---

yaml
---
r: 142195
b: refs/heads/master
c: c3d06f9
h: refs/heads/master
i:
  142193: 7e1274e
  142191: 4c2a247
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 074fe897536f095309c5aaffcf912952882ab2cb
+refs/heads/master: c3d06f9ce8544fecfe13e377d1e2c2e47fe18dbc

trunk/fs/nfsd/nfssvc.c

@@ -22,6 +22,7 @@
 #include <linux/freezer.h>
 #include <linux/fs_struct.h>
 #include <linux/kthread.h>
+#include <linux/swap.h>
 
 #include <linux/sunrpc/types.h>
 #include <linux/sunrpc/stats.h>
@@ -197,6 +198,26 @@ void nfsd_reset_versions(void)
 	}
 }
 
+/*
+ * Each session guarantees a negotiated per slot memory cache for replies
+ * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
+ * NFSv4.1 server might want to use more memory for a DRC than a machine
+ * with mutiple services.
+ *
+ * Impose a hard limit on the number of pages for the DRC which varies
+ * according to the machines free pages. This is of course only a default.
+ *
+ * For now this is a #defined shift which could be under admin control
+ * in the future.
+ */
+static void set_max_drc(void)
+{
+	nfsd_serv->sv_drc_max_pages = nr_free_buffer_pages()
+						>> NFSD_DRC_SIZE_SHIFT;
+	nfsd_serv->sv_drc_pages_used = 0;
+	dprintk("%s svc_drc_max_pages %u\n", __func__,
+		nfsd_serv->sv_drc_max_pages);
+}
 
 int nfsd_create_serv(void)
 {
@@ -229,6 +250,8 @@ int nfsd_create_serv(void)
 				      nfsd_last_thread, nfsd, THIS_MODULE);
 	if (nfsd_serv == NULL)
 		err = -ENOMEM;
+	else
+		set_max_drc();
 
 	do_gettimeofday(&nfssvc_boot);		/* record boot time */
 	return err;

trunk/include/linux/nfsd/nfsd.h

@@ -331,6 +331,9 @@ extern struct timeval	nfssvc_boot;
 #define NFSD_LEASE_TIME                 (nfs4_lease_time())
 #define NFSD_LAUNDROMAT_MINTIMEOUT      10   /* seconds */
 
+/* The percent of nr_free_buffer_pages used by the V4.1 server DRC */
+#define NFSD_DRC_SIZE_SHIFT	7
+
 /*
  * The following attributes are currently not supported by the NFSv4 server:
  *    ARCHIVE       (deprecated anyway)

trunk/include/linux/sunrpc/svc.h

@@ -95,6 +95,8 @@ struct svc_serv {
 	struct module *		sv_module;	/* optional module to count when
 						 * adding threads */
 	svc_thread_fn		sv_function;	/* main function for threads */
+	unsigned int		sv_drc_max_pages; /* Total pages for DRC */
+	unsigned int		sv_drc_pages_used;/* DRC pages used */
 };
 
 /*