mirror_zfs/config/kernel-fpu.m4
Brian Behlendorf 608f8749a1
Perform KABI checks in parallel
Reduce the time required for ./configure to perform the needed
KABI checks by allowing kbuild to compile multiple test cases in
parallel.  This was accomplished by splitting each test's source
code from the logic handling whether that code could be compiled
or not.

By introducing this split it's possible to minimize the number of
times kbuild needs to be invoked.  As importantly, it means all of
the tests can be built in parallel.  This does require a little extra
care since we expect some tests to fail, so the --keep-going (-k)
option must be provided otherwise some tests may not get compiled.
Furthermore, since a failure during the kbuild modpost phase will
result in an early exit; the final linking phase is limited to tests
which passed the initial compilation and produced an object file.

Once everything has been built the configure script proceeds as
previously.  The only significant difference is that it now merely
needs to test for the existence of a .ko file to determine the
result of a given test.  This vastly speeds up the entire process.

New test cases should use ZFS_LINUX_TEST_SRC to declare their test
source code and ZFS_LINUX_TEST_RESULT to check the result.  All of
the existing kernel-*.m4 files have been updated accordingly, see
config/kernel-current-time.m4 for a basic example.  The legacy
ZFS_LINUX_TRY_COMPILE macro has been kept to handle special cases
but it's use is not encouraged.

                  master (secs)   patched (secs)
                  -------------   ----------------
autogen.sh        61              68
configure         137             24  (~17% of current run time)
make -j $(nproc)  44              44
make rpms         287             150

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8547 
Closes #9132
Closes #9341
2019-10-01 12:50:34 -07:00

130 lines
3.4 KiB
Plaintext

dnl #
dnl # Handle differences in kernel FPU code.
dnl #
dnl # Kernel
dnl # 5.2: The fpu->initialized flag was replaced by TIF_NEED_FPU_LOAD.
dnl # HAVE_KERNEL_TIF_NEED_FPU_LOAD
dnl #
dnl # 5.0: As an optimization SIMD operations performed by kernel
dnl # threads can skip saving and restoring their FPU context.
dnl # Wrappers have been introduced to determine the running
dnl # context and use either the SIMD or generic implementation.
dnl # This change was made to the 4.19.38 and 4.14.120 LTS kernels.
dnl # HAVE_KERNEL_FPU_INITIALIZED
dnl #
dnl # 4.2: Use __kernel_fpu_{begin,end}()
dnl # HAVE_UNDERSCORE_KERNEL_FPU & KERNEL_EXPORTS_X86_FPU
dnl #
dnl # Pre-4.2: Use kernel_fpu_{begin,end}()
dnl # HAVE_KERNEL_FPU & KERNEL_EXPORTS_X86_FPU
dnl #
dnl # N.B. The header check is performed before all other checks since it
dnl # depends on HAVE_KERNEL_FPU_API_HEADER being set in confdefs.h.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_FPU_HEADER], [
AC_MSG_CHECKING([whether fpu headers are available])
ZFS_LINUX_TRY_COMPILE([
#include <linux/module.h>
#include <asm/fpu/api.h>
],[
],[
AC_DEFINE(HAVE_KERNEL_FPU_API_HEADER, 1,
[kernel has asm/fpu/api.h])
AC_MSG_RESULT(asm/fpu/api.h)
],[
AC_MSG_RESULT(i387.h & xcr.h)
])
])
AC_DEFUN([ZFS_AC_KERNEL_SRC_FPU], [
ZFS_LINUX_TEST_SRC([kernel_fpu], [
#ifdef HAVE_KERNEL_FPU_API_HEADER
#include <asm/fpu/api.h>
#else
#include <asm/i387.h>
#include <asm/xcr.h>
#endif
], [
kernel_fpu_begin();
kernel_fpu_end();
], [], [$ZFS_META_LICENSE])
ZFS_LINUX_TEST_SRC([__kernel_fpu], [
#ifdef HAVE_KERNEL_FPU_API_HEADER
#include <asm/fpu/api.h>
#else
#include <asm/i387.h>
#include <asm/xcr.h>
#endif
], [
__kernel_fpu_begin();
__kernel_fpu_end();
], [], [$ZFS_META_LICENSE])
ZFS_LINUX_TEST_SRC([fpu_initialized], [
#include <linux/module.h>
#include <linux/sched.h>
],[
struct fpu *fpu = &current->thread.fpu;
if (fpu->initialized) { return (0); };
])
ZFS_LINUX_TEST_SRC([tif_need_fpu_load], [
#include <linux/module.h>
#include <asm/thread_info.h>
#if !defined(TIF_NEED_FPU_LOAD)
#error "TIF_NEED_FPU_LOAD undefined"
#endif
],[])
])
AC_DEFUN([ZFS_AC_KERNEL_FPU], [
dnl #
dnl # Legacy kernel
dnl #
AC_MSG_CHECKING([whether kernel fpu is available])
ZFS_LINUX_TEST_RESULT_SYMBOL([kernel_fpu_license],
[kernel_fpu_begin], [arch/x86/kernel/fpu/core.c], [
AC_MSG_RESULT(kernel_fpu_*)
AC_DEFINE(HAVE_KERNEL_FPU, 1,
[kernel has kernel_fpu_* functions])
AC_DEFINE(KERNEL_EXPORTS_X86_FPU, 1,
[kernel exports FPU functions])
],[
dnl #
dnl # Linux 4.2 kernel
dnl #
ZFS_LINUX_TEST_RESULT_SYMBOL([__kernel_fpu_license],
[__kernel_fpu_begin],
[arch/x86/kernel/fpu/core.c arch/x86/kernel/i387.c], [
AC_MSG_RESULT(__kernel_fpu_*)
AC_DEFINE(HAVE_UNDERSCORE_KERNEL_FPU, 1,
[kernel has __kernel_fpu_* functions])
AC_DEFINE(KERNEL_EXPORTS_X86_FPU, 1,
[kernel exports FPU functions])
],[
dnl #
dnl # Linux 5.0 kernel
dnl #
ZFS_LINUX_TEST_RESULT([fpu_initialized], [
AC_MSG_RESULT(fpu.initialized)
AC_DEFINE(HAVE_KERNEL_FPU_INITIALIZED, 1,
[kernel fpu.initialized exists])
],[
dnl #
dnl # Linux 5.2 kernel
dnl #
ZFS_LINUX_TEST_RESULT([tif_need_fpu_load], [
AC_MSG_RESULT(TIF_NEED_FPU_LOAD)
AC_DEFINE(
HAVE_KERNEL_TIF_NEED_FPU_LOAD, 1,
[kernel TIF_NEED_FPU_LOAD exists])
],[
AC_MSG_RESULT(unavailable)
])
])
])
])
])