Commit c3d06f9c authored by Andy Adamson's avatar Andy Adamson Committed by J. Bruce Fields
Browse files

nfsd41: hard page limit for DRC 



Use no more than 1/128th of the number of free pages at nfsd startup for the
v4.1 DRC.

This is an arbitrary default which should probably end up under the control
of an administrator.

Signed-off-by: default avatarAndy Adamson <andros@netapp.com>
[moved added fields in struct svc_serv under CONFIG_NFSD_V4_1]
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
[fix set_max_drc calculation of sv_drc_max_pages]
[moved NFSD_DRC_SIZE_SHIFT's declaration up in header file]
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 074fe897

fs/nfsd/nfssvc.c

+23 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/nfsd/nfsd.h

+3 −0
Original line number Diff line number Diff line
@@ -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)

include/linux/sunrpc/svc.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */

};



/*

CRA Git | Maintained and supported by SUSTech CRA and CCSE