From 4bd9b0f4afc76cf972578c702e1bc1b6f2d10ba5 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Wed, 24 Jun 2009 15:37:45 -0400 Subject: nfsd41: use globals for DRC limits The version 4.1 DRC memory limit and tracking variables are server wide and session specific. Replace struct svc_serv fields with globals. Stop using the svc_serv sv_lock. Add a spinlock to serialize access to the DRC limit management variables which change on session creation and deletion (usage counter) or (future) administrative action to adjust the total DRC memory limit. Signed-off-by: Andy Adamson Signed-off-by: Benny Halevy --- fs/nfsd/nfs4state.c | 10 +++++----- fs/nfsd/nfssvc.c | 19 +++++++++++++++---- 2 files changed, 20 insertions(+), 9 deletions(-) (limited to 'fs/nfsd') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 980a216..2e6a44e 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -430,11 +430,11 @@ static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan) else if (fchan->maxreqs > NFSD_MAX_SLOTS_PER_SESSION) fchan->maxreqs = NFSD_MAX_SLOTS_PER_SESSION; - spin_lock(&nfsd_serv->sv_lock); - if (np + nfsd_serv->sv_drc_pages_used > nfsd_serv->sv_drc_max_pages) - np = nfsd_serv->sv_drc_max_pages - nfsd_serv->sv_drc_pages_used; - nfsd_serv->sv_drc_pages_used += np; - spin_unlock(&nfsd_serv->sv_lock); + spin_lock(&nfsd_drc_lock); + if (np + nfsd_drc_pages_used > nfsd_drc_max_pages) + np = nfsd_drc_max_pages - nfsd_drc_pages_used; + nfsd_drc_pages_used += np; + spin_unlock(&nfsd_drc_lock); if (np <= 0) { status = nfserr_resource; diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index d4c9884..78d8fcd 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -67,6 +67,16 @@ struct timeval nfssvc_boot; DEFINE_MUTEX(nfsd_mutex); struct svc_serv *nfsd_serv; +/* + * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used. + * nfsd_drc_max_pages limits the total amount of memory available for + * version 4.1 DRC caches. + * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage. + */ +spinlock_t nfsd_drc_lock; +unsigned int nfsd_drc_max_pages; +unsigned int nfsd_drc_pages_used; + #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) static struct svc_stat nfsd_acl_svcstats; static struct svc_version * nfsd_acl_version[] = { @@ -238,11 +248,12 @@ static void set_max_drc(void) { /* The percent of nr_free_buffer_pages used by the V4.1 server DRC */ #define NFSD_DRC_SIZE_SHIFT 7 - nfsd_serv->sv_drc_max_pages = nr_free_buffer_pages() + nfsd_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); + nfsd_drc_pages_used = 0; + spin_lock_init(&nfsd_drc_lock); + dprintk("%s nfsd_drc_max_pages %u\n", __func__, + nfsd_drc_max_pages); } int nfsd_create_serv(void) -- cgit v1.1