[PATCH 0/8] riscv/mm/fault: Page fault handler cleanups
penberg at gmail.com
Tue Aug 25 15:08:50 EDT 2020
On Tue, Aug 25, 2020 at 9:39 PM Pekka Enberg <penberg at gmail.com> wrote:
> From: Pekka Enberg <penberg at kernel.org>
> This patch series cleans up the do_page_fault() function by replacing
> gotos with function calls, similar to what the x86 architecture does.
> The motivation for this series is to make thepage fault handling code
> easier to read and reason about.
> The use of gotos has no advantage in kernel code size either. In fact,
> the bloatometer script shows a tiny decrease in kernel text size:
> add/remove: 1/0 grow/shrink: 0/2 up/down: 96/-99 (-3)
> Function old new delta
> no_context.part - 96 +96
> __func__ 14 13 -1
> do_page_fault 778 680 -98
> Total: Before=792, After=789, chg -0.38%
> Please note tht x86 also moves these functions out-of-line with the
> "noinline" annotation, which supposedly decreases stack usage in
> do_page_fault() at the expense of slighly larger kernel code size.
> However, in my testing, I was able to reduce stack usage at maximum by
> 16 bytes, at the expense of much larger kernel code size, so I am
> keeping the functions inline, and letting the compiler do its job.
> The patch series has been tested on QEMU.
> You can pull the series from:
> git at github.com:penberg/linux.git penberg/riscv/mm-fault-cleanups
Of course I forgot the sign-off... :-/
Signed-off-by: Pekka Enberg <penberg at kernel.org>
(Updated the commits in the tree behind that git URL to also have the
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