On Wed, Sep 06, 2023 at 01:58:49PM +0200, Alexey Gladkov wrote:
> On Tue, Aug 29, 2023 at 01:44:55PM -0700, Luis Chamberlain wrote:
> > The following changes since commit 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5:
> >
> > Linux 6.5-rc1 (2023-07-09 13:53:13 -0700)
> >
> > are available in the Git repository at:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/
> > tags/sysctl-6.6-rc1
> >
> > for you to fetch changes up to 53f3811dfd5e39507ee3aaea1be09aabce8f9c98:
> >
> > sysctl: Use ctl_table_size as stopping criteria for list macro
> > (2023-08-15 15:26:18 -0700)
> >
> >
> > sysctl-6.6-rc1
> >
> > Long ago we set out to remove the kitchen sink on kernel/sysctl.c arrays and
> > placings sysctls to their own sybsystem or file to help avoid merge
> > conflicts.
> > Matthew Wilcox pointed out though that if we're going to do that we might as
> > well also *save* space while at it and try to remove the extra last sysctl
> > entry added at the end of each array, a sentintel, instead of bloating the
> > kernel by adding a new sentinel with each array moved.
> >
> > Doing that was not so trivial, and has required slowing down the moves of
> > kernel/sysctl.c arrays and measuring the impact on size by each new move.
> >
> > The complex part of the effort to help reduce the size of each sysctl is
> > being
> > done by the patient work of el señor Don Joel Granados. A lot of this is
> > truly
> > painful code refactoring and testing and then trying to measure the savings
> > of
> > each move and removing the sentinels. Although Joel already has code which
> > does
> > most of this work, experience with sysctl moves in the past shows is we
> > need to
> > be careful due to the slew of odd build failures that are possible due to
> > the
> > amount of random Kconfig options sysctls use.
> >
> > To that end Joel's work is split by first addressing the major housekeeping
> > needed to remove the sentinels, which is part of this merge request. The
> > rest
> > of the work to actually remove the sentinels will be done later in future
> > kernel releases.
>
> This is very interesting for me. I'm also refactoring sysctl based on
> discussion with Linus a while ago.
>
> Could you please add me to the Cc in the next patches?
I just sent the next batch for this set for review. You can see it here
https://lore.kernel.org/all/20230906-jag-sysctl_remove_empty_elem_arch-v1-0-3935d4854...@samsung.com/
Will add you for the next ones.
Best
>
> > At first I was only going to send his first 7 patches of his patch series,
> > posted 1 month ago, but in retrospect due to the testing the changes have
> > received in linux-next and the minor changes they make this goes with the
> > entire set of patches Joel had planned: just sysctl house keeping. There are
> > networking changes but these are part of the house keeping too.
> >
> > The preliminary math is showing this will all help reduce the overall build
> > time size of the kernel and run time memory consumed by the kernel by about
> > ~64 bytes per array where we are able to remove each sentinel in the future.
> > That also means there is no more bloating the kernel with the extra ~64
> > bytes
> > per array moved as no new sentinels are created.
> >
> > Most of this has been in linux-next for about a month, the last 7 patches
> > took
> > a minor refresh 2 week ago based on feedback.
> >
> >
> > Joel Granados (14):
> > sysctl: Prefer ctl_table_header in proc_sysctl
> > sysctl: Use ctl_table_header in list_for_each_table_entry
> > sysctl: Add ctl_table_size to ctl_table_header
> > sysctl: Add size argument to init_header
> > sysctl: Add a size arg to __register_sysctl_table
> > sysctl: Add size to register_sysctl
> > sysctl: Add size arg to __register_sysctl_init
> > sysctl: Add size to register_net_sysctl function
> > ax.25: Update to register_net_sysctl_sz
> > netfilter: Update to register_net_sysctl_sz
> > networking: Update to register_net_sysctl_sz
> > vrf: Update to register_net_sysctl_sz
> > sysctl: SIZE_MAX->ARRAY_SIZE in register_net_sysctl
> > sysctl: Use ctl_table_size as stopping criteria for list macro
> >
> > arch/arm64/kernel/armv8_deprecated.c| 2 +-
> > arch/s390/appldata/appldata_
