Messages in this thread | | | From | Jisheng Zhang <> | Subject | [PATCH v5 0/2] use static key to optimize pgtable_l4_enabled | Date | Fri, 15 Jul 2022 21:48:45 +0800 |
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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 v4: - rebased on v5.19-rcN - collect Reviewed-by tags - Fix kernel panic issue if SPARSEMEM is enabled by moving the riscv_finalise_pgtable_lx() after sparse_init()
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
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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