musl: mips: add vdso support

vdso support is available on mips starting with kernel 4.4, see kernel
commit a7f4df4e21 "MIPS: VDSO: Add implementations of gettimeofday()
and clock_gettime()" for details.

These are my micro benchmark results for 1.000.000 calls to
clock_gettime(CLOCK_MONOTONIC, &tp)

without vdso:
root@OpenWrt:/# time ./vdso-test
real 0m 0.95s
user 0m 0.24s
sys 0m 0.70s

with vdso:
root@OpenWrt:/# time /usr/bin/vdso-test
real 0m 0.35s
user 0m 0.34s
sys 0m 0.00s

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 48466
This commit is contained in:
Hauke Mehrtens 2016-01-23 23:48:55 +00:00
parent 9d0703f016
commit b5d6256ca8

View File

@ -0,0 +1,29 @@
From c29a29c3334344e0f3cfdec6130a6261514507a0 Mon Sep 17 00:00:00 2001
From: Hauke Mehrtens <hauke@hauke-m.de>
Date: Sat, 23 Jan 2016 16:23:09 +0100
Subject: [PATCH 2/2] mips: add vdso support
vdso support is available on mips starting with kernel 4.4, see kernel
commit a7f4df4e21 "MIPS: VDSO: Add implementations of gettimeofday()
and clock_gettime()" for details.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
arch/mips/syscall_arch.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/mips/syscall_arch.h b/arch/mips/syscall_arch.h
index e74e0ad..39c0ea3 100644
--- a/arch/mips/syscall_arch.h
+++ b/arch/mips/syscall_arch.h
@@ -161,3 +161,7 @@ static inline long __syscall6(long n, long a, long b, long c, long d, long e, lo
if (n == SYS_fstatat) __stat_fix(c);
return r2;
}
+
+#define VDSO_USEFUL
+#define VDSO_CGT_SYM "__vdso_clock_gettime"
+#define VDSO_CGT_VER "LINUX_2.6"
--
2.7.0.rc3