freebsd-dev/lib/libc/Makefile
Konstantin Belousov 1680854946 Implement userspace gettimeofday(2) with HPET timecounter.
Right now, userspace (fast) gettimeofday(2) on x86 only works for
RDTSC.  For older machines, like Core2, where RDTSC is not C2/C3
invariant, and which fall to HPET hardware, this means that the call
has both the penalty of the syscall and of the uncached hw behind the
QPI or PCIe connection to the sought bridge.  Nothing can me done
against the access latency, but the syscall overhead can be removed.
System already provides mappable /dev/hpetX devices, which gives
straight access to the HPET registers page.

Add yet another algorithm to the x86 'vdso' timehands. Libc is updated
to handle both RDTSC and HPET.  For HPET, the index of the hpet device
to mmap is passed from kernel to userspace, index might be changed and
libc invalidates its mapping as needed.

Remove cpu_fill_vdso_timehands() KPI, instead require that
timecounters which can be used from userspace, to provide
tc_fill_vdso_timehands{,32}() methods.  Merge i386 and amd64
libc/<arch>/sys/__vdso_gettc.c into one source file in the new
libc/x86/sys location.  __vdso_gettc() internal interface is changed
to move timecounter algorithm detection into the MD code.

Measurements show that RDTSC even with the syscall overhead is faster
than userspace HPET access.  But still, userspace HPET is three-four
times faster than syscall HPET on several Core2 and SandyBridge
machines.

Tested by:	Howard Su <howard0su@gmail.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D7473
2016-08-17 09:52:09 +00:00

205 lines
6.2 KiB
Makefile

# @(#)Makefile 8.2 (Berkeley) 2/3/94
# $FreeBSD$
PACKAGE= clibs
SHLIBDIR?= /lib
.include <src.opts.mk>
# Force building of libc_pic.a
MK_TOOLCHAIN= yes
LIBC_SRCTOP?= ${.CURDIR}
# Pick the current architecture directory for libc. In general, this is
# named MACHINE_CPUARCH, but some ABIs are different enough to require
# their own libc, so allow a directory named MACHINE_ARCH to override this.
.if exists(${LIBC_SRCTOP}/${MACHINE_ARCH})
LIBC_ARCH=${MACHINE_ARCH}
.else
LIBC_ARCH=${MACHINE_CPUARCH}
.endif
# All library objects contain FreeBSD revision strings by default; they may be
# excluded as a space-saving measure. To produce a library that does
# not contain these strings, add -DSTRIP_FBSDID (see <sys/cdefs.h>) to CFLAGS
# below. Note: there are no IDs for syscall stubs whose sources are generated.
# To include legacy CSRG sccsid strings, add -DLIBC_SCCS and -DSYSLIBC_SCCS
# to CFLAGS below. -DSYSLIBC_SCCS affects just the system call stubs.
LIB=c
SHLIB_MAJOR= 7
SHLIB_LDSCRIPT=libc.ldscript
SHLIB_LDSCRIPT_LINKS=libxnet.so
WARNS?= 2
CFLAGS+=-I${LIBC_SRCTOP}/include -I${LIBC_SRCTOP}/../../include
CFLAGS+=-I${LIBC_SRCTOP}/${LIBC_ARCH}
.if ${MK_NLS} != "no"
CFLAGS+=-DNLS
.endif
CLEANFILES+=tags
INSTALL_PIC_ARCHIVE=
PRECIOUSLIB=
.ifndef NO_THREAD_STACK_UNWIND
CANCELPOINTS_CFLAGS=-fexceptions
CFLAGS+=${CANCELPOINTS_CFLAGS}
.endif
#
# Link with static libcompiler_rt.a.
#
LDFLAGS+= -nodefaultlibs
LIBADD+= compiler_rt
.if ${MK_SSP} != "no"
LIBADD+= ssp_nonshared
.endif
# Extras that live in either libc.a or libc_nonshared.a
LIBC_NONSHARED_SRCS=
# Define (empty) variables so that make doesn't give substitution
# errors if the included makefiles don't change these:
MDSRCS=
MISRCS=
MDASM=
MIASM=
NOASM=
.include "${LIBC_SRCTOP}/${LIBC_ARCH}/Makefile.inc"
.include "${LIBC_SRCTOP}/db/Makefile.inc"
.include "${LIBC_SRCTOP}/compat-43/Makefile.inc"
.include "${LIBC_SRCTOP}/gdtoa/Makefile.inc"
.include "${LIBC_SRCTOP}/gen/Makefile.inc"
.include "${LIBC_SRCTOP}/gmon/Makefile.inc"
.if ${MK_ICONV} != "no"
.include "${LIBC_SRCTOP}/iconv/Makefile.inc"
.endif
.include "${LIBC_SRCTOP}/inet/Makefile.inc"
.include "${LIBC_SRCTOP}/isc/Makefile.inc"
.include "${LIBC_SRCTOP}/locale/Makefile.inc"
.include "${LIBC_SRCTOP}/md/Makefile.inc"
.include "${LIBC_SRCTOP}/nameser/Makefile.inc"
.include "${LIBC_SRCTOP}/net/Makefile.inc"
.include "${LIBC_SRCTOP}/nls/Makefile.inc"
.include "${LIBC_SRCTOP}/posix1e/Makefile.inc"
.if ${LIBC_ARCH} != "aarch64" && \
${LIBC_ARCH} != "amd64" && \
${LIBC_ARCH} != "powerpc64" && \
${LIBC_ARCH} != "riscv" && \
${LIBC_ARCH} != "sparc64" && \
${MACHINE_ARCH:Mmipsn32*} == "" && \
${MACHINE_ARCH:Mmips64*} == ""
.include "${LIBC_SRCTOP}/quad/Makefile.inc"
.endif
.include "${LIBC_SRCTOP}/regex/Makefile.inc"
.include "${LIBC_SRCTOP}/resolv/Makefile.inc"
.include "${LIBC_SRCTOP}/stdio/Makefile.inc"
.include "${LIBC_SRCTOP}/stdlib/Makefile.inc"
.include "${LIBC_SRCTOP}/stdlib/jemalloc/Makefile.inc"
.include "${LIBC_SRCTOP}/stdtime/Makefile.inc"
.include "${LIBC_SRCTOP}/string/Makefile.inc"
.include "${LIBC_SRCTOP}/sys/Makefile.inc"
.include "${LIBC_SRCTOP}/secure/Makefile.inc"
.include "${LIBC_SRCTOP}/rpc/Makefile.inc"
.include "${LIBC_SRCTOP}/uuid/Makefile.inc"
.include "${LIBC_SRCTOP}/xdr/Makefile.inc"
.if (${LIBC_ARCH} == "arm" && \
(${MACHINE_ARCH:Marmv6*} == "" || (defined(CPUTYPE) && ${CPUTYPE:M*soft*}))) || \
${LIBC_ARCH} == "mips"
.include "${LIBC_SRCTOP}/softfloat/Makefile.inc"
.endif
.if ${LIBC_ARCH} == "i386" || ${LIBC_ARCH} == "amd64"
.include "${LIBC_SRCTOP}/x86/sys/Makefile.inc"
.endif
.if ${MK_NIS} != "no"
CFLAGS+= -DYP
.include "${LIBC_SRCTOP}/yp/Makefile.inc"
.endif
.include "${LIBC_SRCTOP}/capability/Makefile.inc"
.if ${MK_HESIOD} != "no"
CFLAGS+= -DHESIOD
.endif
.if ${MK_FP_LIBC} == "no"
CFLAGS+= -DNO_FLOATING_POINT
.endif
.if ${MK_NS_CACHING} != "no"
CFLAGS+= -DNS_CACHING
.endif
.if defined(_FREEFALL_CONFIG)
CFLAGS+=-D_FREEFALL_CONFIG
.endif
STATICOBJS+=${LIBC_NONSHARED_SRCS:S/.c$/.o/}
VERSION_DEF=${LIBC_SRCTOP}/Versions.def
SYMBOL_MAPS=${SYM_MAPS}
CFLAGS+= -DSYMBOL_VERSIONING
# If there are no machine dependent sources, append all the
# machine-independent sources:
.if empty(MDSRCS)
SRCS+= ${MISRCS}
.else
# Append machine-dependent sources, then append machine-independent sources
# for which there is no machine-dependent variant.
SRCS+= ${MDSRCS}
.for _src in ${MISRCS}
.if ${MDSRCS:R:M${_src:R}} == ""
SRCS+= ${_src}
.endif
.endfor
.endif
KQSRCS= adddi3.c anddi3.c ashldi3.c ashrdi3.c cmpdi2.c divdi3.c iordi3.c \
lshldi3.c lshrdi3.c moddi3.c muldi3.c negdi2.c notdi2.c qdivrem.c \
subdi3.c ucmpdi2.c udivdi3.c umoddi3.c xordi3.c
KSRCS= bcmp.c ffs.c ffsl.c fls.c flsl.c mcount.c strcat.c strchr.c \
strcmp.c strcpy.c strlen.c strncpy.c strrchr.c
libkern: libkern.gen libkern.${LIBC_ARCH}
libkern.gen: ${KQSRCS} ${KSRCS}
${CP} ${LIBC_SRCTOP}/quad/quad.h ${.ALLSRC} ${DESTDIR}/sys/libkern
libkern.${LIBC_ARCH}:: ${KMSRCS}
.if defined(KMSRCS) && !empty(KMSRCS)
${CP} ${.ALLSRC} ${DESTDIR}/sys/libkern/${LIBC_ARCH}
.endif
.if ${MK_TESTS} != "no"
SUBDIR+= tests
.endif
.include <bsd.lib.mk>
.if !defined(_SKIP_BUILD)
# We need libutil.h, get it directly to avoid
# recording a build dependency
CFLAGS+= -I${SRCTOP}/lib/libutil
# Same issue with libm
MSUN_ARCH_SUBDIR != ${MAKE} -B -C ${SRCTOP}/lib/msun -V ARCH_SUBDIR
# unfortunately msun/src contains both private and public headers
CFLAGS+= -I${SRCTOP}/lib/msun/${MSUN_ARCH_SUBDIR}
.if ${MACHINE_CPUARCH} == "i386" || ${MACHINE_CPUARCH} == "amd64"
CFLAGS+= -I${SRCTOP}/lib/msun/x86
.endif
CFLAGS+= -I${SRCTOP}/lib/msun/src
# and we do not want to record a dependency on msun
.if ${.MAKE.LEVEL} > 0
GENDIRDEPS_FILTER+= N${RELDIR:H}/msun
.endif
.endif
# Disable warnings in contributed sources.
CWARNFLAGS:= ${.IMPSRC:Ngdtoa_*.c:C/^.+$/${CWARNFLAGS}/:C/^$/-w/}
# XXX For now, we don't allow libc to be compiled with
# -fstack-protector-all because it breaks rtld. We may want to make a librtld
# in the future to circumvent this.
SSP_CFLAGS:= ${SSP_CFLAGS:S/^-fstack-protector-all$/-fstack-protector/}
# Disable stack protection for SSP symbols.
SSP_CFLAGS:= ${.IMPSRC:N*/stack_protector.c:C/^.+$/${SSP_CFLAGS}/}
# Generate stack unwinding tables for cancellation points
CANCELPOINTS_CFLAGS:= ${.IMPSRC:Mcancelpoints_*:C/^.+$/${CANCELPOINTS_CFLAGS}/:C/^$//}