Hi Pavan, Same ask as for the first patch: -Do not change existing code in rte_reciprocal.[hc]: no _u32 suffix, please -Do not add lots of CR+LF to existing code
> -----Original Message----- > From: Pavan Nikhilesh [mailto:pbhagavat...@caviumnetworks.com] > Sent: Wednesday, September 6, 2017 11:22 AM > To: Dumitrescu, Cristian <cristian.dumitre...@intel.com>; > step...@networkplumber.org > Cc: dev@dpdk.org; Pavan Bhagavatula > <pbhagavat...@caviumnetworks.com> > Subject: [dpdk-dev] [PATCH v6 2/3] eal: add u64 bit variant for reciprocal > > From: Pavan Bhagavatula <pbhagavat...@caviumnetworks.com> > > Currently, rte_reciprocal only supports unsigned 32bit divisors. This > commit adds support for unsigned 64bit divisors. > > Rename unsigned 32bit specific functions appropriately and update > librte_sched accordingly. > > Signed-off-by: Pavan Nikhilesh <pbhagavat...@caviumnetworks.com> > --- > lib/librte_eal/bsdapp/eal/rte_eal_version.map | 3 +- > lib/librte_eal/common/include/rte_reciprocal.h | 109 > ++++++++++++++++++++-- > lib/librte_eal/common/rte_reciprocal.c | 116 > +++++++++++++++++++++--- > lib/librte_eal/linuxapp/eal/rte_eal_version.map | 3 +- > lib/librte_sched/Makefile | 4 +- > lib/librte_sched/rte_sched.c | 9 +- > 6 files changed, 219 insertions(+), 25 deletions(-) > > diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map > b/lib/librte_eal/bsdapp/eal/rte_eal_version.map > index 90d7258..59a85bb 100644 > --- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map > +++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map > @@ -241,6 +241,7 @@ EXPERIMENTAL { > DPDK_17.11 { > global: > > - rte_reciprocal_value; > + rte_reciprocal_value_u32; > + rte_reciprocal_value_u64; > > } DPDK_17.08; > diff --git a/lib/librte_eal/common/include/rte_reciprocal.h > b/lib/librte_eal/common/include/rte_reciprocal.h > index b6d752f..85599e6 100644 > --- a/lib/librte_eal/common/include/rte_reciprocal.h > +++ b/lib/librte_eal/common/include/rte_reciprocal.h > @@ -22,22 +22,117 @@ > #ifndef _RTE_RECIPROCAL_H_ > #define _RTE_RECIPROCAL_H_ > > -#include <stdint.h> > +#include <rte_memory.h> > > -struct rte_reciprocal { > +/** > + * Unsigned 32-bit divisor structure. > + */ > +struct rte_reciprocal_u32 { > uint32_t m; > uint8_t sh1, sh2; > }; > Do not add _32 suffix for exiting function, no name change, please. > +/** > + * Unsigned 64-bit divisor structure. > + */ > +struct rte_reciprocal_u64 { > + uint64_t m; > + uint8_t sh1; > +}; > + I am OK with adding +64 suffix for new API. > +/** > + * Divide given unsigned 32-bit integer with pre calculated divisor. > + * > + * @param a > + * The 32-bit dividend. > + * @param R > + * The pointer to pre calculated divisor reciprocal structure. > + * > + * @return > + * The result of the division > + */ > static inline uint32_t > -rte_reciprocal_divide(uint32_t a, struct rte_reciprocal R) > +rte_reciprocal_divide_u32(uint32_t a, struct rte_reciprocal_u32 *R) > { > - uint32_t t = (uint32_t)(((uint64_t)a * R.m) >> 32); > + uint32_t t = (((uint64_t)a * R->m) >> 32); > > - return (t + ((a - t) >> R.sh1)) >> R.sh2; > + return (t + ((a - t) >> R->sh1)) >> R->sh2; > } Do not add _u32 suffix for existing API. > > -struct rte_reciprocal > -rte_reciprocal_value(uint32_t d); > +static inline uint64_t > +mullhi_u64(uint64_t x, uint64_t y) > +{ > +#ifdef __SIZEOF_INT128__ > + __uint128_t xl = x; > + __uint128_t rl = xl * y; > + > + return (rl >> 64); > +#else > + uint64_t u0, u1, v0, v1, k, t; > + uint64_t w1, w2; > + uint64_t whi; > + > + u1 = x >> 32; u0 = x & 0xFFFFFFFF; > + v1 = y >> 32; v0 = y & 0xFFFFFFFF; > + > + t = u0*v0; > + k = t >> 32; > + > + t = u1*v0 + k; > + w1 = t & 0xFFFFFFFF; > + w2 = t >> 32; > + > + t = u0*v1 + w1; > + k = t >> 32; > + > + whi = u1*v1 + w2 + k; > + > + return whi; > +#endif > +} > + > +/** > + * Divide given unsigned 64-bit integer with pre calculated divisor. > + * > + * @param a > + * The 64-bit dividend. > + * @param R > + * The pointer to pre calculated divisor reciprocal structure. > + * > + * @return > + * The result of the division > + */ > +static inline uint64_t > +rte_reciprocal_divide_u64(uint64_t a, struct rte_reciprocal_u64 *R) > +{ > + uint64_t q = mullhi_u64(R->m, a); > + uint64_t t = ((a - q) >> 1) + q; > + > + return t >> R->sh1; > +} > + > +/** > + * Generate pre calculated divisor structure. > + * > + * @param d > + * The unsigned 32-bit divisor. > + * > + * @return > + * Divisor structure. > + */ > +struct rte_reciprocal_u32 > +rte_reciprocal_value_u32(uint32_t d); > + Do not add _u32 suffix for existing API. > +/** > + * Generate pre calculated divisor structure. > + * > + * @param d > + * The unsigned 64-bit divisor. > + * > + * @return > + * Divisor structure. > + */ > +struct rte_reciprocal_u64 > +rte_reciprocal_value_u64(uint64_t d); > > #endif /* _RTE_RECIPROCAL_H_ */ > diff --git a/lib/librte_eal/common/rte_reciprocal.c > b/lib/librte_eal/common/rte_reciprocal.c > index 7ab99b4..2024e62 100644 > --- a/lib/librte_eal/common/rte_reciprocal.c > +++ b/lib/librte_eal/common/rte_reciprocal.c > @@ -31,18 +31,13 @@ > * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH > DAMAGE. > */ > > -#include <stdio.h> > -#include <stdint.h> > - > -#include <rte_common.h> > - > -#include "rte_reciprocal.h" > +#include <rte_reciprocal.h> > > /* find largest set bit. > * portable and slow but does not matter for this usage. > */ > static inline int > -fls(uint32_t x) > +fls_u32(uint32_t x) > { > int b; > > @@ -54,14 +49,14 @@ fls(uint32_t x) > return 0; > } > Do not add _u32 suffix for existing API. > -struct rte_reciprocal > -rte_reciprocal_value(uint32_t d) > +struct rte_reciprocal_u32 > +rte_reciprocal_value_u32(uint32_t d) Do not add _u32 suffix for existing API. > { > - struct rte_reciprocal R; > + struct rte_reciprocal_u32 R; > uint64_t m; > int l; > > - l = fls(d - 1); > + l = fls_u32(d - 1); > m = ((1ULL << 32) * ((1ULL << l) - d)); > m /= d; > > @@ -72,3 +67,102 @@ rte_reciprocal_value(uint32_t d) > > return R; > } > + > +/* Code taken from Hacker's Delight: > + * http://www.hackersdelight.org/HDcode/divlu.c. > + * License permits inclusion here per: > + * http://www.hackersdelight.org/permissions.htm > + */ > +static inline uint64_t > +divide_128_div_64_to_64(uint64_t u1, uint64_t u0, uint64_t v, uint64_t *r) > +{ > + const uint64_t b = (1ULL << 32); /* Number base (16 bits). */ > + uint64_t un1, un0, /* Norm. dividend LSD's. */ > + vn1, vn0, /* Norm. divisor digits. */ > + q1, q0, /* Quotient digits. */ > + un64, un21, un10, /* Dividend digit pairs. */ > + rhat; /* A remainder. */ > + int s; /* Shift amount for norm. */ > + > + /* If overflow, set rem. to an impossible value. */ > + if (u1 >= v) { > + if (r != NULL) > + *r = (uint64_t) -1; > + return (uint64_t) -1; > + } > + > + /* Count leading zeros. */ > + s = __builtin_clzll(v); > + if (s > 0) { > + v = v << s; > + un64 = (u1 << s) | ((u0 >> (64 - s)) & (-s >> 31)); > + un10 = u0 << s; > + } else { > + > + un64 = u1 | u0; > + un10 = u0; > + } > + > + vn1 = v >> 32; > + vn0 = v & 0xFFFFFFFF; > + > + un1 = un10 >> 32; > + un0 = un10 & 0xFFFFFFFF; > + > + q1 = un64/vn1; > + rhat = un64 - q1*vn1; > +again1: > + if (q1 >= b || q1*vn0 > b*rhat + un1) { > + q1 = q1 - 1; > + rhat = rhat + vn1; > + if (rhat < b) > + goto again1; > + } > + > + un21 = un64*b + un1 - q1*v; > + > + q0 = un21/vn1; > + rhat = un21 - q0*vn1; > +again2: > + if (q0 >= b || q0*vn0 > b*rhat + un0) { > + q0 = q0 - 1; > + rhat = rhat + vn1; > + if (rhat < b) > + goto again2; > + } > + > + if (r != NULL) > + *r = (un21*b + un0 - q0*v) >> s; > + return q1*b + q0; > +} > + > +struct rte_reciprocal_u64 > +rte_reciprocal_value_u64(uint64_t d) > +{ > + struct rte_reciprocal_u64 R; > + > + const uint32_t fld = 63 - __builtin_clzll(d); > + > + if ((d & (d - 1)) == 0) { > + R.m = 0; > + R.sh1 = (fld - 1) | 0x40; > + } else { > + uint64_t rem; > + uint64_t multiplier; > + uint8_t more; > + > + multiplier = divide_128_div_64_to_64(1ULL << fld, 0, d, > &rem); > + multiplier += multiplier; > + > + const uint64_t twice_rem = rem + rem; > + if (twice_rem >= d || twice_rem < rem) > + multiplier += 1; > + more = fld; > + R.m = 1 + multiplier; > + R.sh1 = more | 0x40; > + } > + > + R.sh1 &= 0x3F; > + > + return R; > +} > diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map > b/lib/librte_eal/linuxapp/eal/rte_eal_version.map > index 2070cba..2671627 100644 > --- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map > +++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map > @@ -246,6 +246,7 @@ EXPERIMENTAL { > DPDK_17.11 { > global: > > - rte_reciprocal_value; > + rte_reciprocal_value_u32; Do not add _u32 suffix for existing API. > + rte_reciprocal_value_u64; > > } DPDK_17.08; > diff --git a/lib/librte_sched/Makefile b/lib/librte_sched/Makefile > index 569656b..a2fd6f3 100644 > --- a/lib/librte_sched/Makefile > +++ b/lib/librte_sched/Makefile > @@ -54,6 +54,8 @@ LIBABIVER := 1 > SRCS-$(CONFIG_RTE_LIBRTE_SCHED) += rte_sched.c rte_red.c rte_approx.c > > # install includes > -SYMLINK-$(CONFIG_RTE_LIBRTE_SCHED)-include := rte_sched.h > rte_bitmap.h rte_sched_common.h rte_red.h rte_approx.h > +SYMLINK-$(CONFIG_RTE_LIBRTE_SCHED)-include := rte_sched.h > rte_bitmap.h > +SYMLINK-$(CONFIG_RTE_LIBRTE_SCHED)-include += rte_sched_common.h > rte_red.h > +SYMLINK-$(CONFIG_RTE_LIBRTE_SCHED)-include += rte_approx.h > > include $(RTE_SDK)/mk/rte.lib.mk > diff --git a/lib/librte_sched/rte_sched.c b/lib/librte_sched/rte_sched.c > index 3b8ccaa..7bb6d51 100644 > --- a/lib/librte_sched/rte_sched.c > +++ b/lib/librte_sched/rte_sched.c > @@ -228,7 +228,7 @@ struct rte_sched_port { > uint64_t time_cpu_cycles; /* Current CPU time measured in CPU > cyles */ > uint64_t time_cpu_bytes; /* Current CPU time measured in bytes > */ > uint64_t time; /* Current NIC TX time measured in bytes > */ > - struct rte_reciprocal inv_cycles_per_byte; /* CPU cycles per byte */ > + struct rte_reciprocal_u32 inv_cycles_per_byte; /* CPU cycles per > byte */ > > /* Scheduling loop detection */ > uint32_t pipe_loop; > @@ -677,7 +677,7 @@ rte_sched_port_config(struct > rte_sched_port_params *params) > > cycles_per_byte = (rte_get_tsc_hz() << RTE_SCHED_TIME_SHIFT) > / params->rate; > - port->inv_cycles_per_byte = rte_reciprocal_value(cycles_per_byte); > + port->inv_cycles_per_byte = > rte_reciprocal_value_u32(cycles_per_byte); > Do not add _u32 suffix for existing API. > /* Scheduling loop detection */ > port->pipe_loop = RTE_SCHED_PIPE_INVALID; > @@ -2147,8 +2147,9 @@ rte_sched_port_time_resync(struct > rte_sched_port *port) > uint64_t bytes_diff; > > /* Compute elapsed time in bytes */ > - bytes_diff = rte_reciprocal_divide(cycles_diff << > RTE_SCHED_TIME_SHIFT, > - port->inv_cycles_per_byte); > + bytes_diff = rte_reciprocal_divide_u32( Do not add _u32 suffix for existing API. > + cycles_diff << RTE_SCHED_TIME_SHIFT, > + &port->inv_cycles_per_byte); > > /* Advance port time */ > port->time_cpu_cycles = cycles; > -- > 2.7.4
