[LTP] [PATCH 5/7] mem/ksm06: Move ksm restoration into the tst_test struct

[Cyril Hrubis]

Hi!
> > > But for the two knobs(run, sleep_millisecs) that should exist unless
> > > the kernel disables KSM. So here we'd better start with prefix '!' and
> > > add .needs_kconfg for ???CONFIG_KSM=y' check.
> > > (This also fit for other ksm tests)
> >
> > I guess that if we put ! before the merge_across_nodes that would cause
> > TBROK on systems without CONFIG_NUMA or kernels without that feature.
> >
> > So what about just removing the question marks there and adding
> > .need_kconfigs for KSM and NUMA?
> >
> 
> Er, that's exactly what I meant in the last email, maybe you overlooked
> the last sentence:).
> 
> i.e.
> 
> "
>   prefix ! for 'run' and 'sleep_milisecs'
>   no prefix for 'merge_across_nodes'
>   .need_kconfigs for KSM and NUMA
> "

Ah, right, sorry. What about this:

diff --git a/testcases/kernel/mem/ksm/ksm06.c b/testcases/kernel/mem/ksm/ksm06.c
index 61507b2aa..e734786c1 100644
--- a/testcases/kernel/mem/ksm/ksm06.c
+++ b/testcases/kernel/mem/ksm/ksm06.c
@@ -39,9 +39,6 @@
 #ifdef HAVE_NUMA_V2
 #include <numaif.h>

-static int run = -1;
-static int sleep_millisecs = -1;
-static int merge_across_nodes = -1;
 static unsigned long nr_pages = 100;

 static char *n_opt;
@@ -133,35 +130,11 @@ static void test_ksm(void)

 static void setup(void)
 {
-       if (access(PATH_KSM "merge_across_nodes", F_OK) == -1)
-               tst_brk(TCONF, "no merge_across_nodes sysfs knob");
-
        if (!is_numa(NULL, NH_MEMS, 2))
                tst_brk(TCONF, "The case needs a NUMA system.");

        if (n_opt)
                nr_pages = SAFE_STRTOUL(n_opt, 0, ULONG_MAX);
-
-       /* save the current value */
-       SAFE_FILE_SCANF(PATH_KSM "run", "%d", &run);
-       SAFE_FILE_SCANF(PATH_KSM "merge_across_nodes",
-                       "%d", &merge_across_nodes);
-       SAFE_FILE_SCANF(PATH_KSM "sleep_millisecs",
-                       "%d", &sleep_millisecs);
-}
-
-static void cleanup(void)
-{
-       if (merge_across_nodes != -1) {
-               FILE_PRINTF(PATH_KSM "merge_across_nodes",
-                           "%d", merge_across_nodes);
-       }
-
-       if (sleep_millisecs != -1)
-               FILE_PRINTF(PATH_KSM "sleep_millisecs", "%d", sleep_millisecs);
-
-       if (run != -1)
-               FILE_PRINTF(PATH_KSM "run", "%d", run);
 }
 
 static struct tst_test test = {
@@ -171,11 +144,18 @@ static struct tst_test test = {
                {}
        },
        .setup = setup,
-       .cleanup = cleanup,
        .save_restore = (const char * const[]) {
                "?/sys/kernel/mm/ksm/max_page_sharing",
+               "!/sys/kernel/mm/ksm/run",
+               "!/sys/kernel/mm/ksm/sleep_millisecs",
+               "/sys/kernel/mm/ksm/merge_across_nodes",
                NULL,
        },
+       .needs_kconfigs = (const char *const[]){
+               "CONFIG_KSM=y",
+               "CONFIG_NUMA=y",
+               NULL
+       },
        .test_all = test_ksm,
 };


If we add merge_across_nodes without any prefix we can as well remove
the check for the file existence in the test setup.

-- 
Cyril Hrubis
chrubis@suse.cz