[dpdk-dev] [PATCH v3] lib/librte_eal/linuxapp: fix runtime config mmap issue

[Li Han]

In rte_eal_config_reattach(),the secondary mmap may fail
due to the rte_mem_cfg_addr already be used by others.do
the change just as the rte_fbarray_init() do.if no
base_virtaddr,use the default 0x100000000.

v2/v3:
-fix code style issues

Signed-off-by: Li Han <han....@zte.com.cn>
---
 lib/librte_eal/linux/eal/eal.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
index f397206..ab0b5a0 100644
--- a/lib/librte_eal/linux/eal/eal.c
+++ b/lib/librte_eal/linux/eal/eal.c
@@ -308,20 +308,32 @@ enum rte_iova_mode
 {
        void *rte_mem_cfg_addr;
        int retval;
+       size_t page_sz, mmap_len;
 
        const char *pathname = eal_runtime_config_path();
 
        if (internal_config.no_shconf)
                return 0;
-
+       mmap_len = sizeof(*rte_config.mem_config);
        /* map the config before hugepage address so that we don't waste a page 
*/
        if (internal_config.base_virtaddr != 0)
                rte_mem_cfg_addr = (void *)
                        RTE_ALIGN_FLOOR(internal_config.base_virtaddr -
                        sizeof(struct rte_mem_config), sysconf(_SC_PAGE_SIZE));
-       else
-               rte_mem_cfg_addr = NULL;
-
+       else {
+               page_sz = sysconf(_SC_PAGESIZE);
+               if (page_sz == (size_t)-1) {
+                       RTE_LOG(ERR, EAL,
+                               "Cannot get SC_PAGESIZE for rte_mem_config\n");
+                       return -1;
+               }
+               rte_mem_cfg_addr = eal_get_virtual_area(NULL, &mmap_len, 
page_sz, 0, 0);
+               if (rte_mem_cfg_addr == NULL) {
+                       RTE_LOG(ERR, EAL,
+                               "Cannot get virtual addr for rte_mem_config\n");
+                       return -1;
+               }
+       }
        if (mem_cfg_fd < 0){
                mem_cfg_fd = open(pathname, O_RDWR | O_CREAT, 0600);
                if (mem_cfg_fd < 0) {
@@ -349,8 +361,10 @@ enum rte_iova_mode
                return -1;
        }
 
-       rte_mem_cfg_addr = mmap(rte_mem_cfg_addr, 
sizeof(*rte_config.mem_config),
-                               PROT_READ | PROT_WRITE, MAP_SHARED, mem_cfg_fd, 
0);
+       rte_mem_cfg_addr = mmap(rte_mem_cfg_addr, mmap_len,
+                               PROT_READ | PROT_WRITE,
+                               MAP_FIXED | MAP_SHARED,
+                               mem_cfg_fd, 0);
 
        if (rte_mem_cfg_addr == MAP_FAILED){
                close(mem_cfg_fd);
-- 
1.8.3.1