Re: [LTP] [PATCH v8 1/2] cpuset02: Convert the test6 from cpuset_memory_testset.sh to C code

[Petr Vorel <pvorel@suse.cz>]

Hi Li

> Hi Wei,

> Geneally looks good, but some tiny places need improvement.
> See comments inline.

Thanks for the review!

> On Fri, Mar 28, 2025 at 4:00 PM Wei Gao <wegao@suse.com> wrote:

> > Signed-off-by: Wei Gao <wegao@suse.com>
> > Reviewed-by: Petr Vorel <pvorel@suse.cz>
> > Suggested-by: Li Wang <liwang@redhat.com>
> > ---
> >  lib/tst_cgroup.c                       |   1 +
> >  runtest/mm                             |   1 +
> >  testcases/kernel/mem/.gitignore        |   1 +
> >  testcases/kernel/mem/cpuset/Makefile   |   5 +
> >  testcases/kernel/mem/cpuset/cpuset02.c | 138 +++++++++++++++++++++++++
> >  5 files changed, 146 insertions(+)
> >  create mode 100644 testcases/kernel/mem/cpuset/cpuset02.c

> > diff --git a/lib/tst_cgroup.c b/lib/tst_cgroup.c
> > index 73b696c58..545c779e7 100644
> > --- a/lib/tst_cgroup.c
> > +++ b/lib/tst_cgroup.c
> > @@ -204,6 +204,7 @@ static const struct cgroup_file cpuset_ctrl_files[] = {
> >         { "cpuset.cpus", "cpuset.cpus", CTRL_CPUSET },
> >         { "cpuset.mems", "cpuset.mems", CTRL_CPUSET },
> >         { "cpuset.memory_migrate", "cpuset.memory_migrate", CTRL_CPUSET },
> > +       { "cpuset.sched_load_balance", "cpuset.sched_load_balance",
> > CTRL_CPUSET },


> cpuset.sched_load_balance is useful to enable/disable the scheduler can move
> tasks between CPUs in the cpuset.

> Is there any purpose to add this knob in cpuset02 patch? I didn't see you
> touch it in the test.

Wei might had a different reason, but I see all functions in
cpuset_memory_testset.sh (including test6 being rewritten to this test) call
cpuset_funcs.sh which does 'echo 0 > .../cpuset.sched_load_balance', see:

test6()
{
	...
	cpuset_set "$CPUSET/0" "$cpu_of_node0" "0" "0" 2> $CPUSET_TMP/stderr

cpuset_set()
{
	...
	local load_balance="$4"
	...
	/bin/echo $load_balance > $path/cpuset.sched_load_balance

I wonder whether it's good or not.

Kind regards,
Petr

>         { }
> >  };

> > diff --git a/runtest/mm b/runtest/mm
> > index d8e62af81..5af29b0ea 100644
> > --- a/runtest/mm
> > +++ b/runtest/mm
> > @@ -75,6 +75,7 @@ ksm06_2 ksm06 -n 8000
> >  ksm07 ksm07

> >  cpuset01 cpuset01
> > +cpuset02 cpuset02

> >  oom01 oom01
> >  oom02 oom02
> > diff --git a/testcases/kernel/mem/.gitignore
> > b/testcases/kernel/mem/.gitignore
> > index 699e022fb..e24e96001 100644
> > --- a/testcases/kernel/mem/.gitignore
> > +++ b/testcases/kernel/mem/.gitignore
> > @@ -1,4 +1,5 @@
> >  /cpuset/cpuset01
> > +/cpuset/cpuset02
> >  /hugetlb/hugefallocate/hugefallocate01
> >  /hugetlb/hugefallocate/hugefallocate02
> >  /hugetlb/hugefork/hugefork01
> > diff --git a/testcases/kernel/mem/cpuset/Makefile
> > b/testcases/kernel/mem/cpuset/Makefile
> > index bac13e02b..7010c7be4 100644
> > --- a/testcases/kernel/mem/cpuset/Makefile
> > +++ b/testcases/kernel/mem/cpuset/Makefile
> > @@ -19,6 +19,11 @@

> >  top_srcdir             ?= ../../../..

> > +LTPLIBS = numa
> > +
> >  include $(top_srcdir)/include/mk/testcases.mk
> >  include $(top_srcdir)/testcases/kernel/include/lib.mk
> > +
> > +cpuset02: LTPLDLIBS = -lltpnuma
> > +
> >  include $(top_srcdir)/include/mk/generic_leaf_target.mk
> > diff --git a/testcases/kernel/mem/cpuset/cpuset02.c
> > b/testcases/kernel/mem/cpuset/cpuset02.c
> > new file mode 100644
> > index 000000000..26b77f8be
> > --- /dev/null
> > +++ b/testcases/kernel/mem/cpuset/cpuset02.c
> > @@ -0,0 +1,138 @@
> > +// SPDX-License-Identifier: LGPL-2.1-or-later
> > +/*
> > + * Copyright (c) 2025 SUSE LLC <wegao@suse.com>
> > + */
> > +
> > +/*\
> > + * Test checks cpuset.mems works with hugepage file.
> > + * Based on test6 from cpuset_memory_testset.sh written by Miao Xie.
> > + */
> > +
> > +#define _GNU_SOURCE
> > +#include <stdio.h>
> > +#include <sys/mount.h>
> > +#include <limits.h>
> > +#include <sys/param.h>
> > +#include <sys/types.h>
> > +#include "tst_test.h"
> > +
> > +#ifdef HAVE_NUMA_V2
> > +#include <numaif.h>
> > +#include "tst_numa.h"
> > +
> > +#define MNTPOINT "hugetlbfs/"
> > +#define HUGE_PAGE_FILE MNTPOINT "hugepagefile"
> > +
> > +static long hpage_size;
> > +static struct tst_nodemap *node;
> > +static int check_node_id;
> > +static struct tst_cg_group *cg_cpuset_0;
> > +
> > +static void touch_memory_and_check_node(char *p, int size)
> > +{
> > +       int i;
> > +       int node = -1;
> > +       long ret;
> > +       int pagesize = sysconf(_SC_PAGESIZE);
> > +
> > +       for (i = 0; i < size; i += pagesize)
> > +               p[i] = 0xef;
> > +
> > +       ret = get_mempolicy(&node, NULL, 0, p, MPOL_F_NODE | MPOL_F_ADDR);
> > +       if (ret < 0)
> > +               tst_brk(TBROK | TERRNO, "get_mempolicy() failed");
> > +
> > +       if (node == check_node_id)
> > +               tst_res(TPASS, "check node pass");


> I suggest printing the node for detailed info.
>     tst_res(TPASS, "1 huge page allocated on node-%d as expected", node);


> > +       else
> > +               tst_res(TFAIL, "check node failed");


>     tst_res(TFAIL, "1 huge page allocated on node-%d unexpected", node);



> > +}
> > +
> > +static void child(void)
> > +{
> > +       char *p;
> > +       int fd_hugepage;
> > +
> > +       fd_hugepage = SAFE_OPEN(HUGE_PAGE_FILE, O_CREAT | O_RDWR, 0755);
> > +       p = SAFE_MMAP(NULL, hpage_size, PROT_WRITE | PROT_READ,
> > +                               MAP_SHARED, fd_hugepage, 0);
> > +
> > +       touch_memory_and_check_node(p, hpage_size);
> > +
> > +       SAFE_MUNMAP(p, hpage_size);
> > +       SAFE_CLOSE(fd_hugepage);
> > +}
> > +
> > +static void run_test(void)
> > +{
> > +       int pid;
> > +       char node_id_str[256];
> > +
> > +       cg_cpuset_0 = tst_cg_group_mk(tst_cg, "0");
> > +
> > +       sprintf(node_id_str, "%u", check_node_id);
> > +       SAFE_CG_PRINT(cg_cpuset_0, "cpuset.mems", node_id_str);
> > +
> > +       pid = SAFE_FORK();
> > +
> > +       if (!pid) {
> > +               SAFE_CG_PRINTF(cg_cpuset_0, "cgroup.procs", "%d", pid);
> > +               child();
> > +               return;
> > +       }
> > +
> > +       SAFE_WAITPID(pid, NULL, 0);
> > +
> > +       cg_cpuset_0 = tst_cg_group_rm(cg_cpuset_0);
> > +}
> > +
> > +static void setup(void)
> > +{
> > +       node = tst_get_nodemap(TST_NUMA_MEM, getpagesize() / 1024);
> > +       if (node->cnt <= 1)
> > +               tst_brk(TCONF, "test requires at least 2 NUMA memory
> > nodes");
> > +
> > +       check_node_id = node->map[node->cnt - 1];
> > +
> > +       hpage_size = SAFE_READ_MEMINFO(MEMINFO_HPAGE_SIZE)*1024;
> > +
> > +       char path[256];
> > +       unsigned int i;
> > +
> > +       for (i = 0; i < node->cnt; i++) {
> > +               unsigned int current_node_id = node->map[i];
> > +
> > +               sprintf(path,
> > +
> >  "/sys/devices/system/node/node%d/hugepages/hugepages-%ldkB/nr_hugepages",
> > +                       current_node_id, hpage_size / 1024);
> > +               SAFE_FILE_PRINTF(path, "%d", 1);


> SAFE_ macro will break if fails to set the value. However, the reservation
> may not
> succeed here due to memory fragmentation. So we can just use FILE_PRINTF().

> Then, we need an additional check for the target node, if unable to
> reserve, then TCONF there.

I suppose we cannot do the reservation via struct tst_test, right? (using
e.g. TST_SR_SKIP_RO from include/tst_sys_conf.h). That would require at least to
add tst_get_nodemap() to struct tst_test, right?

> > +       }
> > +}
> > +
> > +static void cleanup(void)
> > +{
> > +       if (cg_cpuset_0)
> > +               cg_cpuset_0 = tst_cg_group_rm(cg_cpuset_0);
> > +}
> > +
> > +static struct tst_test test = {
> > +       .needs_root = 1,



> > +       .runs_script = 1,


> Can we remove this line?

+1, definitely not needed here (we don't use shell loader).


> > +       .mntpoint = MNTPOINT,
> > +       .needs_hugetlbfs = 1,
> > +       .setup = setup,
> > +       .forks_child = 1,
> > +       .cleanup = cleanup,
> > +       .test_all = run_test,



> > +       .needs_checkpoints = 1,


> Remove this line?

+1, Cyril asked for removing checkpoints, this is left.

https://lore.kernel.org/ltp/Z88Ymlng3tEOKi0P@yuki.lan/

> > +       .needs_cgroup_ver = TST_CG_V1,


> The test is also useful to CG_V2, so let's remove this line as well.

+1. The original shell script required v1. But C API allows to use both.

Kind regards,
Petr

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