Messages in this thread | | | From | Anup Patel <> | Date | Sun, 26 Jun 2022 10:03:07 +0530 | Subject | Re: [PATCH v4 0/2] use static key to optimize pgtable_l4_enabled |
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On Sat, May 21, 2022 at 8:13 PM Jisheng Zhang <jszhang@kernel.org> wrote: > > The pgtable_l4|[l5]_enabled check sits at hot code path, performance > is impacted a lot. Since pgtable_l4|[l5]_enabled isn't changed after > boot, so static key can be used to solve the performance issue[1]. > > An unified way static key was introduced in [2], but it only targets > riscv isa extension. We dunno whether SV48 and SV57 will be considered > as isa extension, so the unified solution isn't used for > pgtable_l4[l5]_enabled now. > > patch1 fixes a NULL pointer deference if static key is used a bit earlier. > patch2 uses the static key to optimize pgtable_l4|[l5]_enabled. > > [1] http://lists.infradead.org/pipermail/linux-riscv/2021-December/011164.html > [2] https://lore.kernel.org/linux-riscv/20220517184453.3558-1-jszhang@kernel.org/T/#t > > Since v3: > - fix W=1 call to undeclared function 'static_branch_likely' error > > Since v2: > - move the W=1 warning fix to a separate patch > - move the unified way to use static key to a new patch series. > > Since v1: > - Add a W=1 warning fix > - Fix W=1 error > - Based on v5.18-rcN, since SV57 support is added, so convert > pgtable_l5_enabled as well. > > > > Jisheng Zhang (2): > riscv: move sbi_init() earlier before jump_label_init() > riscv: turn pgtable_l4|[l5]_enabled to static key for RV64
I have tested both these patches on QEMU RV64 and RV32.
Tested-by: Anup Patel <anup@brainfault.org>
Thanks, Anup
> > arch/riscv/include/asm/pgalloc.h | 16 ++++---- > arch/riscv/include/asm/pgtable-32.h | 3 ++ > arch/riscv/include/asm/pgtable-64.h | 60 ++++++++++++++++++--------- > arch/riscv/include/asm/pgtable.h | 5 +-- > arch/riscv/kernel/cpu.c | 4 +- > arch/riscv/kernel/setup.c | 2 +- > arch/riscv/mm/init.c | 64 ++++++++++++++++++----------- > arch/riscv/mm/kasan_init.c | 16 ++++---- > 8 files changed, 104 insertions(+), 66 deletions(-) > > -- > 2.34.1 >
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