@@ -21,4 +21,10 @@ int make_swapfile(const char *swapfile, int blocks, int safe);
* we are testing on.
*/
bool is_swap_supported(const char *filename);
+
+/*
+ * Get kernel constant MAX_SWAPFILES value
+ */
+int tst_max_swapfiles(void);
+
#endif /* __LIBSWAP_H__ */
@@ -16,6 +16,8 @@
#include "tst_test.h"
#include "libswap.h"
#include "lapi/syscalls.h"
+#include "tst_kconfig.h"
+#include "tst_safe_stdio.h"
static const char *const swap_supported_fs[] = {
"btrfs",
@@ -217,3 +219,45 @@ bool is_swap_supported(const char *filename)
return true;
}
+
+/*
+ * Get kernel constant MAX_SWAPFILES value
+ */
+int tst_max_swapfiles(void)
+{
+ unsigned int max_swapfile = 32;
+ unsigned int swp_migration_num = 0, swp_hwpoison_num = 0, swp_device_num = 0, swp_pte_marker_num = 0;
+ struct tst_kconfig_var migration_kconfig = TST_KCONFIG_INIT("CONFIG_MIGRATION");
+ struct tst_kconfig_var memory_kconfig = TST_KCONFIG_INIT("CONFIG_MEMORY_FAILURE");
+ struct tst_kconfig_var device_kconfig = TST_KCONFIG_INIT("CONFIG_DEVICE_PRIVATE");
+ struct tst_kconfig_var marker_kconfig = TST_KCONFIG_INIT("CONFIG_PTE_MARKER");
+
+ tst_kconfig_read(&migration_kconfig, 1);
+ tst_kconfig_read(&memory_kconfig, 1);
+ tst_kconfig_read(&device_kconfig, 1);
+ tst_kconfig_read(&marker_kconfig, 1);
+
+ if (migration_kconfig.choice == 'y') {
+ if (tst_kvercmp(5, 19, 0) < 0)
+ swp_migration_num = 2;
+ else
+ swp_migration_num = 3;
+ }
+
+ if (memory_kconfig.choice == 'y')
+ swp_hwpoison_num = 1;
+
+ if (device_kconfig.choice == 'y') {
+ if (tst_kvercmp(4, 14, 0) >= 0)
+ swp_device_num = 2;
+ if (tst_kvercmp(5, 14, 0) >= 0)
+ swp_device_num = 4;
+ }
+
+ if (marker_kconfig.choice == 'y') {
+ if (tst_kvercmp(5, 19, 0) >= 0)
+ swp_pte_marker_num = 1;
+ }
+
+ return max_swapfile - swp_migration_num - swp_hwpoison_num - swp_device_num - swp_pte_marker_num;
+}
Current, the kernel constant MAX_SWAPFILES value is calculated as below ------------------------------------ //#ifdef CONFIG_DEVICE_PRIVATE //#define SWP_DEVICE_NUM 4 //#else //#define SWP_DEVICE_NUM 0 //#endif //#ifdef CONFIG_MIGRATION //#define SWP_MIGRATION_NUM 3 //#else //#define SWP_MIGRATION_NUM 0 //#ifdef CONFIG_MEMORY_FAILURE //#define SWP_HWPOISON_NUM 1 //#else //#define SWP_HWPOISON_NUM 0 //#endif //#define SWP_PTE_MARKER_NUM 1 //#define MAX_SWAPFILES_SHIFT 5 //#define MAX_SWAPFILES \ // ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ // SWP_MIGRATION_NUM - SWP_HWPOISON_NUM - \ // SWP_PTE_MARKER_NUM) ------------------------------------ Also, man-pages missed something after 5.14 kernel. I have sent two patches[1][2] to add it. The kernel patches modify this kernel constant in[3][4][5][6]. [1]https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=26f3ec74e [2]https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=6bf3937fc [3]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/include/linux/swap.h?id=5042db43cc [4]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/include/linux/swap.h?id=b756a3b5e [5]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/include/linux/swap.h?id=679d10331 [6]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/include/linux/swap.h?id=6c287605f Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com> --- include/libswap.h | 6 ++++++ libs/libltpswap/libswap.c | 44 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+)