From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: [PATCH 10/44] nfsd41: change from page to memory based drc limits Date: Tue, 16 Jun 2009 21:58:23 -0400 Message-ID: <20090617015823.GF8980@fieldses.org> References: <1245115181-7130-1-git-send-email-bhalevy@panasas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: pnfs@linux-nfs.org, linux-nfs@vger.kernel.org To: Benny Halevy Return-path: Received: from mail.fieldses.org ([141.211.133.115]:40844 "EHLO pickle.fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751704AbZFQB6V (ORCPT ); Tue, 16 Jun 2009 21:58:21 -0400 In-Reply-To: <1245115181-7130-1-git-send-email-bhalevy@panasas.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Jun 16, 2009 at 04:19:41AM +0300, Benny Halevy wrote: > From: Andy Adamson > > 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 > Signed-off-by: Benny Halevy > --- > 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 90e6645..6489913 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -416,33 +416,34 @@ 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; Simpler: just fchan->maxreqs = mem / NFSD_SLOT_CACHE_SIZE; if (fchan->maxreqs == 0) status = nfserr_resource; --b. > + } > } > > /* > 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 eae086c..1ebb05e 100644 > --- a/include/linux/nfsd/state.h > +++ b/include/linux/nfsd/state.h > @@ -96,6 +96,7 @@ struct nfs4_cb_conn { > #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 */ > }; > > /* > -- > 1.6.3 >