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freebsd-nq/config/kernel-fpu.m4

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Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
dnl #
dnl # Handle differences in kernel FPU code.
Support for vectorized algorithms on x86 This is initial support for x86 vectorized implementations of ZFS parity and checksum algorithms. For the compilation phase, configure step checks if toolchain supports relevant instruction sets. Each implementation must ensure that the code is not passed to compiler if relevant instruction set is not supported. For this purpose, following new defines are provided if instruction set is supported: - HAVE_SSE, - HAVE_SSE2, - HAVE_SSE3, - HAVE_SSSE3, - HAVE_SSE4_1, - HAVE_SSE4_2, - HAVE_AVX, - HAVE_AVX2. For detecting if an instruction set can be used in runtime, following functions are provided in (include/linux/simd_x86.h): - zfs_sse_available() - zfs_sse2_available() - zfs_sse3_available() - zfs_ssse3_available() - zfs_sse4_1_available() - zfs_sse4_2_available() - zfs_avx_available() - zfs_avx2_available() - zfs_bmi1_available() - zfs_bmi2_available() These function should be called once, on module load, or initialization. They are safe to use from user and kernel space. If an implementation is using more than single instruction set, both compiler and runtime support for all relevant instruction sets should be checked. Kernel fpu methods: - kfpu_begin() - kfpu_end() Use __get_cpuid_max and __cpuid_count from <cpuid.h> Both gcc and clang have support for these. They also handle ebx register in case it is used for PIC code. Signed-off-by: Gvozden Neskovic <neskovic@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Closes #4381
2016-02-29 18:42:27 +00:00
dnl #
Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
dnl # Kernel
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
dnl # 5.0: Wrappers have been introduced to save/restore the FPU state.
Linux 5.0 compat: SIMD compatibility Restore the SIMD optimization for 4.19.38 LTS, 4.14.120 LTS, and 5.0 and newer kernels. This is accomplished by leveraging the fact that by definition dedicated kernel threads never need to concern themselves with saving and restoring the user FPU state. Therefore, they may use the FPU as long as we can guarantee user tasks always restore their FPU state before context switching back to user space. For the 5.0 and 5.1 kernels disabling preemption and local interrupts is sufficient to allow the FPU to be used. All non-kernel threads will restore the preserved user FPU state. For 5.2 and latter kernels the user FPU state restoration will be skipped if the kernel determines the registers have not changed. Therefore, for these kernels we need to perform the additional step of saving and restoring the FPU registers. Invalidating the per-cpu global tracking the FPU state would force a restore but that functionality is private to the core x86 FPU implementation and unavailable. In practice, restricting SIMD to kernel threads is not a major restriction for ZFS. The vast majority of SIMD operations are already performed by the IO pipeline. The remaining cases are relatively infrequent and can be handled by the generic code without significant impact. The two most noteworthy cases are: 1) Decrypting the wrapping key for an encrypted dataset, i.e. `zfs load-key`. All other encryption and decryption operations will use the SIMD optimized implementations. 2) Generating the payload checksums for a `zfs send` stream. In order to avoid making any changes to the higher layers of ZFS all of the `*_get_ops()` functions were updated to take in to consideration the calling context. This allows for the fastest implementation to be used as appropriate (see kfpu_allowed()). The only other notable instance of SIMD operations being used outside a kernel thread was at module load time. This code was moved in to a taskq in order to accommodate the new kernel thread restriction. Finally, a few other modifications were made in order to further harden this code and facilitate testing. They include updating each implementations operations structure to be declared as a constant. And allowing "cycle" to be set when selecting the preferred ops in the kernel as well as user space. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #8754 Closes #8793 Closes #8965
2019-07-12 16:31:20 +00:00
dnl # This change was made to the 4.19.38 and 4.14.120 LTS kernels.
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
dnl # HAVE_KERNEL_FPU_INTERNAL
Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
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
Support for vectorized algorithms on x86 This is initial support for x86 vectorized implementations of ZFS parity and checksum algorithms. For the compilation phase, configure step checks if toolchain supports relevant instruction sets. Each implementation must ensure that the code is not passed to compiler if relevant instruction set is not supported. For this purpose, following new defines are provided if instruction set is supported: - HAVE_SSE, - HAVE_SSE2, - HAVE_SSE3, - HAVE_SSSE3, - HAVE_SSE4_1, - HAVE_SSE4_2, - HAVE_AVX, - HAVE_AVX2. For detecting if an instruction set can be used in runtime, following functions are provided in (include/linux/simd_x86.h): - zfs_sse_available() - zfs_sse2_available() - zfs_sse3_available() - zfs_ssse3_available() - zfs_sse4_1_available() - zfs_sse4_2_available() - zfs_avx_available() - zfs_avx2_available() - zfs_bmi1_available() - zfs_bmi2_available() These function should be called once, on module load, or initialization. They are safe to use from user and kernel space. If an implementation is using more than single instruction set, both compiler and runtime support for all relevant instruction sets should be checked. Kernel fpu methods: - kfpu_begin() - kfpu_end() Use __get_cpuid_max and __cpuid_count from <cpuid.h> Both gcc and clang have support for these. They also handle ebx register in case it is used for PIC code. Signed-off-by: Gvozden Neskovic <neskovic@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Closes #4381
2016-02-29 18:42:27 +00:00
dnl #
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 19:50:34 +00:00
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])
Support for vectorized algorithms on x86 This is initial support for x86 vectorized implementations of ZFS parity and checksum algorithms. For the compilation phase, configure step checks if toolchain supports relevant instruction sets. Each implementation must ensure that the code is not passed to compiler if relevant instruction set is not supported. For this purpose, following new defines are provided if instruction set is supported: - HAVE_SSE, - HAVE_SSE2, - HAVE_SSE3, - HAVE_SSSE3, - HAVE_SSE4_1, - HAVE_SSE4_2, - HAVE_AVX, - HAVE_AVX2. For detecting if an instruction set can be used in runtime, following functions are provided in (include/linux/simd_x86.h): - zfs_sse_available() - zfs_sse2_available() - zfs_sse3_available() - zfs_ssse3_available() - zfs_sse4_1_available() - zfs_sse4_2_available() - zfs_avx_available() - zfs_avx2_available() - zfs_bmi1_available() - zfs_bmi2_available() These function should be called once, on module load, or initialization. They are safe to use from user and kernel space. If an implementation is using more than single instruction set, both compiler and runtime support for all relevant instruction sets should be checked. Kernel fpu methods: - kfpu_begin() - kfpu_end() Use __get_cpuid_max and __cpuid_count from <cpuid.h> Both gcc and clang have support for these. They also handle ebx register in case it is used for PIC code. Signed-off-by: Gvozden Neskovic <neskovic@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Closes #4381
2016-02-29 18:42:27 +00:00
ZFS_LINUX_TRY_COMPILE([
kernel_fpu fixes This patch fixes a few issues when detecting which kernel_fpu functions are available. - Use kernel_fpu_begin() if it's exported on newer kernels. - Use ZFS_LINUX_TRY_COMPILE_SYMBOL() to choose the right kernel_fpu function when using --enable-linux-builtin. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259 Closes #8363
2019-03-07 00:03:03 +00:00
#include <linux/module.h>
#include <asm/fpu/api.h>
],[
],[
Minor style cleanup Resolve an assortment of style inconsistencies including use of white space, typos, capitalization, and line wrapping. There is no functional change. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Reviewed-by: George Melikov <mail@gmelikov.ru> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #9030
2019-07-17 00:22:31 +00:00
AC_DEFINE(HAVE_KERNEL_FPU_API_HEADER, 1,
[kernel has asm/fpu/api.h])
kernel_fpu fixes This patch fixes a few issues when detecting which kernel_fpu functions are available. - Use kernel_fpu_begin() if it's exported on newer kernels. - Use ZFS_LINUX_TRY_COMPILE_SYMBOL() to choose the right kernel_fpu function when using --enable-linux-builtin. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259 Closes #8363
2019-03-07 00:03:03 +00:00
AC_MSG_RESULT(asm/fpu/api.h)
],[
AC_MSG_RESULT(i387.h & xcr.h)
])
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 19:50:34 +00:00
])
kernel_fpu fixes This patch fixes a few issues when detecting which kernel_fpu functions are available. - Use kernel_fpu_begin() if it's exported on newer kernels. - Use ZFS_LINUX_TRY_COMPILE_SYMBOL() to choose the right kernel_fpu function when using --enable-linux-builtin. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259 Closes #8363
2019-03-07 00:03:03 +00:00
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 19:50:34 +00:00
AC_DEFUN([ZFS_AC_KERNEL_SRC_FPU], [
ZFS_LINUX_TEST_SRC([kernel_fpu], [
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
#include <linux/types.h>
kernel_fpu fixes This patch fixes a few issues when detecting which kernel_fpu functions are available. - Use kernel_fpu_begin() if it's exported on newer kernels. - Use ZFS_LINUX_TRY_COMPILE_SYMBOL() to choose the right kernel_fpu function when using --enable-linux-builtin. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259 Closes #8363
2019-03-07 00:03:03 +00:00
#ifdef HAVE_KERNEL_FPU_API_HEADER
#include <asm/fpu/api.h>
#else
Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
#include <asm/i387.h>
#include <asm/xcr.h>
kernel_fpu fixes This patch fixes a few issues when detecting which kernel_fpu functions are available. - Use kernel_fpu_begin() if it's exported on newer kernels. - Use ZFS_LINUX_TRY_COMPILE_SYMBOL() to choose the right kernel_fpu function when using --enable-linux-builtin. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259 Closes #8363
2019-03-07 00:03:03 +00:00
#endif
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 19:50:34 +00:00
], [
Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
kernel_fpu_begin();
kernel_fpu_end();
Linux 5.11 compat: conftest Update the ZFS_LINUX_TEST_PROGRAM macro to always set the module license. As of the 5.11 kernel not setting a license has been converted from a warning to an error. Reviewed-by: Rafael Kitover <rkitover@gmail.com> Reviewed-by: Coleman Kane <ckane@colemankane.org> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #11387 Closes #11390
2020-12-23 19:40:02 +00:00
], [], [ZFS_META_LICENSE])
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 19:50:34 +00:00
ZFS_LINUX_TEST_SRC([__kernel_fpu], [
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
#include <linux/types.h>
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 19:50:34 +00:00
#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();
Linux 5.11 compat: conftest Update the ZFS_LINUX_TEST_PROGRAM macro to always set the module license. As of the 5.11 kernel not setting a license has been converted from a warning to an error. Reviewed-by: Rafael Kitover <rkitover@gmail.com> Reviewed-by: Coleman Kane <ckane@colemankane.org> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #11387 Closes #11390
2020-12-23 19:40:02 +00:00
], [], [ZFS_META_LICENSE])
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 19:50:34 +00:00
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
ZFS_LINUX_TEST_SRC([fpu_internal], [
#if defined(__x86_64) || defined(__x86_64__) || \
defined(__i386) || defined(__i386__)
#if !defined(__x86)
#define __x86
#endif
#endif
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 19:50:34 +00:00
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
#if !defined(__x86)
#error Unsupported architecture
#endif
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 19:50:34 +00:00
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
#include <linux/types.h>
#ifdef HAVE_KERNEL_FPU_API_HEADER
#include <asm/fpu/api.h>
#include <asm/fpu/internal.h>
#else
#include <asm/i387.h>
#include <asm/xcr.h>
#endif
#if !defined(XSTATE_XSAVE)
#error XSTATE_XSAVE not defined
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 19:50:34 +00:00
#endif
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
#if !defined(XSTATE_XRESTORE)
#error XSTATE_XRESTORE not defined
#endif
],[
struct fpu *fpu = &current->thread.fpu;
union fpregs_state *st = &fpu->state;
struct fregs_state *fr __attribute__ ((unused)) = &st->fsave;
struct fxregs_state *fxr __attribute__ ((unused)) = &st->fxsave;
struct xregs_state *xr __attribute__ ((unused)) = &st->xsave;
])
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 19:50:34 +00:00
])
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], [
Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
AC_MSG_RESULT(kernel_fpu_*)
Minor style cleanup Resolve an assortment of style inconsistencies including use of white space, typos, capitalization, and line wrapping. There is no functional change. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Reviewed-by: George Melikov <mail@gmelikov.ru> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #9030
2019-07-17 00:22:31 +00:00
AC_DEFINE(HAVE_KERNEL_FPU, 1,
[kernel has kernel_fpu_* functions])
AC_DEFINE(KERNEL_EXPORTS_X86_FPU, 1,
[kernel exports FPU functions])
Support for vectorized algorithms on x86 This is initial support for x86 vectorized implementations of ZFS parity and checksum algorithms. For the compilation phase, configure step checks if toolchain supports relevant instruction sets. Each implementation must ensure that the code is not passed to compiler if relevant instruction set is not supported. For this purpose, following new defines are provided if instruction set is supported: - HAVE_SSE, - HAVE_SSE2, - HAVE_SSE3, - HAVE_SSSE3, - HAVE_SSE4_1, - HAVE_SSE4_2, - HAVE_AVX, - HAVE_AVX2. For detecting if an instruction set can be used in runtime, following functions are provided in (include/linux/simd_x86.h): - zfs_sse_available() - zfs_sse2_available() - zfs_sse3_available() - zfs_ssse3_available() - zfs_sse4_1_available() - zfs_sse4_2_available() - zfs_avx_available() - zfs_avx2_available() - zfs_bmi1_available() - zfs_bmi2_available() These function should be called once, on module load, or initialization. They are safe to use from user and kernel space. If an implementation is using more than single instruction set, both compiler and runtime support for all relevant instruction sets should be checked. Kernel fpu methods: - kfpu_begin() - kfpu_end() Use __get_cpuid_max and __cpuid_count from <cpuid.h> Both gcc and clang have support for these. They also handle ebx register in case it is used for PIC code. Signed-off-by: Gvozden Neskovic <neskovic@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Closes #4381
2016-02-29 18:42:27 +00:00
],[
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 19:50:34 +00:00
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], [
Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
AC_MSG_RESULT(__kernel_fpu_*)
Linux 5.0 compat: SIMD compatibility Restore the SIMD optimization for 4.19.38 LTS, 4.14.120 LTS, and 5.0 and newer kernels. This is accomplished by leveraging the fact that by definition dedicated kernel threads never need to concern themselves with saving and restoring the user FPU state. Therefore, they may use the FPU as long as we can guarantee user tasks always restore their FPU state before context switching back to user space. For the 5.0 and 5.1 kernels disabling preemption and local interrupts is sufficient to allow the FPU to be used. All non-kernel threads will restore the preserved user FPU state. For 5.2 and latter kernels the user FPU state restoration will be skipped if the kernel determines the registers have not changed. Therefore, for these kernels we need to perform the additional step of saving and restoring the FPU registers. Invalidating the per-cpu global tracking the FPU state would force a restore but that functionality is private to the core x86 FPU implementation and unavailable. In practice, restricting SIMD to kernel threads is not a major restriction for ZFS. The vast majority of SIMD operations are already performed by the IO pipeline. The remaining cases are relatively infrequent and can be handled by the generic code without significant impact. The two most noteworthy cases are: 1) Decrypting the wrapping key for an encrypted dataset, i.e. `zfs load-key`. All other encryption and decryption operations will use the SIMD optimized implementations. 2) Generating the payload checksums for a `zfs send` stream. In order to avoid making any changes to the higher layers of ZFS all of the `*_get_ops()` functions were updated to take in to consideration the calling context. This allows for the fastest implementation to be used as appropriate (see kfpu_allowed()). The only other notable instance of SIMD operations being used outside a kernel thread was at module load time. This code was moved in to a taskq in order to accommodate the new kernel thread restriction. Finally, a few other modifications were made in order to further harden this code and facilitate testing. They include updating each implementations operations structure to be declared as a constant. And allowing "cycle" to be set when selecting the preferred ops in the kernel as well as user space. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #8754 Closes #8793 Closes #8965
2019-07-12 16:31:20 +00:00
AC_DEFINE(HAVE_UNDERSCORE_KERNEL_FPU, 1,
[kernel has __kernel_fpu_* functions])
AC_DEFINE(KERNEL_EXPORTS_X86_FPU, 1,
[kernel exports FPU functions])
Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
],[
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
ZFS_LINUX_TEST_RESULT([fpu_internal], [
AC_MSG_RESULT(internal)
AC_DEFINE(HAVE_KERNEL_FPU_INTERNAL, 1,
[kernel fpu internal])
Linux 5.0 compat: SIMD compatibility Restore the SIMD optimization for 4.19.38 LTS, 4.14.120 LTS, and 5.0 and newer kernels. This is accomplished by leveraging the fact that by definition dedicated kernel threads never need to concern themselves with saving and restoring the user FPU state. Therefore, they may use the FPU as long as we can guarantee user tasks always restore their FPU state before context switching back to user space. For the 5.0 and 5.1 kernels disabling preemption and local interrupts is sufficient to allow the FPU to be used. All non-kernel threads will restore the preserved user FPU state. For 5.2 and latter kernels the user FPU state restoration will be skipped if the kernel determines the registers have not changed. Therefore, for these kernels we need to perform the additional step of saving and restoring the FPU registers. Invalidating the per-cpu global tracking the FPU state would force a restore but that functionality is private to the core x86 FPU implementation and unavailable. In practice, restricting SIMD to kernel threads is not a major restriction for ZFS. The vast majority of SIMD operations are already performed by the IO pipeline. The remaining cases are relatively infrequent and can be handled by the generic code without significant impact. The two most noteworthy cases are: 1) Decrypting the wrapping key for an encrypted dataset, i.e. `zfs load-key`. All other encryption and decryption operations will use the SIMD optimized implementations. 2) Generating the payload checksums for a `zfs send` stream. In order to avoid making any changes to the higher layers of ZFS all of the `*_get_ops()` functions were updated to take in to consideration the calling context. This allows for the fastest implementation to be used as appropriate (see kfpu_allowed()). The only other notable instance of SIMD operations being used outside a kernel thread was at module load time. This code was moved in to a taskq in order to accommodate the new kernel thread restriction. Finally, a few other modifications were made in order to further harden this code and facilitate testing. They include updating each implementations operations structure to be declared as a constant. And allowing "cycle" to be set when selecting the preferred ops in the kernel as well as user space. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #8754 Closes #8793 Closes #8965
2019-07-12 16:31:20 +00:00
],[
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore Contrary to initial testing we cannot rely on these kernels to invalidate the per-cpu FPU state and restore the FPU registers. Nor can we guarantee that the kernel won't modify the FPU state which we saved in the task struck. Therefore, the kfpu_begin() and kfpu_end() functions have been updated to save and restore the FPU state using our own dedicated per-cpu FPU state variables. This has the additional advantage of allowing us to use the FPU again in user threads. So we remove the code which was added to use task queues to ensure some functions ran in kernel threads. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #9346 Closes #9403
2019-10-24 17:17:33 +00:00
AC_MSG_RESULT(unavailable)
Linux 5.0 compat: SIMD compatibility Restore the SIMD optimization for 4.19.38 LTS, 4.14.120 LTS, and 5.0 and newer kernels. This is accomplished by leveraging the fact that by definition dedicated kernel threads never need to concern themselves with saving and restoring the user FPU state. Therefore, they may use the FPU as long as we can guarantee user tasks always restore their FPU state before context switching back to user space. For the 5.0 and 5.1 kernels disabling preemption and local interrupts is sufficient to allow the FPU to be used. All non-kernel threads will restore the preserved user FPU state. For 5.2 and latter kernels the user FPU state restoration will be skipped if the kernel determines the registers have not changed. Therefore, for these kernels we need to perform the additional step of saving and restoring the FPU registers. Invalidating the per-cpu global tracking the FPU state would force a restore but that functionality is private to the core x86 FPU implementation and unavailable. In practice, restricting SIMD to kernel threads is not a major restriction for ZFS. The vast majority of SIMD operations are already performed by the IO pipeline. The remaining cases are relatively infrequent and can be handled by the generic code without significant impact. The two most noteworthy cases are: 1) Decrypting the wrapping key for an encrypted dataset, i.e. `zfs load-key`. All other encryption and decryption operations will use the SIMD optimized implementations. 2) Generating the payload checksums for a `zfs send` stream. In order to avoid making any changes to the higher layers of ZFS all of the `*_get_ops()` functions were updated to take in to consideration the calling context. This allows for the fastest implementation to be used as appropriate (see kfpu_allowed()). The only other notable instance of SIMD operations being used outside a kernel thread was at module load time. This code was moved in to a taskq in order to accommodate the new kernel thread restriction. Finally, a few other modifications were made in order to further harden this code and facilitate testing. They include updating each implementations operations structure to be declared as a constant. And allowing "cycle" to be set when selecting the preferred ops in the kernel as well as user space. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #8754 Closes #8793 Closes #8965
2019-07-12 16:31:20 +00:00
])
Linux 5.0 compat: Disable vector instructions on 5.0+ kernels The 5.0 kernel no longer exports the functions we need to do vector (SSE/SSE2/SSE3/AVX...) instructions. Disable vector-based checksum algorithms when building against those kernels. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #8259
2019-01-12 02:01:28 +00:00
])
Support for vectorized algorithms on x86 This is initial support for x86 vectorized implementations of ZFS parity and checksum algorithms. For the compilation phase, configure step checks if toolchain supports relevant instruction sets. Each implementation must ensure that the code is not passed to compiler if relevant instruction set is not supported. For this purpose, following new defines are provided if instruction set is supported: - HAVE_SSE, - HAVE_SSE2, - HAVE_SSE3, - HAVE_SSSE3, - HAVE_SSE4_1, - HAVE_SSE4_2, - HAVE_AVX, - HAVE_AVX2. For detecting if an instruction set can be used in runtime, following functions are provided in (include/linux/simd_x86.h): - zfs_sse_available() - zfs_sse2_available() - zfs_sse3_available() - zfs_ssse3_available() - zfs_sse4_1_available() - zfs_sse4_2_available() - zfs_avx_available() - zfs_avx2_available() - zfs_bmi1_available() - zfs_bmi2_available() These function should be called once, on module load, or initialization. They are safe to use from user and kernel space. If an implementation is using more than single instruction set, both compiler and runtime support for all relevant instruction sets should be checked. Kernel fpu methods: - kfpu_begin() - kfpu_end() Use __get_cpuid_max and __cpuid_count from <cpuid.h> Both gcc and clang have support for these. They also handle ebx register in case it is used for PIC code. Signed-off-by: Gvozden Neskovic <neskovic@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Closes #4381
2016-02-29 18:42:27 +00:00
])
])
Reference in New Issue Copy Permalink