On Wed 2024-02-28 15:00:01, Geert Uytterhoeven wrote:
> Hi all,
>
> When printk-indexing is enabled, each printk() invocation emits a
> pi_entry structure, containing the format string and other information
> related to its location in the kernel sources. This is even true when
> the printk() is protected by an always-false check, as is typically the
> case for debug messages: while the actual code to print the message is
> optimized out by the compiler, the pi_entry structure is still emitted.
> Hence when debugging is disabled, this leads to the inclusion in the
> index of lots of printk formats that cannot be emitted by the current
> kernel.
>
> This series fixes that for the common debug helpers under include/.
> It reduces the size of an arm64 defconfig kernel with
> CONFIG_PRINTK_INDEX=y by ca. 1.5 MiB, or 28% of the overhead of
> enabling CONFIG_PRINTK_INDEX=y.
>
> Notes:
> - netdev_(v)dbg() and netif_(v)dbg() are not affected, as
> net{dev,if}_printk() do not implement printk-indexing, except
> for the single global internal instance of __netdev_printk().
> - This series fixes only debug code in global header files under
> include/. There are more cases to fix in subsystem-specific header
> files and in sources files.
>
> Thanks for your comments!
>
> Geert Uytterhoeven (4):
> printk: Let no_printk() use _printk()
> dev_printk: Add and use dev_no_printk()
> dyndbg: Use *no_printk() helpers
> ceph: Use no_printk() helper
>
> include/linux/ceph/ceph_debug.h | 18 +++++++-----------
> include/linux/dev_printk.h | 25 +++++++++++++------------
> include/linux/dynamic_debug.h | 4 ++--
> include/linux/printk.h | 2 +-
> 4 files changed, 23 insertions(+), 26 deletions(-)
The whole series looks good to me:
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
I am going take it via printk tree for 6.10.
I am sorry that I haven't looked at it in time before the merge
window for 6.9. I have been snowed under various tasks. The changes
are not complicated. But they also are not critical to be pushed
an expedite way.
Best Regards,
Petr
