[PATCH 08/30] nfsd41: change from page to memory based drc limits

andros
2009-06-08T18:21:21Z

NFSD_SLOT_CACHE_SIZE is the size of all encoded operation responses (excluding
the sequence operation) that we want to cache.

Adjust NFSD_DRC_SIZE_SHIFT to reflect using 512 bytes instead of PAGE_SIZE.

Signed-off-by: Andy Adamson <andros@netapp.com>
---
fs/nfsd/nfs4state.c | 29 +++++++++++++++--------------
fs/nfsd/nfssvc.c | 13 +++++++------
include/linux/nfsd/state.h | 1 +
include/linux/sunrpc/svc.h | 4 ++--
4 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3b05df3..52bd99c 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -418,33 +418,34 @@ 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.
*
- * If we run out of pages (sv_drc_pages_used == sv_drc_max_pages) we
- * should (up to a point) re-negotiate active sessions and reduce their
- * slot usage to make rooom for new connections. For now we just fail the
- * create session.
+ * 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
+ * connections. For now we just fail the create session.
*/
static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan)
{
- int status = 0, np = fchan->maxreqs * NFSD_PAGES_PER_SLOT;
+ int mem;

if (fchan->maxreqs < 1)
return nfserr_inval;
else if (fchan->maxreqs > NFSD_MAX_SLOTS_PER_SESSION)
fchan->maxreqs = NFSD_MAX_SLOTS_PER_SESSION;

+ mem = fchan->maxreqs * NFSD_SLOT_CACHE_SIZE;
+
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;
+ 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;
spin_unlock(&nfsd_serv->sv_lock);

- if (np <= 0) {
- status = nfserr_resource;
+ if (mem < NFSD_SLOT_CACHE_SIZE) {
fchan->maxreqs = 0;
- } else
- fchan->maxreqs = np / NFSD_PAGES_PER_SLOT;
-
- return status;
+ return nfserr_resource;
+ } else {
+ fchan->maxreqs = mem / NFSD_SLOT_CACHE_SIZE;
+ return 0;
+ }
}

/*
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index cbba4a9..80588cc 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -237,12 +237,13 @@ void nfsd_reset_versions(void)
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_SIZE_SHIFT;
- nfsd_serv->sv_drc_pages_used = 0;
- dprintk("%s svc_drc_max_pages %u\n", __func__,
- nfsd_serv->sv_drc_max_pages);
+ #define NFSD_DRC_SIZE_SHIFT 10
+ nfsd_serv->sv_drc_max_mem = (nr_free_buffer_pages()
+ >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
+ nfsd_serv->sv_drc_mem_used = 0;
+ 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);
}

int nfsd_create_serv(void)
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index aeb5e82..28ddb32 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -103,6 +103,7 @@ struct nfs4_callback {
#define NFSD_MAX_SLOTS_PER_SESSION 128
/* Maximum number of pages per slot cache entry */
#define NFSD_PAGES_PER_SLOT 1
+#define NFSD_SLOT_CACHE_SIZE 512
/* Maximum number of operations per session compound */
#define NFSD_MAX_OPS_PER_COMPOUND 16

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 2a30775..243508e 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -94,8 +94,8 @@ 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 */
+ unsigned int sv_drc_max_mem; /* Total pages for DRC */
+ unsigned int sv_drc_mem_used;/* DRC pages used */
};

/*
--
1.5.4.3