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References: <20230119213351.443388-1-trondmy@kernel.org>
In-Reply-To: <20230119213351.443388-1-trondmy@kernel.org>
From:   Olga Kornievskaia <aglo@umich.edu>
Date:   Tue, 24 Jan 2023 11:07:31 -0500
Message-ID: <CAN-5tyFbSaaQBGHkOuckjqPP56QFS-=fF9TuYVLMiaFD0UBCTg@mail.gmail.com>
Subject: Re: [PATCH v2 00/18] Initial conversion of NFS basic I/O to use folios
To:     trondmy@kernel.org
Cc:     Anna Schumaker <Anna.Schumaker@netapp.com>,
        linux-nfs@vger.kernel.org
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On Fri, Jan 20, 2023 at 12:10 AM <trondmy@kernel.org> wrote:
>
> From: Trond Myklebust <trond.myklebust@hammerspace.com>
>
> This set of patches represents an initial effort to convert the page
> cache I/O in the NFS client to use native folio functionality. It should
> allow the nfs_page structs and their helpers to carry folios (including
> folios of order > 0) and to pass their data contents through to the RPC
> layer.
> Note that because O_DIRECT uses pages, we still need to support the
> traditional page based I/O, and so the new struct nfs_page will carry
> both types.
> I did not touch the fscache code, but I expect that to be able to
> continue to work with order 0 folios.
>
> The plan is to merge this functionality with order 0 folios first, in
> order to catch any regressions in existing functionality. Then we can
> enable order n > 0 once we're happy about the stability (at least for
> the non-fscache case).
>
> At this point, the xfstests are all passing without any regressions on
> my setup, so I'm throwing the patches over the fence to allow for wider
> testing.
> Please make sure, in particular to test pNFS if your server supports it.
> I didn't have to make any changes to the pNFS code, and I don't expect
> any trouble, but it would be good to have validation of that assumption.

Here's my experience with running with these patches running thru
xfstest's quick group:
Against a linux server: takes about a couple of minutes longer to run
with folio patches (48m with folio, 45 without) but that's just from 1
run with and and without.

Against an ontap server (so pnfs case):  total time is higher with
patches: I have a difference of 47m with folio and 38m without.

While I don't believe this is related to folio patches but I need to
increase my vm's size to 4g to have a successful run of xfstest. Tests
generic/531 and generic/460 are problematic with 2G. generic/531 leads
to oom-killer and generic/460 hangs.


>
> ---
> v2:
>  - Fix a bisectability issue reported by Anna
>  - Remove an unnecessary NULL pointer check in nfs_read_folio()
>
> Trond Myklebust (18):
>   NFS: Fix for xfstests generic/208
>   NFS: Add basic functionality for tracking folios in struct nfs_page
>   NFS: Support folios in nfs_generic_pgio()
>   NFS: Fix nfs_coalesce_size() to work with folios
>   NFS: Add a helper to convert a struct nfs_page into an inode
>   NFS: Convert the remaining pagelist helper functions to support folios
>   NFS: Add a helper nfs_wb_folio()
>   NFS: Convert buffered reads to use folios
>   NFS: Convert the function nfs_wb_page() to use folios
>   NFS: Convert buffered writes to use folios
>   NFS: Remove unused function nfs_wb_page()
>   NFS: Convert nfs_write_begin/end to use folios
>   NFS: Fix up nfs_vm_page_mkwrite() for folios
>   NFS: Clean up O_DIRECT request allocation
>   NFS: fix up nfs_release_folio() to try to release the page
>   NFS: Enable tracing of nfs_invalidate_folio() and nfs_launder_folio()
>   NFS: Improve tracing of nfs_wb_folio()
>   NFS: Remove unnecessary check in nfs_read_folio()
>
>  fs/nfs/direct.c          |  12 +-
>  fs/nfs/file.c            | 124 +++++++------
>  fs/nfs/internal.h        |  38 ++--
>  fs/nfs/nfstrace.h        |  58 ++++--
>  fs/nfs/pagelist.c        | 217 +++++++++++++++++-----
>  fs/nfs/pnfs.h            |  10 +-
>  fs/nfs/pnfs_nfs.c        |  18 +-
>  fs/nfs/read.c            |  94 +++++-----
>  fs/nfs/write.c           | 380 ++++++++++++++++++++-------------------
>  include/linux/nfs_fs.h   |   7 +-
>  include/linux/nfs_page.h |  79 +++++++-
>  11 files changed, 646 insertions(+), 391 deletions(-)
>
> --
> 2.39.0
>