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Message-Id: <20240319172609.332900-4-gregory.price@memverge.com>
Date: Tue, 19 Mar 2024 13:26:09 -0400
From: Gregory Price <gourry.memverge@...il.com>
To: linux-mm@...ck.org
Cc: linux-api@...r.kernel.org,
linux-arch@...r.kernel.org,
linux-kselftest@...r.kernel.org,
linux-kernel@...r.kernel.org,
ying.huang@...el.com,
dan.j.williams@...el.com,
honggyu.kim@...com,
corbet@....net,
arnd@...db.de,
luto@...nel.org,
akpm@...ux-foundation.org,
shuah@...nel.org,
Gregory Price <gregory.price@...verge.com>
Subject: [RFC v3 3/3] ktest: sys_move_phys_pages ktest
Implement simple ktest that looks up the physical address via
/proc/self/pagemap and migrates the page based on that information.
Signed-off-by: Gregory Price <gregory.price@...verge.com>
---
tools/testing/selftests/mm/migration.c | 99 ++++++++++++++++++++++++++
1 file changed, 99 insertions(+)
diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c
index 6908569ef406..c005c98dbdc1 100644
--- a/tools/testing/selftests/mm/migration.c
+++ b/tools/testing/selftests/mm/migration.c
@@ -5,6 +5,8 @@
*/
#include "../kselftest_harness.h"
+#include <stdint.h>
+#include <stdio.h>
#include <strings.h>
#include <pthread.h>
#include <numa.h>
@@ -14,11 +16,17 @@
#include <sys/types.h>
#include <signal.h>
#include <time.h>
+#include <unistd.h>
#define TWOMEG (2<<20)
#define RUNTIME (20)
+#define GET_BIT(X, Y) ((X & ((uint64_t)1<<Y)) >> Y)
+#define GET_PFN(X) (X & 0x7FFFFFFFFFFFFFull)
#define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1)))
+#define PAGEMAP_ENTRY 8
+const int __endian_bit = 1;
+#define is_bigendian() ((*(char *)&__endian_bit) == 0)
FIXTURE(migration)
{
@@ -94,6 +102,45 @@ int migrate(uint64_t *ptr, int n1, int n2)
return 0;
}
+int migrate_phys(uint64_t paddr, int n1, int n2)
+{
+ int ret, tmp;
+ int status = 0;
+ struct timespec ts1, ts2;
+
+ if (clock_gettime(CLOCK_MONOTONIC, &ts1))
+ return -1;
+
+ while (1) {
+ if (clock_gettime(CLOCK_MONOTONIC, &ts2))
+ return -1;
+
+ if (ts2.tv_sec - ts1.tv_sec >= RUNTIME)
+ return 0;
+
+ /*
+ * FIXME: move_phys_pages was syscall 462 during RFC.
+ * Update this when an official syscall number is adopted
+ * and the libnuma interface is implemented.
+ */
+ ret = syscall(462, 1, (void **) &paddr, &n2, &status,
+ MPOL_MF_MOVE_ALL);
+ if (ret) {
+ if (ret > 0)
+ printf("Didn't migrate %d pages\n", ret);
+ else
+ perror("Couldn't migrate pages");
+ return -2;
+ }
+
+ tmp = n2;
+ n2 = n1;
+ n1 = tmp;
+ }
+
+ return 0;
+}
+
void *access_mem(void *ptr)
{
volatile uint64_t y = 0;
@@ -199,4 +246,56 @@ TEST_F_TIMEOUT(migration, private_anon_thp, 2*RUNTIME)
ASSERT_EQ(pthread_cancel(self->threads[i]), 0);
}
+/*
+ * Same as the basic migration, but test move_phys_pages.
+ */
+TEST_F_TIMEOUT(migration, phys_addr, 2*RUNTIME)
+{
+ uint64_t *ptr;
+ uint64_t pagemap_val, paddr, file_offset;
+ unsigned char c_buf[PAGEMAP_ENTRY];
+ int i, c, status;
+ FILE *f;
+
+ if (self->nthreads < 2 || self->n1 < 0 || self->n2 < 0)
+ SKIP(return, "Not enough threads or NUMA nodes available");
+
+ ptr = mmap(NULL, TWOMEG, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+
+ memset(ptr, 0xde, TWOMEG);
+
+ /* PFN of ptr from /proc/self/pagemap */
+ f = fopen("/proc/self/pagemap", "rb");
+ file_offset = ((uint64_t)ptr) / getpagesize() * PAGEMAP_ENTRY;
+ status = fseek(f, file_offset, SEEK_SET);
+ ASSERT_EQ(status, 0);
+ for (i = 0; i < PAGEMAP_ENTRY; i++) {
+ c = getc(f);
+ ASSERT_NE(c, EOF);
+ /* handle endiand differences */
+ if (is_bigendian())
+ c_buf[i] = c;
+ else
+ c_buf[PAGEMAP_ENTRY - i - 1] = c;
+ }
+ fclose(f);
+
+ for (i = 0; i < PAGEMAP_ENTRY; i++)
+ pagemap_val = (pagemap_val << 8) + c_buf[i];
+
+ ASSERT_TRUE(GET_BIT(pagemap_val, 63));
+ /* This reports a pfn, we need to shift this by page size */
+ paddr = GET_PFN(pagemap_val) << __builtin_ctz(getpagesize());
+
+ for (i = 0; i < self->nthreads - 1; i++)
+ if (pthread_create(&self->threads[i], NULL, access_mem, ptr))
+ perror("Couldn't create thread");
+
+ ASSERT_EQ(migrate_phys(paddr, self->n1, self->n2), 0);
+ for (i = 0; i < self->nthreads - 1; i++)
+ ASSERT_EQ(pthread_cancel(self->threads[i]), 0);
+}
+
TEST_HARNESS_MAIN
--
2.39.1
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