diff options
| author | Uladzislau Rezki (Sony) <urezki@gmail.com> | 2025-04-17 18:12:13 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-05-11 17:48:33 -0700 |
| commit | 7a73348e5d4715b5565a53f21c01ea7b54e46cbd (patch) | |
| tree | e498a3160b0a444ab7a81b81d5944af3257b1fb9 /lib/test_vmalloc.c | |
| parent | b05f8d7e077952d14acb63e3ccdf5f64404b59a4 (diff) | |
lib/test_vmalloc.c: replace RWSEM to SRCU for setup
The test has the initialization step during which threads are created. To
prevent the workers from starting prematurely a write lock was previously
used by the main setup thread, while each worker would block on a read
lock.
Replace this RWSEM based synchronization with a simpler SRCU based
approach. Which does two basic steps:
- Main thread wraps the setup phase in an SRCU read-side critical
section. Pair of srcu_read_lock()/srcu_read_unlock().
- Each worker calls synchronize_srcu() on entry, ensuring it waits for
the initialization phase to be completed.
This patch eliminates the need for down_read()/up_read() and
down_write()/up_write() pairs thus simplifying the logic and improving
clarity.
[urezki@gmail.com: fix compile error with CONFIG_TINY_RCU]
Link: https://lkml.kernel.org/r/20250420142029.103169-1-urezki@gmail.com
Link: https://lkml.kernel.org/r/20250417161216.88318-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Adrian Huang <ahuang12@lenovo.com>
Tested-by: Adrian Huang <ahuang12@lenovo.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Christop Hellwig <hch@infradead.org>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/test_vmalloc.c')
| -rw-r--r-- | lib/test_vmalloc.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/lib/test_vmalloc.c b/lib/test_vmalloc.c index f585949ff696..399751022eea 100644 --- a/lib/test_vmalloc.c +++ b/lib/test_vmalloc.c @@ -13,9 +13,9 @@ #include <linux/moduleparam.h> #include <linux/completion.h> #include <linux/delay.h> -#include <linux/rwsem.h> #include <linux/mm.h> #include <linux/rcupdate.h> +#include <linux/srcu.h> #include <linux/slab.h> #define __param(type, name, init, msg) \ @@ -58,10 +58,9 @@ __param(int, run_test_mask, INT_MAX, ); /* - * Read write semaphore for synchronization of setup - * phase that is done in main thread and workers. + * This is for synchronization of setup phase. */ -static DECLARE_RWSEM(prepare_for_test_rwsem); +DEFINE_STATIC_SRCU(prepare_for_test_srcu); /* * Completion tracking for worker threads. @@ -458,7 +457,7 @@ static int test_func(void *private) /* * Block until initialization is done. */ - down_read(&prepare_for_test_rwsem); + synchronize_srcu(&prepare_for_test_srcu); t->start = get_cycles(); for (i = 0; i < ARRAY_SIZE(test_case_array); i++) { @@ -487,8 +486,6 @@ static int test_func(void *private) t->data[index].time = delta; } t->stop = get_cycles(); - - up_read(&prepare_for_test_rwsem); test_report_one_done(); /* @@ -526,7 +523,7 @@ init_test_configuration(void) static void do_concurrent_test(void) { - int i, ret; + int i, ret, idx; /* * Set some basic configurations plus sanity check. @@ -538,7 +535,7 @@ static void do_concurrent_test(void) /* * Put on hold all workers. */ - down_write(&prepare_for_test_rwsem); + idx = srcu_read_lock(&prepare_for_test_srcu); for (i = 0; i < nr_threads; i++) { struct test_driver *t = &tdriver[i]; @@ -555,7 +552,7 @@ static void do_concurrent_test(void) /* * Now let the workers do their job. */ - up_write(&prepare_for_test_rwsem); + srcu_read_unlock(&prepare_for_test_srcu, idx); /* * Sleep quiet until all workers are done with 1 second |