[PATCH v3 1/7] S390: Remove now superfluous sentinel elem from ctl_table arrays

Joel Granados via B4 Relay
2023-10-02T11:29:23Z

empty elements at the end of the ctl_table arrays (sentinels) which will
reduce the overall build time size of the kernel and run time memory
bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove the sentinel element from appldata_table, s390dbf_table,
topology_ctl_table, cmm_table and page_table_sysctl. Reduced the memory
allocation in appldata_register_ops by 1 effectively removing the
sentinel from ops->ctl_table.

This removal is safe because register_sysctl_sz and register_sysctl use
the array size in addition to checking for the sentinel.

Tested-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
---
arch/s390/appldata/appldata_base.c | 4 +---
arch/s390/kernel/debug.c | 1 -
arch/s390/kernel/topology.c | 1 -
arch/s390/mm/cmm.c | 1 -
arch/s390/mm/pgalloc.c | 1 -
5 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/arch/s390/appldata/appldata_base.c b/arch/s390/appldata/appldata_base.c
index 3b0994625652..c2978cb03b36 100644
--- a/arch/s390/appldata/appldata_base.c
+++ b/arch/s390/appldata/appldata_base.c
@@ -63,7 +63,6 @@ static struct ctl_table appldata_table[] = {
.mode = S_IRUGO | S_IWUSR,
.proc_handler = appldata_interval_handler,
},
- { },
};

/*
@@ -351,8 +350,7 @@ int appldata_register_ops(struct appldata_ops *ops)
if (ops->size > APPLDATA_MAX_REC_SIZE)
return -EINVAL;

- /* The last entry must be an empty one */
- ops->ctl_table = kcalloc(2, sizeof(struct ctl_table), GFP_KERNEL);
+ ops->ctl_table = kcalloc(1, sizeof(struct ctl_table), GFP_KERNEL);
if (!ops->ctl_table)
return -ENOMEM;

diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index a85e0c3e7027..85328a0ef3b6 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -978,7 +978,6 @@ static struct ctl_table s390dbf_table[] = {
.mode = S_IRUGO | S_IWUSR,
.proc_handler = s390dbf_procactive,
},
- { }
};

static struct ctl_table_header *s390dbf_sysctl_header;
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 68adf1de8888..be8467b25953 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -636,7 +636,6 @@ static struct ctl_table topology_ctl_table[] = {
.mode = 0644,
.proc_handler = topology_ctl_handler,
},
- { },
};

static int __init topology_init(void)
diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index f47515313226..f8b13f247646 100644
--- a/arch/s390/mm/cmm.c
+++ b/arch/s390/mm/cmm.c
@@ -332,7 +332,6 @@ static struct ctl_table cmm_table[] = {
.mode = 0644,
.proc_handler = cmm_timeout_handler,
},
- { }
};

#ifdef CONFIG_CMM_IUCV
diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 07fc660a24aa..75e1039f2ec5 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -30,7 +30,6 @@ static struct ctl_table page_table_sysctl[] = {
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
- { }
};

static int __init page_table_register_sysctl(void)

--
2.30.2