Date: Tue, 19 Dec 2017 23:00:08 +0000 (UTC) From: Rick Macklem <rmacklem@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r327008 - stable/10/sys/fs/nfsserver Message-ID: <201712192300.vBJN08oS071951@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: rmacklem Date: Tue Dec 19 23:00:08 2017 New Revision: 327008 URL: https://svnweb.freebsd.org/changeset/base/327008 Log: MFC: r326544 Avoid the overhead of acquiring a lock in nfsrv_checkgetattr() when there are no write delegations issued. manu@ reported on the freebsd-current@ mailing list that there was a significant performance hit in nfsrv_checkgetattr() caused by the acquisition/release of a state lock, even when there were no write delegations issued. This patch add a count of outstanding issued write delegations to the NFSv4 server. This count allows nfsrv_checkgetattr() to return without acquiring any lock when the count is 0, avoiding the performance hit for the case where no write delegations are issued. Modified: stable/10/sys/fs/nfsserver/nfs_nfsdstate.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/fs/nfsserver/nfs_nfsdstate.c ============================================================================== --- stable/10/sys/fs/nfsserver/nfs_nfsdstate.c Tue Dec 19 22:43:39 2017 (r327007) +++ stable/10/sys/fs/nfsserver/nfs_nfsdstate.c Tue Dec 19 23:00:08 2017 (r327008) @@ -98,6 +98,7 @@ static time_t nfsrvboottime; static int nfsrv_returnoldstateid = 0, nfsrv_clients = 0; static int nfsrv_clienthighwater = NFSRV_CLIENTHIGHWATER; static int nfsrv_nogsscallback = 0; +static volatile int nfsrv_writedelegcnt = 0; /* local functions */ static void nfsrv_dumpaclient(struct nfsclient *clp, @@ -1266,6 +1267,8 @@ nfsrv_freedeleg(struct nfsstate *stp) LIST_REMOVE(stp, ls_hash); LIST_REMOVE(stp, ls_list); LIST_REMOVE(stp, ls_file); + if ((stp->ls_flags & NFSLCK_DELEGWRITE) != 0) + nfsrv_writedelegcnt--; lfp = stp->ls_lfp; if (LIST_EMPTY(&lfp->lf_open) && LIST_EMPTY(&lfp->lf_lock) && LIST_EMPTY(&lfp->lf_deleg) && @@ -2902,6 +2905,7 @@ tryagain: new_deleg->ls_flags = (NFSLCK_DELEGWRITE | NFSLCK_READACCESS | NFSLCK_WRITEACCESS); *rflagsp |= NFSV4OPEN_WRITEDELEGATE; + nfsrv_writedelegcnt++; } else { new_deleg->ls_flags = (NFSLCK_DELEGREAD | NFSLCK_READACCESS); @@ -3032,6 +3036,7 @@ tryagain: new_deleg->ls_clp = clp; new_deleg->ls_filerev = filerev; new_deleg->ls_compref = nd->nd_compref; + nfsrv_writedelegcnt++; LIST_INSERT_HEAD(&lfp->lf_deleg, new_deleg, ls_file); LIST_INSERT_HEAD(NFSSTATEHASH(clp, new_deleg->ls_stateid), new_deleg, ls_hash); @@ -3089,6 +3094,7 @@ tryagain: new_deleg->ls_flags = (NFSLCK_DELEGWRITE | NFSLCK_READACCESS | NFSLCK_WRITEACCESS); *rflagsp |= NFSV4OPEN_WRITEDELEGATE; + nfsrv_writedelegcnt++; } else { new_deleg->ls_flags = (NFSLCK_DELEGREAD | NFSLCK_READACCESS); @@ -3165,6 +3171,7 @@ tryagain: NFSLCK_READACCESS | NFSLCK_WRITEACCESS); *rflagsp |= NFSV4OPEN_WRITEDELEGATE; + nfsrv_writedelegcnt++; } else { new_deleg->ls_flags = (NFSLCK_DELEGREAD | @@ -5289,6 +5296,8 @@ nfsrv_checkgetattr(struct nfsrv_descript *nd, vnode_t NFSCBGETATTR_ATTRBIT(attrbitp, &cbbits); if (!NFSNONZERO_ATTRBIT(&cbbits)) + goto out; + if (nfsrv_writedelegcnt == 0) goto out; /*
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201712192300.vBJN08oS071951>