Limit rump kernel memory allotment to a hard upper limit.

This is a temporary hack to avoid the kernel trying to eat hundreds of
megs for caches.

diff --git a/lib/libbmk_rumpuser/rumpuser_base.c b/lib/libbmk_rumpuser/rumpuser_base.c
index 258e46b308adffb2a4387693b0f04141272ddb54..a68a7ff8e9238c5594955a2aeb062d4eaab530ab 100644 (file)
--- a/lib/libbmk_rumpuser/rumpuser_base.c
+++ b/lib/libbmk_rumpuser/rumpuser_base.c
@@ -52,6 +52,13 @@ rumpuser_init(int version, const struct rumpuser_hyperup *hyp)
        return rumprun_platform_rumpuser_init();
 }
 
+#define MIN(a,b) ((a) < (b) ? (a) : (b))
+
+/* attempt to give at least this much to the rump kernel */
+#define MEMSIZE_WARNLIMIT (8*1024*1024)
+/* give at most this much */
+#define MEMSIZE_HILIMIT (64*1024*1024)
+
 int
 rumpuser_getparam(const char *name, void *buf, size_t buflen)
 {
@@ -74,13 +81,13 @@ rumpuser_getparam(const char *name, void *buf, size_t buflen)
                char *res = buf;
                unsigned i, j;
 
-               /* use up to 50% memory for rump kernel */
-               memsize = bmk_platform_memsize() / 2;
-               if (memsize < (8 * 1024 * 1024)) {
-                       bmk_printf("rumphyper: warning: low on physical "
-                           "memory (%lu bytes), "
-                           "suggest increasing guest allocation\n", memsize);
-                       memsize = 8 * 1024 * 1024;
+               /* use 50% memory for rump kernel, with an upper limit */
+               memsize = MIN(MEMSIZE_HILIMIT, bmk_platform_memsize()/2);
+               if (memsize < MEMSIZE_WARNLIMIT) {
+                       bmk_printf("rump kernel warning: low on physical "
+                           "memory quota (%lu bytes)\n", memsize);
+                       bmk_printf("rump kernel warning: "
+                           "suggest increasing guest allocation\n");
                }
 
                for (i = 0; memsize > 0; i++) {