> On Jun 21, 2017, at 10:31 AM, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > >> >> On Jun 20, 2017, at 7:35 PM, Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> wrote: >> >> The following patches are intended to smooth out the page writeback >> performance by ensuring that we commit the data earlier on the server. >> >> 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. > > These are the same as the patches you sent May 16th? > I am trying to get a little time to try them out. After applying these four patches, I ran a series of iozone benchmarks with buffered and direct I/O. NFSv3 and NFSv4.0 on RDMA. Exports were tmpfs and xfs on NVMe. I see about a 10% improvement in buffered write throughput, no degradation elsewhere, and no crashes or other misbehav- ior. xfstests passes with the usual few failures. Buffered write throughput is still limited to 1GBps when targeting a tmpfs export on a 5.6GBps network. The server isn't breaking a sweat, but the client appears to be hit- ting some spin locks pretty hard. This is similar behavior to before the patches were applied. >> 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.html > > -- > Chuck Lever > > > > -- > 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.html -- Chuck Lever -- 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.html
