On Apr. 28, 2009, 19:59 +0300, andros@xxxxxxxxxx wrote:
> From: Andy Adamson <andros@xxxxxxxxxx>
>
> The version 4.1 DRC memory limit and tracking variables are server wide and
> session specific.
> Add a spinlock to serialize access to the management variables which change
> on session creation and deletion (usage counter) or (future) administrative
> action to adjust the total DRC memory limit.
>
> Track DRC memory usage in free session.
>
> Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 11 +++++++----
> fs/nfsd/nfssvc.c | 19 +++++++++++++++----
> include/linux/nfsd/nfsd.h | 5 +++++
> include/linux/sunrpc/svc.h | 2 --
> 4 files changed, 27 insertions(+), 10 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index d12220c..a9e722e 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -416,7 +416,7 @@ gen_sessionid(struct nfsd4_session *ses)
>
> /*
> * Give the client the number of slots it requests bound by
> - * NFSD_MAX_SLOTS_PER_SESSION and by sv_drc_max_pages.
> + * NFSD_MAX_SLOTS_PER_SESSION and by nfsd_drc_max_mem.
> *
> * If we run out of reserved DRC memory we should (up to a point) re-negotiate
> * active sessions and reduce their slot usage to make rooom for new
> @@ -434,9 +434,9 @@ static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan)
> mem = fchan->maxreqs * NFSD_SLOT_CACHE_SIZE;
>
> spin_lock(&nfsd_serv->sv_lock);
Hmm, shouldn't you grab nfsd_drc_lock instead?
> - if (mem + nfsd_serv->sv_drc_mem_used > nfsd_serv->sv_drc_max_mem)
> - mem = nfsd_serv->sv_drc_max_mem - nfsd_serv->sv_drc_mem_used;
> - nfsd_serv->sv_drc_mem_used += mem;
> + if (mem + nfsd_drc_mem_used > nfsd_drc_max_mem)
> + mem = nfsd_drc_max_mem - nfsd_drc_mem_used;
> + nfsd_drc_mem_used += mem;
> spin_unlock(&nfsd_serv->sv_lock);
and unlock nfsd_drc_lock
Benny
>
> if (mem < NFSD_SLOT_CACHE_SIZE) {
> @@ -588,6 +588,9 @@ free_session(struct kref *kref)
> struct nfsd4_cache_entry *e = &ses->se_slots[i].sl_cache_entry;
> nfsd4_release_respages(e->ce_respages, e->ce_resused);
> }
> + spin_lock(&nfsd_drc_lock);
> + nfsd_drc_mem_used -= ses->se_fchannel.maxreqs * NFSD_SLOT_CACHE_SIZE;
> + spin_unlock(&nfsd_drc_lock);
> kfree(ses);
> }
>
> diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
> index 80588cc..37633f5 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_mem;
> +unsigned int nfsd_drc_mem_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[] = {
> @@ -238,12 +248,13 @@ 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 10
> - nfsd_serv->sv_drc_max_mem = (nr_free_buffer_pages()
> + nfsd_drc_max_mem = (nr_free_buffer_pages()
> >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
> - nfsd_serv->sv_drc_mem_used = 0;
> + nfsd_drc_mem_used = 0;
> + spin_lock_init(&nfsd_drc_lock);
> dprintk("%s svc_drc_max_mem %u [in pages %lu]\n", __func__,
> - nfsd_serv->sv_drc_max_mem,
> - nfsd_serv->sv_drc_max_mem / PAGE_SIZE);
> + nfsd_drc_max_mem,
> + nfsd_drc_max_mem / PAGE_SIZE);
> }
>
> int nfsd_create_serv(void)
> diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
> index 9cd6399..23ba7bd 100644
> --- a/include/linux/nfsd/nfsd.h
> +++ b/include/linux/nfsd/nfsd.h
> @@ -56,6 +56,11 @@ extern struct svc_version nfsd_version2, nfsd_version3,
> extern u32 nfsd_supported_minorversion;
> extern struct mutex nfsd_mutex;
> extern struct svc_serv *nfsd_serv;
> +extern spinlock_t nfsd_drc_lock;
> +extern unsigned int nfsd_drc_max_mem;
> +extern unsigned int nfsd_drc_mem_used;
> +
> +
>
> extern struct seq_operations nfs_exports_op;
>
> diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
> index 243508e..d0d8bf4 100644
> --- a/include/linux/sunrpc/svc.h
> +++ b/include/linux/sunrpc/svc.h
> @@ -94,8 +94,6 @@ 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_mem; /* Total pages for DRC */
> - unsigned int sv_drc_mem_used;/* DRC pages used */
> };
>
> /*
--
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