Messages in this thread Patch in this message | | | From | Guanghui Feng <> | Subject | [PATCH] arm64: clear_page: use stnp non-temporal instruction for performance optimizing | Date | Tue, 16 Nov 2021 23:08:14 +0800 |
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When clear page mem, there is no need to alloc cache for storing these mem value. And the copy_page.S have used stnp instruction for optimizing. So I rewrite the clear_page.S with stnp. At the same time, I have tested it with stnp instruction which will get about twice the performance improvement.
Signed-off-by: Guanghui Feng <guanghuifeng@linux.alibaba.com> --- arch/arm64/lib/clear_page.S | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/lib/clear_page.S b/arch/arm64/lib/clear_page.S index b84b179..e9dc2d6 100644 --- a/arch/arm64/lib/clear_page.S +++ b/arch/arm64/lib/clear_page.S @@ -15,13 +15,18 @@ * x0 - dest */ SYM_FUNC_START_PI(clear_page) - mrs x1, dczid_el0 - and w1, w1, #0xf - mov x2, #4 - lsl x1, x2, x1 - -1: dc zva, x0 - add x0, x0, x1 + mov x1, #0 + mov x2, #0 +1: + stnp x1, x2, [x0] + stnp x1, x2, [x0, #16] + stnp x1, x2, [x0, #32] + stnp x1, x2, [x0, #48] + stnp x1, x2, [x0, #64] + stnp x1, x2, [x0, #80] + stnp x1, x2, [x0, #96] + stnp x1, x2, [x0, #112] + add x0, x0, #128 tst x0, #(PAGE_SIZE - 1) b.ne 1b ret -- 1.8.3.1
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