kernel - Adjust mbuf cached free object retention

* Adjust the cache retention in the objcache_create() calls the mbuf
  subsystem makes to reduce burst ENOBUF failures.  Previously the
  main mbufphdr cache only retained ~150 or so free mbufs.  Now it
  retains up to 1/4 the limit.

Reported-by: Peter Avalos <peter@theshell.com>

diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index b34a8f0..440a7ea 100644 (file)
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -638,48 +638,56 @@ mbinit(void *dummy)
        mb_limit = cl_limit = 0;
 
        limit = nmbufs;
-       mbuf_cache = objcache_create("mbuf", &limit, 0,
+       mbuf_cache = objcache_create("mbuf",
+           &limit, 0,
            mbuf_ctor, NULL, NULL,
            objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args);
        mb_limit += limit;
 
        limit = nmbufs;
-       mbufphdr_cache = objcache_create("mbuf pkt hdr", &limit, 128,
+       mbufphdr_cache = objcache_create("mbuf pkt hdr",
+           &limit, nmbufs / 4,
            mbufphdr_ctor, NULL, NULL,
            objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args);
        mb_limit += limit;
 
        cl_limit = nmbclusters;
-       mclmeta_cache = objcache_create("cluster mbuf", &cl_limit, 0,
+       mclmeta_cache = objcache_create("cluster mbuf",
+           &cl_limit, 0,
            mclmeta_ctor, mclmeta_dtor, NULL,
            objcache_malloc_alloc, objcache_malloc_free, &mclmeta_malloc_args);
 
        cl_limit = nmbclusters;
-       mjclmeta_cache = objcache_create("jcluster mbuf", &cl_limit, 0,
+       mjclmeta_cache = objcache_create("jcluster mbuf",
+           &cl_limit, 0,
            mjclmeta_ctor, mclmeta_dtor, NULL,
            objcache_malloc_alloc, objcache_malloc_free, &mclmeta_malloc_args);
 
        limit = nmbclusters;
-       mbufcluster_cache = objcache_create("mbuf + cluster", &limit, 0,
+       mbufcluster_cache = objcache_create("mbuf + cluster",
+           &limit, 0,
            mbufcluster_ctor, mbufcluster_dtor, NULL,
            objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args);
        mb_limit += limit;
 
        limit = nmbclusters;
        mbufphdrcluster_cache = objcache_create("mbuf pkt hdr + cluster",
-           &limit, 128, mbufphdrcluster_ctor, mbufcluster_dtor, NULL,
+           &limit, nmbclusters / 16,
+           mbufphdrcluster_ctor, mbufcluster_dtor, NULL,
            objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args);
        mb_limit += limit;
 
        limit = nmbclusters;
-       mbufjcluster_cache = objcache_create("mbuf + jcluster", &limit, 0,
+       mbufjcluster_cache = objcache_create("mbuf + jcluster",
+           &limit, 0,
            mbufjcluster_ctor, mbufcluster_dtor, NULL,
            objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args);
        mb_limit += limit;
 
        limit = nmbclusters;
        mbufphdrjcluster_cache = objcache_create("mbuf pkt hdr + jcluster",
-           &limit, 64, mbufphdrjcluster_ctor, mbufcluster_dtor, NULL,
+           &limit, nmbclusters / 16,
+           mbufphdrjcluster_ctor, mbufcluster_dtor, NULL,
            objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args);
        mb_limit += limit;