From bd170e63ba57d81c5ef721d7a5816df49228c9ae Mon Sep 17 00:00:00 2001
From: Balazs Gerofi <bgerofi@riken.jp>
Date: Wed, 23 Aug 2017 10:17:14 +0900
Subject: [PATCH] kmalloc cache refactor and pre-alloc in HFI1 open()

---
 kernel/mem.c       | 36 ++++++++++++++++++++++--------------
 kernel/syscall.c   |  3 +++
 kernel/user_sdma.c |  6 ++++++
 3 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/kernel/mem.c b/kernel/mem.c
index 5d987f08..f8373fb7 100644
--- a/kernel/mem.c
+++ b/kernel/mem.c
@@ -2615,6 +2615,27 @@ int ihk_mc_get_mem_user_page(void *arg0, page_table_t pt, pte_t *ptep, void *pga
 /*
  * Generic lockless kmalloc cache.
  */
+void kmalloc_cache_prealloc(struct kmalloc_cache_header *cache,
+		size_t size)
+{
+	struct kmalloc_cache_header *first;
+	int i;
+	kprintf("%s: pre-allocating for 0x%lx...\n",
+			__FUNCTION__, cache);
+
+	for (i = 0; i < 128; ++i) {
+		first = (struct kmalloc_cache_header *)
+			kmalloc(size, IHK_MC_AP_NOWAIT);
+
+		if (!first) {
+			kprintf("%s: ERROR: allocating cache element\n", __FUNCTION__);
+			continue;
+		}
+
+		kmalloc_cache_free(cache, first);
+	}
+}
+
 void *kmalloc_cache_alloc(struct kmalloc_cache_header *cache,
 		size_t size)
 {
@@ -2633,20 +2654,7 @@ retry:
 		}
 	}
 	else {
-		int i;
-		kprintf("%s: cache empty, allocating ...\n", __FUNCTION__);
-		for (i = 0; i < 100; ++i) {
-			first = (struct kmalloc_cache_header *)
-				kmalloc(size, IHK_MC_AP_NOWAIT);
-
-			if (!first) {
-				kprintf("%s: ERROR: allocating cache element\n", __FUNCTION__);
-				continue;
-			}
-
-			kmalloc_cache_free(cache, first);
-		}
-
+		kmalloc_cache_prealloc(cache, size);
 		goto retry;
 	}
 
diff --git a/kernel/syscall.c b/kernel/syscall.c
index b2878d83..b353d2b2 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -483,11 +483,14 @@ long do_syscall(struct syscall_request *req, int cpu, int pid)
 	if (req->number == __NR_open && rc > 0) {
 		if (res.private_data &&
 				!strncmp((const char *)req->args[0], "/dev/hfi", 8)) {
+			extern void hfi1_txreq_prealloc(void);
+
 			thread->proc->fd_priv_table[rc] = res.private_data;
 			kprintf("%s: PID: %d, open fd: %d, filename: "
 					"%s, private_data: 0x%lx\n",
 					__FUNCTION__, thread->proc->pid,
 					rc, req->args[0], res.private_data);
+			hfi1_txreq_prealloc();
 		}
 	}
 
diff --git a/kernel/user_sdma.c b/kernel/user_sdma.c
index b8baee0c..263ba538 100644
--- a/kernel/user_sdma.c
+++ b/kernel/user_sdma.c
@@ -1216,6 +1216,12 @@ static inline u32 get_lrh_len(struct hfi1_pkt_header hdr, u32 len)
 
 struct kmalloc_cache_header txreq_cache = {NULL};
 
+
+void hfi1_txreq_prealloc(void)
+{
+	kmalloc_cache_prealloc(&txreq_cache, sizeof(struct user_sdma_txreq));
+}
+
 static int user_sdma_send_pkts(struct user_sdma_request *req, unsigned maxpkts)
 {
 	int ret = 0, count;