diff options
Diffstat (limited to 'module')
| -rw-r--r-- | module/zcommon/Makefile.in | 2 | ||||
| -rw-r--r-- | module/zcommon/zfs_fletcher.c | 311 | ||||
| -rw-r--r-- | module/zcommon/zfs_fletcher_intel.c | 148 | ||||
| -rw-r--r-- | module/zcommon/zfs_prop.c | 3 |
4 files changed, 428 insertions, 36 deletions
diff --git a/module/zcommon/Makefile.in b/module/zcommon/Makefile.in index 67e474ee0..0882fac2d 100644 --- a/module/zcommon/Makefile.in +++ b/module/zcommon/Makefile.in @@ -15,3 +15,5 @@ $(MODULE)-objs += zfs_comutil.o $(MODULE)-objs += zfs_fletcher.o $(MODULE)-objs += zfs_uio.o $(MODULE)-objs += zpool_prop.o + +$(MODULE)-$(CONFIG_X86) += zfs_fletcher_intel.o diff --git a/module/zcommon/zfs_fletcher.c b/module/zcommon/zfs_fletcher.c index edd0cbe6c..2c2d01d5c 100644 --- a/module/zcommon/zfs_fletcher.c +++ b/module/zcommon/zfs_fletcher.c @@ -128,8 +128,60 @@ #include <sys/types.h> #include <sys/sysmacros.h> #include <sys/byteorder.h> -#include <sys/zio.h> #include <sys/spa.h> +#include <sys/zfs_context.h> +#include <zfs_fletcher.h> + +static void fletcher_4_scalar_init(zio_cksum_t *zcp); +static void fletcher_4_scalar(const void *buf, uint64_t size, + zio_cksum_t *zcp); +static void fletcher_4_scalar_byteswap(const void *buf, uint64_t size, + zio_cksum_t *zcp); +static boolean_t fletcher_4_scalar_valid(void); + +static const fletcher_4_ops_t fletcher_4_scalar_ops = { + .init = fletcher_4_scalar_init, + .compute = fletcher_4_scalar, + .compute_byteswap = fletcher_4_scalar_byteswap, + .valid = fletcher_4_scalar_valid, + .name = "scalar" +}; + +static const fletcher_4_ops_t *fletcher_4_algos[] = { + &fletcher_4_scalar_ops, +#if defined(HAVE_AVX) && defined(HAVE_AVX2) + &fletcher_4_avx2_ops, +#endif +}; + +static enum fletcher_selector { + FLETCHER_FASTEST = 0, + FLETCHER_SCALAR, +#if defined(HAVE_AVX) && defined(HAVE_AVX2) + FLETCHER_AVX2, +#endif + FLETCHER_CYCLE +} fletcher_4_impl_chosen = FLETCHER_SCALAR; + +static struct fletcher_4_impl_selector { + const char *fis_name; + const fletcher_4_ops_t *fis_ops; +} fletcher_4_impl_selectors[] = { + [ FLETCHER_FASTEST ] = { "fastest", NULL }, + [ FLETCHER_SCALAR ] = { "scalar", &fletcher_4_scalar_ops }, +#if defined(HAVE_AVX) && defined(HAVE_AVX2) + [ FLETCHER_AVX2 ] = { "avx2", &fletcher_4_avx2_ops }, +#endif +#if !defined(_KERNEL) + [ FLETCHER_CYCLE ] = { "cycle", &fletcher_4_scalar_ops } +#endif +}; + +static kmutex_t fletcher_4_impl_lock; + +static kstat_t *fletcher_4_kstat; + +static kstat_named_t fletcher_4_kstat_data[ARRAY_SIZE(fletcher_4_algos)]; void fletcher_2_native(const void *buf, uint64_t size, zio_cksum_t *zcp) @@ -165,32 +217,25 @@ fletcher_2_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp) ZIO_SET_CHECKSUM(zcp, a0, a1, b0, b1); } -void -fletcher_4_native(const void *buf, uint64_t size, zio_cksum_t *zcp) +static void fletcher_4_scalar_init(zio_cksum_t *zcp) { - const uint32_t *ip = buf; - const uint32_t *ipend = ip + (size / sizeof (uint32_t)); - uint64_t a, b, c, d; - - for (a = b = c = d = 0; ip < ipend; ip++) { - a += ip[0]; - b += a; - c += b; - d += c; - } - - ZIO_SET_CHECKSUM(zcp, a, b, c, d); + ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0); } -void -fletcher_4_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp) +static void +fletcher_4_scalar(const void *buf, uint64_t size, zio_cksum_t *zcp) { const uint32_t *ip = buf; const uint32_t *ipend = ip + (size / sizeof (uint32_t)); uint64_t a, b, c, d; - for (a = b = c = d = 0; ip < ipend; ip++) { - a += BSWAP_32(ip[0]); + a = zcp->zc_word[0]; + b = zcp->zc_word[1]; + c = zcp->zc_word[2]; + d = zcp->zc_word[3]; + + for (; ip < ipend; ip++) { + a += ip[0]; b += a; c += b; d += c; @@ -199,9 +244,8 @@ fletcher_4_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp) ZIO_SET_CHECKSUM(zcp, a, b, c, d); } -void -fletcher_4_incremental_native(const void *buf, uint64_t size, - zio_cksum_t *zcp) +static void +fletcher_4_scalar_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp) { const uint32_t *ip = buf; const uint32_t *ipend = ip + (size / sizeof (uint32_t)); @@ -213,7 +257,7 @@ fletcher_4_incremental_native(const void *buf, uint64_t size, d = zcp->zc_word[3]; for (; ip < ipend; ip++) { - a += ip[0]; + a += BSWAP_32(ip[0]); b += a; c += b; d += c; @@ -222,30 +266,225 @@ fletcher_4_incremental_native(const void *buf, uint64_t size, ZIO_SET_CHECKSUM(zcp, a, b, c, d); } +static boolean_t +fletcher_4_scalar_valid(void) +{ + return (B_TRUE); +} + +int +fletcher_4_impl_set(const char *val) +{ + const fletcher_4_ops_t *ops; + enum fletcher_selector idx; + size_t val_len; + unsigned i; + + val_len = strlen(val); + while ((val_len > 0) && !!isspace(val[val_len-1])) /* trim '\n' */ + val_len--; + + for (i = 0; i < ARRAY_SIZE(fletcher_4_impl_selectors); i++) { + const char *name = fletcher_4_impl_selectors[i].fis_name; + + if (val_len == strlen(name) && + strncmp(val, name, val_len) == 0) { + idx = i; + break; + } + } + if (i >= ARRAY_SIZE(fletcher_4_impl_selectors)) + return (-EINVAL); + + ops = fletcher_4_impl_selectors[idx].fis_ops; + if (ops == NULL || !ops->valid()) + return (-ENOTSUP); + + mutex_enter(&fletcher_4_impl_lock); + if (fletcher_4_impl_chosen != idx) + fletcher_4_impl_chosen = idx; + mutex_exit(&fletcher_4_impl_lock); + + return (0); +} + +static inline const fletcher_4_ops_t * +fletcher_4_impl_get(void) +{ +#if !defined(_KERNEL) + if (fletcher_4_impl_chosen == FLETCHER_CYCLE) { + static volatile unsigned int cycle_count = 0; + const fletcher_4_ops_t *ops = NULL; + unsigned int index; + + while (1) { + index = atomic_inc_uint_nv(&cycle_count); + ops = fletcher_4_algos[ + index % ARRAY_SIZE(fletcher_4_algos)]; + if (ops->valid()) + break; + } + return (ops); + } +#endif + membar_producer(); + return (fletcher_4_impl_selectors[fletcher_4_impl_chosen].fis_ops); +} + +void +fletcher_4_native(const void *buf, uint64_t size, zio_cksum_t *zcp) +{ + const fletcher_4_ops_t *ops = fletcher_4_impl_get(); + + ops->init(zcp); + ops->compute(buf, size, zcp); + if (ops->fini != NULL) + ops->fini(zcp); +} + +void +fletcher_4_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp) +{ + const fletcher_4_ops_t *ops = fletcher_4_impl_get(); + + ops->init(zcp); + ops->compute_byteswap(buf, size, zcp); + if (ops->fini != NULL) + ops->fini(zcp); +} + +void +fletcher_4_incremental_native(const void *buf, uint64_t size, + zio_cksum_t *zcp) +{ + fletcher_4_scalar(buf, size, zcp); +} + void fletcher_4_incremental_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp) { - const uint32_t *ip = buf; - const uint32_t *ipend = ip + (size / sizeof (uint32_t)); - uint64_t a, b, c, d; + fletcher_4_scalar_byteswap(buf, size, zcp); +} - a = zcp->zc_word[0]; - b = zcp->zc_word[1]; - c = zcp->zc_word[2]; - d = zcp->zc_word[3]; +void +fletcher_4_init(void) +{ + const uint64_t const bench_ns = (50 * MICROSEC); /* 50ms */ + unsigned long best_run_count = 0; + unsigned long best_run_index = 0; + const unsigned data_size = 4096; + char *databuf; + int i; - for (; ip < ipend; ip++) { - a += BSWAP_32(ip[0]); - b += a; - c += b; - d += c; + databuf = kmem_alloc(data_size, KM_SLEEP); + for (i = 0; i < ARRAY_SIZE(fletcher_4_algos); i++) { + const fletcher_4_ops_t *ops = fletcher_4_algos[i]; + kstat_named_t *stat = &fletcher_4_kstat_data[i]; + unsigned long run_count = 0; + hrtime_t start; + zio_cksum_t zc; + + strncpy(stat->name, ops->name, sizeof (stat->name) - 1); + stat->data_type = KSTAT_DATA_UINT64; + stat->value.ui64 = 0; + + if (!ops->valid()) + continue; + + kpreempt_disable(); + start = gethrtime(); + ops->init(&zc); + do { + ops->compute(databuf, data_size, &zc); + run_count++; + } while (gethrtime() < start + bench_ns); + if (ops->fini != NULL) + ops->fini(&zc); + kpreempt_enable(); + + if (run_count > best_run_count) { + best_run_count = run_count; + best_run_index = i; + } + + /* + * Due to high overhead of gethrtime(), the performance data + * here is inaccurate and much slower than it could be. + * It's fine for our use though because only relative speed + * is important. + */ + stat->value.ui64 = data_size * run_count * + (NANOSEC / bench_ns) >> 20; /* by MB/s */ } + kmem_free(databuf, data_size); - ZIO_SET_CHECKSUM(zcp, a, b, c, d); + fletcher_4_impl_selectors[FLETCHER_FASTEST].fis_ops = + fletcher_4_algos[best_run_index]; + + mutex_init(&fletcher_4_impl_lock, NULL, MUTEX_DEFAULT, NULL); + fletcher_4_impl_set("fastest"); + + fletcher_4_kstat = kstat_create("zfs", 0, "fletcher_4_bench", + "misc", KSTAT_TYPE_NAMED, ARRAY_SIZE(fletcher_4_algos), + KSTAT_FLAG_VIRTUAL); + if (fletcher_4_kstat != NULL) { + fletcher_4_kstat->ks_data = fletcher_4_kstat_data; + kstat_install(fletcher_4_kstat); + } +} + +void +fletcher_4_fini(void) +{ + mutex_destroy(&fletcher_4_impl_lock); + if (fletcher_4_kstat != NULL) { + kstat_delete(fletcher_4_kstat); + fletcher_4_kstat = NULL; + } } #if defined(_KERNEL) && defined(HAVE_SPL) + +static int +fletcher_4_param_get(char *buffer, struct kernel_param *unused) +{ + int i, cnt = 0; + + for (i = 0; i < ARRAY_SIZE(fletcher_4_impl_selectors); i++) { + const fletcher_4_ops_t *ops; + + ops = fletcher_4_impl_selectors[i].fis_ops; + if (!ops->valid()) + continue; + + cnt += sprintf(buffer + cnt, + fletcher_4_impl_chosen == i ? "[%s] " : "%s ", + fletcher_4_impl_selectors[i].fis_name); + } + + return (cnt); +} + +static int +fletcher_4_param_set(const char *val, struct kernel_param *unused) +{ + return (fletcher_4_impl_set(val)); +} + +/* + * Choose a fletcher 4 implementation in ZFS. + * Users can choose the "fastest" algorithm, or "scalar" and "avx2" which means + * to compute fletcher 4 by CPU or vector instructions respectively. + * Users can also choose "cycle" to exercise all implementions, but this is + * for testing purpose therefore it can only be set in user space. + */ +module_param_call(zfs_fletcher_4_impl, + fletcher_4_param_set, fletcher_4_param_get, NULL, 0644); +MODULE_PARM_DESC(zfs_fletcher_4_impl, "Select fletcher 4 algorithm"); + +EXPORT_SYMBOL(fletcher_4_init); +EXPORT_SYMBOL(fletcher_4_fini); EXPORT_SYMBOL(fletcher_2_native); EXPORT_SYMBOL(fletcher_2_byteswap); EXPORT_SYMBOL(fletcher_4_native); diff --git a/module/zcommon/zfs_fletcher_intel.c b/module/zcommon/zfs_fletcher_intel.c new file mode 100644 index 000000000..38a40e234 --- /dev/null +++ b/module/zcommon/zfs_fletcher_intel.c @@ -0,0 +1,148 @@ +/* + * Implement fast Fletcher4 with AVX2 instructions. (x86_64) + * + * Use the 256-bit AVX2 SIMD instructions and registers to compute + * Fletcher4 in four incremental 64-bit parallel accumulator streams, + * and then combine the streams to form the final four checksum words. + * + * Copyright (C) 2015 Intel Corporation. + * + * Authors: + * James Guilford <[email protected]> + * Jinshan Xiong <[email protected]> + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if defined(HAVE_AVX) && defined(HAVE_AVX2) + +#include <linux/simd_x86.h> +#include <sys/spa_checksum.h> +#include <zfs_fletcher.h> + +static void +fletcher_4_avx2_init(zio_cksum_t *zcp) +{ + kfpu_begin(); + + /* clear avx2 registers */ + asm volatile("vpxor %ymm0, %ymm0, %ymm0"); + asm volatile("vpxor %ymm1, %ymm1, %ymm1"); + asm volatile("vpxor %ymm2, %ymm2, %ymm2"); + asm volatile("vpxor %ymm3, %ymm3, %ymm3"); +} + +static void +fletcher_4_avx2_fini(zio_cksum_t *zcp) +{ + uint64_t __attribute__((aligned(32))) a[4]; + uint64_t __attribute__((aligned(32))) b[4]; + uint64_t __attribute__((aligned(32))) c[4]; + uint64_t __attribute__((aligned(32))) d[4]; + uint64_t A, B, C, D; + + asm volatile("vmovdqu %%ymm0, %0":"=m" (a)); + asm volatile("vmovdqu %%ymm1, %0":"=m" (b)); + asm volatile("vmovdqu %%ymm2, %0":"=m" (c)); + asm volatile("vmovdqu %%ymm3, %0":"=m" (d)); + asm volatile("vzeroupper"); + + kfpu_end(); + + A = a[0] + a[1] + a[2] + a[3]; + B = 0 - a[1] - 2*a[2] - 3*a[3] + + 4*b[0] + 4*b[1] + 4*b[2] + 4*b[3]; + + C = a[2] + 3*a[3] + - 6*b[0] - 10*b[1] - 14*b[2] - 18*b[3] + + 16*c[0] + 16*c[1] + 16*c[2] + 16*c[3]; + + D = 0 - a[3] + + 4*b[0] + 10*b[1] + 20*b[2] + 34*b[3] + - 48*c[0] - 64*c[1] - 80*c[2] - 96*c[3] + + 64*d[0] + 64*d[1] + 64*d[2] + 64*d[3]; + + ZIO_SET_CHECKSUM(zcp, A, B, C, D); +} + +static void +fletcher_4_avx2(const void *buf, uint64_t size, zio_cksum_t *unused) +{ + const uint64_t *ip = buf; + const uint64_t *ipend = (uint64_t *)((uint8_t *)ip + size); + + for (; ip < ipend; ip += 2) { + asm volatile("vpmovzxdq %0, %%ymm4"::"m" (*ip)); + asm volatile("vpaddq %ymm4, %ymm0, %ymm0"); + asm volatile("vpaddq %ymm0, %ymm1, %ymm1"); + asm volatile("vpaddq %ymm1, %ymm2, %ymm2"); + asm volatile("vpaddq %ymm2, %ymm3, %ymm3"); + } +} + +static void +fletcher_4_avx2_byteswap(const void *buf, uint64_t size, zio_cksum_t *unused) +{ + static const struct { + uint64_t v[4] __attribute__((aligned(32))); + } mask = { + .v = { 0xFFFFFFFF00010203, 0xFFFFFFFF08090A0B, + 0xFFFFFFFF00010203, 0xFFFFFFFF08090A0B } + }; + const uint64_t *ip = buf; + const uint64_t *ipend = (uint64_t *)((uint8_t *)ip + size); + + asm volatile("vmovdqa %0, %%ymm5"::"m"(mask)); + + for (; ip < ipend; ip += 2) { + asm volatile("vpmovzxdq %0, %%ymm4"::"m" (*ip)); + asm volatile("vpshufb %ymm5, %ymm4, %ymm4"); + + asm volatile("vpaddq %ymm4, %ymm0, %ymm0"); + asm volatile("vpaddq %ymm0, %ymm1, %ymm1"); + asm volatile("vpaddq %ymm1, %ymm2, %ymm2"); + asm volatile("vpaddq %ymm2, %ymm3, %ymm3"); + } +} + +static boolean_t fletcher_4_avx2_valid(void) +{ + return (zfs_avx_available() && zfs_avx2_available()); +} + +const fletcher_4_ops_t fletcher_4_avx2_ops = { + .init = fletcher_4_avx2_init, + .fini = fletcher_4_avx2_fini, + .compute = fletcher_4_avx2, + .compute_byteswap = fletcher_4_avx2_byteswap, + .valid = fletcher_4_avx2_valid, + .name = "avx2" +}; + +#endif /* defined(HAVE_AVX) && defined(HAVE_AVX2) */ diff --git a/module/zcommon/zfs_prop.c b/module/zcommon/zfs_prop.c index 5a88cbe6c..76d564b43 100644 --- a/module/zcommon/zfs_prop.c +++ b/module/zcommon/zfs_prop.c @@ -35,6 +35,7 @@ #include "zfs_prop.h" #include "zfs_deleg.h" +#include "zfs_fletcher.h" #if defined(_KERNEL) #include <sys/systm.h> @@ -695,12 +696,14 @@ zfs_prop_align_right(zfs_prop_t prop) static int __init zcommon_init(void) { + fletcher_4_init(); return (0); } static void __exit zcommon_fini(void) { + fletcher_4_fini(); } module_init(zcommon_init); |