, int step, void *data, + const struct cpumask *mask, /* Support masking outsome CPUs*/ + struct time_bench_sync *sync, struct time_bench_cpu *cpu_tasks, + int (*func)(struct time_bench_record *record, void *data)); +void time_bench_print_stats_cpumask(const char *desc, + struct time_bench_cpu *cpu_tasks, + const struct cpumask *mask); + +//FIXME: use rec->flags to select measurement, should be MACRO +static __always_inline void time_bench_start(struct time_bench_record *rec) +{ + //getnstimeofday(&rec->ts_start); + ktime_get_real_ts64(&rec->ts_start); + if (rec->flags & TIME_BENCH_PMU) { + rec->pmc_inst_start = pmc_inst(); + rec->pmc_clk_start = pmc_clk(); + } + rec->tsc_start = tsc_start_clock(); +} + +static __always_inline void time_bench_stop(struct time_bench_record *rec, + uint64_t invoked_cnt) +{ + rec->tsc_stop = tsc_stop_clock(); + if (rec->flags & TIME_BENCH_PMU) { + rec->pmc_inst_stop = pmc_inst(); + rec->pmc_clk_stop = pmc_clk(); + } + //getnstimeofday(&rec->ts_stop); + ktime_get_real_ts64(&rec->ts_stop); + rec->invoked_cnt = invoked_cnt; +} + +#endif /* _LINUX_TIME_BENCH_H */ base-commit: ea15e046263b19e91ffd827645ae5dfa44ebd044 -- 2.49.0.1151.ga128411c76-goog

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