On 02/18, Christoph Hellwig wrote:
> This still has a file system sysfs HACK, you're still not Ccing the
> right list, etc.
>
> Can you pleae at least try to get it right?
I was modifying the patch having 1) declaring a static global list, 2) adding
some fields to superblock and inode structures to keep the given range in the
inode through fadvise, 3) adding hooks in evict_inode to handle the list, 4)
exploring which sysfs entry in MM to reclaim them explicitly.
But, I stopped at some point, as it looks not good at all. Moreover, I started
to be questioning why not just doing in F2FS back, given sementically I didn't
change anything on general behavior of fadvise(POSIX_FADV_NOREUSE), IIUC, which
moves pages back to LRU. In addiiton to that, I'd like to keep the range hint in
a filesystem and provide a sysfs entry to manage the hints additionally.
In addition, I don't think there's rule that filesystem cannot reclaim file-back
pages, as it just uses the exported symbol that all filesystems are using in
various different purpose. Hence, I don't get the point which is wrong.
Thanks,
>
> On Wed, Feb 12, 2025 at 02:31:55AM +0000, Jaegeuk Kim wrote:
> > This patch series does not add new API, but implements POSIX_FADV_NOREUSE where
> > it keeps the page ranges in the f2fs superblock and add a way for users to
> > reclaim the pages manually.
> >
> > Change log from v8:
> > - remove new APIs, but use fadvise(POSIX_FADV_NOREUSE)
> >
> > Jaegeuk Kim (2):
> > f2fs: keep POSIX_FADV_NOREUSE ranges
> > f2fs: add a sysfs entry to reclaim POSIX_FADV_NOREUSE pages
> >
> > Documentation/ABI/testing/sysfs-fs-f2fs | 7 ++
> > fs/f2fs/debug.c | 3 +
> > fs/f2fs/f2fs.h | 14 +++-
> > fs/f2fs/file.c | 60 +++++++++++++++--
> > fs/f2fs/inode.c | 14 ++++
> > fs/f2fs/shrinker.c | 90 +++++++++++++++++++++++++
> > fs/f2fs/super.c | 1 +
> > fs/f2fs/sysfs.c | 63 +++++++++++++++++
> > 8 files changed, 246 insertions(+), 6 deletions(-)
> >
> > --
> > 2.48.1.601.g30ceb7b040-goog
> >
> >
> ---end quoted text---