[lng-odp] [PATCH v3 2/2] linux-gen: ishm: make huge page cache size dynamic

[Github ODP bot]

From: Josep Puigdemont <josep.puigdem...@linaro.org>

Signed-off-by: Josep Puigdemont <josep.puigdem...@linaro.org>
---
/** Email created from pull request 685 (joseppc:fix/cache_huge_pages)
 ** https://github.com/Linaro/odp/pull/685
 ** Patch: https://github.com/Linaro/odp/pull/685.patch
 ** Base sha: 6d48d7f7f684b8aa87f7eb4f922d45be345ed771
 ** Merge commit sha: 72e8f7c6b712af7da295dbcf41b222e016ee5cc4
 **/
 platform/linux-generic/odp_ishm.c | 73 +++++++++++++++++++------------
 1 file changed, 45 insertions(+), 28 deletions(-)

diff --git a/platform/linux-generic/odp_ishm.c 
b/platform/linux-generic/odp_ishm.c
index b1009355d..dd82c329a 100644
--- a/platform/linux-generic/odp_ishm.c
+++ b/platform/linux-generic/odp_ishm.c
@@ -239,15 +239,15 @@ typedef struct {
 } ishm_ftable_t;
 static ishm_ftable_t *ishm_ftbl;
 
-#define HP_CACHE_SIZE 64
 struct huge_page_cache {
        uint64_t len;
+       int max_fds; /* maximum amount requested of pre-allocated huge pages */
        int total;   /* amount of actually pre-allocated huge pages */
        int idx;     /* retrieve fd[idx] to get a free file descriptor */
-       int fd[HP_CACHE_SIZE]; /* list of file descriptors */
+       int fd[];    /* list of file descriptors */
 };
 
-static struct huge_page_cache hpc;
+static struct huge_page_cache *hpc;
 
 #ifndef MAP_ANONYMOUS
 #define MAP_ANONYMOUS MAP_ANON
@@ -301,19 +301,14 @@ static void hp_init(void)
        char filename[ISHM_FILENAME_MAXLEN];
        char dir[ISHM_FILENAME_MAXLEN];
        int count;
-
-       hpc.total = 0;
-       hpc.idx = -1;
-       hpc.len = odp_sys_huge_page_size();
+       void *addr;
 
        if (!_odp_libconfig_lookup_ext_int("ishm", NULL, "num_reserved_hp",
                                           &count)) {
                return;
        }
 
-       if (count > HP_CACHE_SIZE)
-               count = HP_CACHE_SIZE;
-       else if (count <= 0)
+       if (count <= 0)
                return;
 
        ODP_DBG("Init HP cache with up to %d pages\n", count);
@@ -339,55 +334,77 @@ static void hp_init(void)
                 dir,
                 odp_global_data.main_pid);
 
+       addr = mmap(NULL,
+                   sizeof(struct huge_page_cache) + sizeof(int) * count,
+                   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+       if (addr == MAP_FAILED) {
+               ODP_ERR("Unable to mmap memory for huge page cache\n.");
+               return;
+       }
+
+       hpc = addr;
+
+       hpc->max_fds = count;
+       hpc->total = 0;
+       hpc->idx = -1;
+       hpc->len = odp_sys_huge_page_size();
+
        for (int i = 0; i < count; ++i) {
                int fd;
 
-               fd = hp_create_file(hpc.len, filename);
-               if (fd == -1)
+               fd = hp_create_file(hpc->len, filename);
+               if (fd == -1) {
+                       do {
+                               hpc->fd[i++] = -1;
+                       } while (i < count);
                        break;
-               hpc.total++;
-               hpc.fd[i] = fd;
+               }
+               hpc->total++;
+               hpc->fd[i] = fd;
        }
-       hpc.idx = hpc.total - 1;
+       hpc->idx = hpc->total - 1;
 
        ODP_DBG("HP cache has %d huge pages of size 0x%08" PRIx64 "\n",
-               hpc.total, hpc.len);
+               hpc->total, hpc->len);
 }
 
 static void hp_term(void)
 {
-       for (int i = 0; i < hpc.total; i++) {
-               if (hpc.fd[i] != -1)
-                       close(hpc.fd[i]);
+       if (NULL == hpc)
+               return;
+
+       for (int i = 0; i < hpc->total; i++) {
+               if (hpc->fd[i] != -1)
+                       close(hpc->fd[i]);
        }
 
-       hpc.total = 0;
-       hpc.idx = -1;
-       hpc.len = 0;
+       hpc->total = 0;
+       hpc->idx = -1;
+       hpc->len = 0;
 }
 
 static int hp_get_cached(uint64_t len)
 {
        int fd;
 
-       if (hpc.idx < 0 || len != hpc.len)
+       if (NULL == hpc || hpc->idx < 0 || len != hpc->len)
                return -1;
 
-       fd = hpc.fd[hpc.idx];
-       hpc.fd[hpc.idx--] = -1;
+       fd = hpc->fd[hpc->idx];
+       hpc->fd[hpc->idx--] = -1;
 
        return fd;
 }
 
 static int hp_put_cached(int fd)
 {
-       if (odp_unlikely(++hpc.idx >= hpc.total)) {
-               hpc.idx--;
+       if (NULL == hpc || odp_unlikely(++hpc->idx >= hpc->total)) {
+               hpc->idx--;
                ODP_ERR("Trying to put more FD than allowed: %d\n", fd);
                return -1;
        }
 
-       hpc.fd[hpc.idx] = fd;
+       hpc->fd[hpc->idx] = fd;
 
        return 0;
 }