[PATCH 05/30] staging: lustre: remove conditional compilation from libcfs_cpu.c

From: NeilBrown
Date: Sun May 20 2018 - 23:42:55 EST


libcfs_cpu.c manages CPU partitions. In the !CONFIG_SMP case, most
of this disappears and 'static inline's from libcfs_cpu.h are used.
However we still allocate a 'struct cfs_cpt_table' and keep some
dummy data in it. This is a bit pointless.

This patch removes all the !CONFIG_SMP code from libcfs_cpu.c and
conditionally compiles the whole file only when CONFIG_SMP.
We no longer allocate a 'struct cfs_cpt_table' on !CONFIG_SMP,
and don't even declare a structure. The name "cfs_cpt_tab"
becomes always "NULL", which allows some code to be optimized away.

This means that cfs_cpt_tab can sometimes be NULL, so we need to
discard the assertion that it isn't.

Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
.../lustre/include/linux/libcfs/libcfs_cpu.h | 35 ++++++-----
drivers/staging/lustre/lnet/libcfs/Makefile | 2 -
drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c | 62 --------------------
drivers/staging/lustre/lnet/libcfs/module.c | 2 -
4 files changed, 20 insertions(+), 81 deletions(-)

diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs_cpu.h b/drivers/staging/lustre/include/linux/libcfs/libcfs_cpu.h
index 552e9f5c277e..61641c41c492 100644
--- a/drivers/staging/lustre/include/linux/libcfs/libcfs_cpu.h
+++ b/drivers/staging/lustre/include/linux/libcfs/libcfs_cpu.h
@@ -109,6 +109,8 @@ struct cfs_cpt_table {
nodemask_t *ctb_nodemask;
};

+extern struct cfs_cpt_table *cfs_cpt_tab;
+
/**
* return cpumask of CPU partition \a cpt
*/
@@ -202,17 +204,12 @@ int cfs_cpt_spread_node(struct cfs_cpt_table *cptab, int cpt);
*/
int cfs_cpu_ht_nsiblings(int cpu);

+int cfs_cpu_init(void);
+void cfs_cpu_fini(void);
+
#else /* !CONFIG_SMP */
-struct cfs_cpt_table {
- /* # of CPU partitions */
- int ctb_nparts;
- /* cpu mask */
- cpumask_t ctb_mask;
- /* node mask */
- nodemask_t ctb_nodemask;
- /* version */
- u64 ctb_version;
-};
+struct cfs_cpt_table;
+#define cfs_cpt_tab ((struct cfs_cpt_table *)NULL)

static inline cpumask_var_t *
cfs_cpt_cpumask(struct cfs_cpt_table *cptab, int cpt)
@@ -246,7 +243,7 @@ cfs_cpt_online(struct cfs_cpt_table *cptab, int cpt)
static inline nodemask_t *
cfs_cpt_nodemask(struct cfs_cpt_table *cptab, int cpt)
{
- return &cptab->ctb_nodemask;
+ return NULL;
}

static inline int
@@ -327,9 +324,18 @@ cfs_cpt_bind(struct cfs_cpt_table *cptab, int cpt)
{
return 0;
}
-#endif /* CONFIG_SMP */

-extern struct cfs_cpt_table *cfs_cpt_tab;
+static inline int
+cfs_cpu_init(void)
+{
+ return 0;
+}
+
+static inline void cfs_cpu_fini(void)
+{
+}
+
+#endif /* CONFIG_SMP */

/**
* destroy a CPU partition table
@@ -425,7 +431,4 @@ void cfs_percpt_unlock(struct cfs_percpt_lock *pcl, int index);
#define cfs_cpt_for_each(i, cptab) \
for (i = 0; i < cfs_cpt_number(cptab); i++)

-int cfs_cpu_init(void);
-void cfs_cpu_fini(void);
-
#endif /* __LIBCFS_CPU_H__ */
diff --git a/drivers/staging/lustre/lnet/libcfs/Makefile b/drivers/staging/lustre/lnet/libcfs/Makefile
index 6335f909d22b..6a1b232da495 100644
--- a/drivers/staging/lustre/lnet/libcfs/Makefile
+++ b/drivers/staging/lustre/lnet/libcfs/Makefile
@@ -10,7 +10,7 @@ libcfs-obj-y += linux-crypto-adler.o

libcfs-obj-y += debug.o fail.o module.o tracefile.o
libcfs-obj-y += libcfs_string.o hash.o
-libcfs-obj-y += libcfs_cpu.o
+libcfs-obj-$(CONFIG_SMP) += libcfs_cpu.o
libcfs-obj-y += libcfs_mem.o libcfs_lock.o

libcfs-objs := $(libcfs-obj-y)
diff --git a/drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c b/drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c
index 2133ffec49a9..40509b2acfb3 100644
--- a/drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c
+++ b/drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c
@@ -42,7 +42,6 @@ EXPORT_SYMBOL(cfs_cpt_tab);
#include <linux/sched.h>
#include <linux/libcfs/libcfs.h>

-#ifdef CONFIG_SMP
/**
* modparam for setting number of partitions
*
@@ -81,11 +80,9 @@ static struct cfs_cpt_data {
/* scratch buffer for set/unset_node */
cpumask_var_t cpt_cpumask;
} cpt_data;
-#endif

#define CFS_CPU_VERSION_MAGIC 0xbabecafe

-#ifdef CONFIG_SMP
struct cfs_cpt_table *
cfs_cpt_table_alloc(unsigned int ncpt)
{
@@ -139,30 +136,8 @@ cfs_cpt_table_alloc(unsigned int ncpt)
cfs_cpt_table_free(cptab);
return NULL;
}
-#else /* ! CONFIG_SMP */
-struct cfs_cpt_table *
-cfs_cpt_table_alloc(unsigned int ncpt)
-{
- struct cfs_cpt_table *cptab;
-
- if (ncpt != 1) {
- CERROR("Can't support cpu partition number %d\n", ncpt);
- return NULL;
- }
-
- cptab = kzalloc(sizeof(*cptab), GFP_NOFS);
- if (cptab) {
- cptab->ctb_version = CFS_CPU_VERSION_MAGIC;
- node_set(0, cptab->ctb_nodemask);
- cptab->ctb_nparts = ncpt;
- }
-
- return cptab;
-}
-#endif /* CONFIG_SMP */
EXPORT_SYMBOL(cfs_cpt_table_alloc);

-#ifdef CONFIG_SMP
void
cfs_cpt_table_free(struct cfs_cpt_table *cptab)
{
@@ -184,18 +159,8 @@ cfs_cpt_table_free(struct cfs_cpt_table *cptab)

kfree(cptab);
}
-#else /* ! CONFIG_SMP */
-void
-cfs_cpt_table_free(struct cfs_cpt_table *cptab)
-{
- LASSERT(cptab->ctb_version == CFS_CPU_VERSION_MAGIC);
-
- kfree(cptab);
-}
-#endif /* CONFIG_SMP */
EXPORT_SYMBOL(cfs_cpt_table_free);

-#ifdef CONFIG_SMP
int
cfs_cpt_table_print(struct cfs_cpt_table *cptab, char *buf, int len)
{
@@ -238,9 +203,7 @@ cfs_cpt_table_print(struct cfs_cpt_table *cptab, char *buf, int len)
return tmp - buf;
}
EXPORT_SYMBOL(cfs_cpt_table_print);
-#endif /* CONFIG_SMP */

-#ifdef CONFIG_SMP
static void
cfs_node_to_cpumask(int node, cpumask_t *mask)
{
@@ -624,10 +587,6 @@ cfs_cpt_bind(struct cfs_cpt_table *cptab, int cpt)
}
EXPORT_SYMBOL(cfs_cpt_bind);

-#endif
-
-#ifdef CONFIG_SMP
-
/**
* Choose max to \a number CPUs from \a node and set them in \a cpt.
* We always prefer to choose CPU in the same core/socket.
@@ -1122,24 +1081,3 @@ cfs_cpu_init(void)
cfs_cpu_fini();
return ret;
}
-
-#else /* ! CONFIG_SMP */
-
-void
-cfs_cpu_fini(void)
-{
- if (cfs_cpt_tab) {
- cfs_cpt_table_free(cfs_cpt_tab);
- cfs_cpt_tab = NULL;
- }
-}
-
-int
-cfs_cpu_init(void)
-{
- cfs_cpt_tab = cfs_cpt_table_alloc(1);
-
- return cfs_cpt_tab ? 0 : -1;
-}
-
-#endif /* CONFIG_SMP */
diff --git a/drivers/staging/lustre/lnet/libcfs/module.c b/drivers/staging/lustre/lnet/libcfs/module.c
index 6d1c1ad63e16..3e51aae751c5 100644
--- a/drivers/staging/lustre/lnet/libcfs/module.c
+++ b/drivers/staging/lustre/lnet/libcfs/module.c
@@ -461,8 +461,6 @@ static int __proc_cpt_table(void *data, int write,
if (write)
return -EPERM;

- LASSERT(cfs_cpt_tab);
-
while (1) {
buf = kzalloc(len, GFP_KERNEL);
if (!buf)