From: "J. Bruce Fields" Subject: Re: Make sm-notify faster if there are no servers to notify Date: Fri, 5 Dec 2008 11:38:24 -0500 Message-ID: <20081205163824.GA29227@fieldses.org> References: <20081029173750.GD31936@fieldses.org> <1225302305994@dmwebmail.dmwebmail.chezphil.org> <20081029184153.GE31936@fieldses.org> <5AB39614-D03F-43DF-BCD2-2B2501A79D65@oracle.com> <20081029211145.GE1406@fieldses.org> <49183A12.7010707@RedHat.com> <20081204211057.GC9593@fieldses.org> <18744.41310.635618.148281@notabene.brown> <20081205035803.GC15115@fieldses.org> <49392C14.7000709@RedHat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Neil Brown , Chuck Lever , Phil Endecott , linux-nfs@vger.kernel.org To: Steve Dickson Return-path: Received: from mail.fieldses.org ([66.93.2.214]:52423 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750845AbYLEQig (ORCPT ); Fri, 5 Dec 2008 11:38:36 -0500 In-Reply-To: <49392C14.7000709-AfCzQyP5zfLQT0dZR+AlfA@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, Dec 05, 2008 at 08:26:44AM -0500, Steve Dickson wrote: > J. Bruce Fields wrote: > > > >> I think it would still be valuable to replace the 'sync' with two > >> 'fsync's, one of the file, one on the directory. > > > > Sure, may as well.--b. > > > Something similar to this: > > diff -up nfs-utils/utils/statd/sm-notify.c.orig nfs-utils/utils/statd/sm-notify.c > --- nfs-utils/utils/statd/sm-notify.c.orig 2008-11-17 15:06:13.000000000 -0500 > +++ nfs-utils/utils/statd/sm-notify.c 2008-12-05 08:21:52.000000000 -0500 > @@ -211,12 +211,6 @@ usage: fprintf(stderr, > backup_hosts(_SM_DIR_PATH, _SM_BAK_PATH); > get_hosts(_SM_BAK_PATH); > > - /* If there are not hosts to notify, just exit */ > - if (!hosts) { > - nsm_log(LOG_DEBUG, "No hosts to notify; exiting"); > - return 0; > - } This was still a huge boot-time win in the common case, so now that we've committed to it I'd rather not regress. Let's just skip the sync()s/fsncy()s in the !hosts case--that looks to me like the simplest correct solution for now. > - > /* Get and update the NSM state. This will call sync() */ > nsm_state = nsm_get_state(opt_update_state); > set_kernel_nsm_state(nsm_state); > @@ -694,6 +688,7 @@ nsm_get_state(int update) > { > char newfile[PATH_MAX]; > int fd, state; > + DIR *fp; > > if ((fd = open(_SM_STATE_PATH, O_RDONLY)) < 0) { > if (!opt_quiet) { > @@ -730,13 +725,16 @@ nsm_get_state(int update) > "Failed to write state to %s", newfile); > exit(1); > } > + fsync(fd); > close(fd); > + fp = opendir(_SM_STATE_PATH); Also, I think you meant to: fsync(fp); close(fp); ? --b. > if (rename(newfile, _SM_STATE_PATH) < 0) { > nsm_log(LOG_ERR, > "Cannot create %s: %m", _SM_STATE_PATH); > exit(1); > } > - sync(); > > If so, I'll make it happen... > > steved.