mm/swapping01: new testcase
swapping01 - first time swap use results in heavy swapping
This case is used for testing upstream commit: 50a1598.
The upstream commit fixed a issue on s390/x platform that heavy
swapping might occur in some condition, however since the patch
was quite general, this testcase will be run on all supported
platforms to ensure no regression been introduced.
Details of the upstream fix:
On x86 a page without a mapper is by definition not referenced / old.
The s390 architecture keeps the reference bit in the storage key and
the current code will check the storage key for page without a mapper.
This leads to an interesting effect: the first time an s390 system
needs to write pages to swap it only finds referenced pages. This
causes a lot of pages to get added and written to the swap device.
To avoid this behaviour change page_referenced to query the storage
key only if there is a mapper of the page.
Test Strategy:
Try to allocate memory which size is slightly larger than current
available memory. After allocation done, continue loop for a while
and calculate the used swap size. The used swap size should be small
enough, else it indicates that heavy swapping is occured unexpectedly.
Signed-off-by: Caspar Zhang <caspar@casparzhang.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
diff --git a/runtest/mm b/runtest/mm
index 245e50d..be3b342 100644
--- a/runtest/mm
+++ b/runtest/mm
@@ -78,6 +78,8 @@
oom03 oom03
oom04 oom04
+swapping01 swapping01 -i 5
+
thp01 thp01 -I 120
thp02 thp02
diff --git a/testcases/kernel/mem/swapping/Makefile b/testcases/kernel/mem/swapping/Makefile
new file mode 100644
index 0000000..0baac98
--- /dev/null
+++ b/testcases/kernel/mem/swapping/Makefile
@@ -0,0 +1,43 @@
+#
+# Copyright (C) 2012 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or (at
+# your option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
+#
+
+top_srcdir ?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+
+LDLIBS += $(NUMA_LIBS) -lmem -lltp
+LIBDIR := ../lib
+LIB := $(LIBDIR)/libmem.a
+FILTER_OUT_DIRS := $(LIBDIR)
+LDFLAGS += -L$(LIBDIR)
+
+$(LIBDIR):
+ mkdir -p "$@"
+
+$(LIB): $(LIBDIR)
+ $(MAKE) -C $^ -f "$(abs_srcdir)/$^/Makefile" all
+
+MAKE_DEPS := $(LIB)
+
+trunk-clean:: | lib-clean
+
+lib-clean:: $(LIBDIR)
+ $(MAKE) -C $^ -f "$(abs_srcdir)/$^/Makefile" clean
+
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/mem/swapping/swapping01.c b/testcases/kernel/mem/swapping/swapping01.c
new file mode 100644
index 0000000..8b53e17
--- /dev/null
+++ b/testcases/kernel/mem/swapping/swapping01.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Further, this software is distributed without any warranty that it
+ * is free of the rightful claim of any third person regarding
+ * infringement or the like. Any license provided herein, whether
+ * implied or otherwise, applies only to this software file. Patent
+ * licenses, if any, provided herein do not apply to combinations of
+ * this program with other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+/*
+ * swapping01 - first time swap use results in heavy swapping
+ *
+ * This case is used for testing upstream commit: 50a1598
+ *
+ * The upstream commit fixed a issue on s390/x platform that heavy
+ * swapping might occur in some condition, however since the patch
+ * was quite general, this testcase will be run on all supported
+ * platforms to ensure no regression been introduced.
+ *
+ * Details of the upstream fix:
+ * On x86 a page without a mapper is by definition not referenced / old.
+ * The s390 architecture keeps the reference bit in the storage key and
+ * the current code will check the storage key for page without a mapper.
+ * This leads to an interesting effect: the first time an s390 system
+ * needs to write pages to swap it only finds referenced pages. This
+ * causes a lot of pages to get added and written to the swap device.
+ * To avoid this behaviour change page_referenced to query the storage
+ * key only if there is a mapper of the page.
+ *
+ * Test Strategy:
+ * Try to allocate memory which size is slightly larger than current
+ * available memory. After allocation done, continue loop for a while
+ * and calculate the used swap size. The used swap size should be small
+ * enough, else it indicates that heavy swapping is occured unexpectedly.
+ */
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "test.h"
+#include "usctest.h"
+#include "../include/mem.h"
+
+char *TCID = "swapping01";
+int TST_TOTAL = 1;
+
+/* allow swapping 0.5 * phy_mem in maximum */
+#define COE_DELTA 0.5
+/* will try to alloc 1.3 * phy_mem */
+#define COE_SLIGHT_OVER 0.3
+
+static void init_meminfo(void);
+static void do_alloc(void);
+static void check_swapping(void);
+
+static long mem_free_init;
+static long swap_free_init;
+static long mem_over;
+static long mem_over_max;
+static pid_t pid;
+
+int main(int argc, char *argv[])
+{
+ int lc;
+ char *msg;
+
+ msg = parse_opts(argc, argv, NULL, NULL);
+ if (msg != NULL)
+ tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg);
+
+#if __WORDSIZE == 32
+ tst_brkm(TCONF, NULL, "test is not designed for 32-bit system.");
+#endif
+
+ setup();
+
+ for (lc = 0; TEST_LOOPING(lc); lc++) {
+ Tst_count = 0;
+
+ init_meminfo();
+
+ switch (pid = fork()) {
+ case -1:
+ tst_brkm(TBROK|TERRNO, cleanup, "fork");
+ case 0:
+ do_alloc();
+ exit(0);
+ default:
+ check_swapping();
+ }
+ }
+ cleanup();
+ tst_exit();
+}
+
+static void init_meminfo(void)
+{
+ swap_free_init = read_meminfo("SwapFree:");
+ mem_free_init = read_meminfo("MemFree:");
+ mem_over = mem_free_init * COE_SLIGHT_OVER;
+ mem_over_max = mem_free_init * COE_DELTA;
+
+ /* at least 10MB free physical memory needed */
+ if (mem_free_init < 10240) {
+ sleep(5);
+ if (mem_free_init < 10240)
+ tst_brkm(TCONF, cleanup,
+ "Not enough free memory to test.");
+ }
+ if (swap_free_init < mem_over)
+ tst_brkm(TCONF, cleanup, "Not enough swap space to test.");
+}
+
+static void do_alloc(void)
+{
+ long mem_count;
+ void *s;
+
+ tst_resm(TINFO, "free physical memory: %ld MB", mem_free_init / 1024);
+ mem_count = mem_free_init + mem_over;
+ tst_resm(TINFO, "try to allocate: %ld MB", mem_count / 1024);
+ s = malloc(mem_count * 1024);
+ if (s == NULL)
+ tst_brkm(TBROK|TERRNO, cleanup, "malloc");
+ memset(s, 1, mem_count * 1024);
+ tst_resm(TINFO, "memory allocated: %ld MB", mem_count / 1024);
+ if (raise(SIGSTOP) == -1)
+ tst_brkm(TBROK|TERRNO, tst_exit, "kill");
+ free(s);
+}
+
+static void check_swapping(void)
+{
+ int status, i;
+ long swapped;
+
+ /* wait child stop */
+ if (waitpid(pid, &status, WUNTRACED) == -1)
+ tst_brkm(TBROK|TERRNO, cleanup, "waitpid");
+ if (!WIFSTOPPED(status))
+ tst_brkm(TBROK, cleanup, "child was not stopped.");
+
+ /* Still occupying memory, loop for a while */
+ for (i = 0; i < 10; i++) {
+ swapped = swap_free_init - read_meminfo("SwapFree:");
+ if (swapped > mem_over_max) {
+ kill(pid, SIGCONT);
+ tst_brkm(TFAIL, cleanup, "heavy swapping detected: "
+ "%ld MB swapped.", swapped / 1024);
+ }
+ sleep(1);
+ }
+ tst_resm(TPASS, "no heavy swapping detected, %ld MB swapped.",
+ swapped / 1024);
+ kill(pid, SIGCONT);
+ /* wait child exit */
+ if (waitpid(pid, &status, 0) == -1)
+ tst_brkm(TBROK|TERRNO, cleanup, "waitpid");
+}
+
+void setup(void)
+{
+ tst_sig(FORK, DEF_HANDLER, cleanup);
+
+ TEST_PAUSE;
+}
+
+void cleanup(void)
+{
+ TEST_CLEANUP;
+}