[PATCH 2/3] staging: lustre: lnet: Allocate MEs and small MDs in own kmem_caches

James Simmons
2016-06-09T22:46:56Z

From: Bruno Faccini <bruno.faccini@intel.com>

As part of LU-3848 and LU-4330, it has been discovered that LNET
MEs and small MDs (<=128 Bytes) are allocated in <size-128> kmem_cache
and thus can suffer quite frequent corruptions, from other modules or
Kernel parts, that occur there. To avoid this, MEs and small-MDs
specific kmem_cache have been created.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4430
Reviewed-on: http://review.whamcloud.com/18586
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
---
.../staging/lustre/include/linux/lnet/lib-lnet.h | 36 ++++++++++++++--
drivers/staging/lustre/lnet/lnet/api-ni.c | 45 ++++++++++++++++++++
2 files changed, 77 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/lustre/include/linux/lnet/lib-lnet.h b/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
index 513a822..51ad729 100644
--- a/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
+++ b/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
@@ -178,6 +178,11 @@ lnet_net_lock_current(void)

#define MAX_PORTALS 64

+#define LNET_SMALL_MD_SIZE offsetof(lnet_libmd_t, md_iov.iov[1])
+extern struct kmem_cache *lnet_mes_cachep; /* MEs kmem_cache */
+extern struct kmem_cache *lnet_small_mds_cachep;/* <= LNET_SMALL_MD_SIZE bytes
+ * MDs kmem_cache
+ */
static inline lnet_eq_t *
lnet_eq_alloc(void)
{
@@ -208,7 +213,19 @@ lnet_md_alloc(lnet_md_t *umd)
size = offsetof(lnet_libmd_t, md_iov.iov[niov]);
}

- LIBCFS_ALLOC(md, size);
+ if (size <= LNET_SMALL_MD_SIZE) {
+ md = kmem_cache_alloc(lnet_small_mds_cachep,
+ GFP_NOFS | __GFP_ZERO);
+ if (md) {
+ CDEBUG(D_MALLOC, "slab-alloced 'md' of size %u at %p.\n",
+ size, md);
+ } else {
+ CDEBUG(D_MALLOC, "failed to allocate 'md' of size %u\n",
+ size);
+ }
+ } else {
+ LIBCFS_ALLOC(md, size);
+ }

if (md) {
/* Set here in case of early free */
@@ -230,7 +247,12 @@ lnet_md_free(lnet_libmd_t *md)
else
size = offsetof(lnet_libmd_t, md_iov.iov[md->md_niov]);

- LIBCFS_FREE(md, size);
+ if (size <= LNET_SMALL_MD_SIZE) {
+ CDEBUG(D_MALLOC, "slab-freed 'md' at %p.\n", md);
+ kmem_cache_free(lnet_small_mds_cachep, md);
+ } else {
+ LIBCFS_FREE(md, size);
+ }
}

static inline lnet_me_t *
@@ -238,14 +260,20 @@ lnet_me_alloc(void)
{
lnet_me_t *me;

- LIBCFS_ALLOC(me, sizeof(*me));
+ me = kmem_cache_alloc(lnet_mes_cachep, GFP_NOFS | __GFP_ZERO);
+ if (me)
+ CDEBUG(D_MALLOC, "slab-alloced 'me' at %p.\n", me);
+ else
+ CDEBUG(D_MALLOC, "failed to allocate 'me'\n");
+
return me;
}

static inline void
lnet_me_free(lnet_me_t *me)
{
- LIBCFS_FREE(me, sizeof(*me));
+ CDEBUG(D_MALLOC, "slab-freed 'me' at %p.\n", me);
+ kmem_cache_free(lnet_mes_cachep, me);
}

static inline lnet_msg_t *
diff --git a/drivers/staging/lustre/lnet/lnet/api-ni.c b/drivers/staging/lustre/lnet/lnet/api-ni.c
index fe0dbe7..9db0ff1 100644
--- a/drivers/staging/lustre/lnet/lnet/api-ni.c
+++ b/drivers/staging/lustre/lnet/lnet/api-ni.c
@@ -103,6 +103,46 @@ lnet_init_locks(void)
mutex_init(&the_lnet.ln_api_mutex);
}

+struct kmem_cache *lnet_mes_cachep; /* MEs kmem_cache */
+struct kmem_cache *lnet_small_mds_cachep; /* <= LNET_SMALL_MD_SIZE bytes
+ * MDs kmem_cache
+ */
+static int
+lnet_descriptor_setup(void)
+{
+ /*
+ * create specific kmem_cache for MEs and small MDs (i.e., originally
+ * allocated in <size-xxx> kmem_cache).
+ */
+ lnet_mes_cachep = kmem_cache_create("lnet_MEs", sizeof(lnet_me_t),
+ 0, 0, NULL);
+ if (!lnet_mes_cachep)
+ return -ENOMEM;
+
+ lnet_small_mds_cachep = kmem_cache_create("lnet_small_MDs",
+ LNET_SMALL_MD_SIZE, 0, 0,
+ NULL);
+ if (!lnet_small_mds_cachep)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void
+lnet_descriptor_cleanup(void)
+{
+
+ if (lnet_small_mds_cachep) {
+ kmem_cache_destroy(lnet_small_mds_cachep);
+ lnet_small_mds_cachep = NULL;
+ }
+
+ if (lnet_mes_cachep) {
+ kmem_cache_destroy(lnet_mes_cachep);
+ lnet_mes_cachep = NULL;
+ }
+}
+
static int
lnet_create_remote_nets_table(void)
{
@@ -553,6 +593,10 @@ lnet_prepare(lnet_pid_t requested_pid)
INIT_LIST_HEAD(&the_lnet.ln_drop_rules);
INIT_LIST_HEAD(&the_lnet.ln_delay_rules);

+ rc = lnet_descriptor_setup();
+ if (rc)
+ goto failed;
+
rc = lnet_create_remote_nets_table();
if (rc)
goto failed;
@@ -652,6 +696,7 @@ lnet_unprepare(void)
the_lnet.ln_counters = NULL;
}
lnet_destroy_remote_nets_table();
+ lnet_descriptor_cleanup();

return 0;
}
--
1.7.1