Clarify that certain parameters are likely to be rounded to page-size

by the operating system.

bin/varnishd/mgt/mgt_param.c

@@ -695,12 +695,14 @@ static const struct parspec input_parspec[] = {
 		"120", "seconds" },
 	{ "workspace_client",
 		tweak_bytes_u, &mgt_param.workspace_client, 3072, UINT_MAX,
-		"Bytes of HTTP protocol workspace for clients HTTP req/resp.",
+		"Bytes of HTTP protocol workspace for clients HTTP req/resp."
+		"  If larger than 4k, use a multiple of 4k for VM efficiency.",
 		DELAYED_EFFECT,
 		"64k", "bytes" },
 	{ "workspace_backend",
 		tweak_bytes_u, &mgt_param.workspace_backend, 1024, UINT_MAX,
-		"Bytes of HTTP protocol workspace for backend HTTP req/resp.",
+		"Bytes of HTTP protocol workspace for backend HTTP req/resp."
+		"  If larger than 4k, use a multiple of 4k for VM efficiency.",
 		DELAYED_EFFECT,
 		"64k", "bytes" },
 	{ "workspace_thread",

bin/varnishd/mgt/mgt_pool.c

@@ -66,7 +66,7 @@ tweak_thread_pool_min(struct cli *cli, const struct parspec *par,
 /*--------------------------------------------------------------------
  * This is utterly ridiculous:  POSIX does not guarantee that the
  * minimum thread stack size is a compile time constant.
- * XXX: "32" is a magic marker for 32bit systems.
+ * XXX: "32bit" is a magic marker for 32bit systems.
  */
 
 static void
@@ -220,6 +220,7 @@ const struct parspec WRK_parspec[] = {
 	{ "thread_pool_stack",
 		tweak_stack_size, &mgt_param.wthread_stacksize, 0, UINT_MAX,
 		"Worker thread stack size.\n"
+		"This is likely rounded up to a multiple of 4k by the kernel.\n"
 		"On 32bit systems you may need to tweak this down to fit "
 		"many threads into the limited address space.\n",
 		EXPERIMENTAL,