On Fri, 2017-06-23 at 11:25 -0400, Trond Myklebust wrote: > On Fri, 2017-06-23 at 10:56 -0400, J. Bruce Fields wrote: > > On Tue, Jun 20, 2017 at 07:35:35PM -0400, Trond Myklebust wrote: > > > The following patches are intended to smooth out the page > > > writeback > > > performance by ensuring that we commit the data earlier on the > > > server. > > > > Was there some particular benchmark or hardware setup that > > motivated > > doing this now? > > I finally had enough free time to study the problem of why my backups > from my laptop to my NAS backup device took so long to complete, and > why the 'rsync' bandwidth display is so inconsistent. The NAS device in question is a no-name brand NFSv3 box, BTW. No fancy pNFS or even SSDs. > > > > > --b. > > > > > > > > We assume that if something is starting writeback on the pages, > > > then > > > that process wants to commit the data as soon as possible, > > > whether > > > it > > > is an application or just the background flush process. > > > We also assume that for streaming type processes, we don't want > > > to > > > pause > > > the I/O in order to commit, so we don't want to rely on a counter > > > of > > > in-flight I/O to the entire inode going to zero. > > > > > > We therefore set up a monitor that counts the number of in-flight > > > writes for each call to nfs_writepages(). Once all the writes to > > > that > > > call to nfs_writepages has completed, we send the commit. Note > > > that > > > this > > > mirrors the behaviour for O_DIRECT writes, where we similarly > > > track > > > the > > > in-flight writes on a per-call basis. > > > > > > Trond Myklebust (3): > > > NFS: Remove unused fields in the page I/O structures > > > NFS: Ensure we commit after writeback is complete > > > NFS: Fix commit policy for non-blocking calls to > > > nfs_write_inode() > > > > > > fs/nfs/pagelist.c | 5 ++-- > > > fs/nfs/write.c | 59 > > > +++++++++++++++++++++++++++++++++++++++++++++++- > > > include/linux/nfs_page.h | 2 +- > > > include/linux/nfs_xdr.h | 3 ++- > > > 4 files changed, 64 insertions(+), 5 deletions(-) > > > > > > -- > > > 2.9.4 > > > > > > -- > > > To unsubscribe from this list: send the line "unsubscribe linux- > > > nfs" in > > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More majordomo info at http://vger.kernel.org/majordomo-info.htm > > > l > > > > -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@xxxxxxxxxxxxxxx ��.n��������+%������w��{.n�����{��w��� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
