Message ID | 20220518191424.3630729-4-adhemerval.zanella@linaro.org |
---|---|
State | New |
Headers | show |
Series | Add arc4random support | expand |
* Adhemerval Zanella via Libc-alpha: > diff --git a/benchtests/bench-arc4random.c b/benchtests/bench-arc4random.c > new file mode 100644 > index 0000000000..626f2ba48c > --- /dev/null > +++ b/benchtests/bench-arc4random.c > @@ -0,0 +1,224 @@ > +/* Prevent compiler to optimize away call. */ > +#define DO_NOT_OPTIMIZE(__value) \ > + ({ \ > + __typeof (__value) __v = (__value); \ > + asm volatile("" : : "r,m" (__v) : "memory");\ > + }) Missing space after “volatile”. Maybe this should be a generic building block for benchtests? > +static void > +run_bench (json_ctx_t *json_ctx, const char *name, > + char *const*fnames, size_t fnameslen, > + void (*bench)(json_ctx_t *ctx)) Missing space between “)(”. > diff --git a/stdlib/arc4random.c b/stdlib/arc4random.c > index f6553dfd7d..74c917b9b9 100644 > --- a/stdlib/arc4random.c > +++ b/stdlib/arc4random.c > @@ -25,9 +25,9 @@ > #include <sys/param.h> > #include <sys/random.h> > > -/* Besides the cipher state 'ctx', it keeps two counters: 'have' is the > - current valid bytes not yet consumed in 'buf', while 'count' is the maximum > - number of bytes until a reseed. > +/* arc4random keeps two counters: 'have' is the current valid bytes not yet > + consumed in 'buf' while 'count' is the maximum number of bytes until a > + reseed. > > Both the initial seed and reseed try to obtain entropy from the kernel > and abort the process if none could be obtained. > @@ -81,10 +81,10 @@ arc4random_getrandom_failure (void) > __libc_fatal ("Fatal glibc error: Cannot get entropy for arc4random\n"); > } > > -/* Fork detection is done by checking if MADV_WIPEONFORK supported. If not > - the fork callback will reset the state on the fork call. It does not > - handle direct clone calls, nor vfork or _Fork (arc4random is not > - async-signal-safe due the internal lock usage). */ > +/* If the kernel supports MADV_WIPEONFORK it is used to provide fork > + detection. Otherwise, the state is resetied with an atfork handler. The > + latter does not handle direct clone calls, nor vfork or _Fork (arc4random > + is not async-signal-safe due to the internal lock usage). */ > static void > arc4random_init (uint8_t *buf) > { I think this belongs into some other patch. Thanks, Florian
> On 28 Jun 2022, at 09:01, Florian Weimer <fweimer@redhat.com> wrote: > > * Adhemerval Zanella via Libc-alpha: > >> diff --git a/benchtests/bench-arc4random.c b/benchtests/bench-arc4random.c >> new file mode 100644 >> index 0000000000..626f2ba48c >> --- /dev/null >> +++ b/benchtests/bench-arc4random.c >> @@ -0,0 +1,224 @@ > >> +/* Prevent compiler to optimize away call. */ >> +#define DO_NOT_OPTIMIZE(__value) \ >> + ({ \ >> + __typeof (__value) __v = (__value); \ >> + asm volatile("" : : "r,m" (__v) : "memory");\ >> + }) > > Missing space after “volatile”. Ack. > > Maybe this should be a generic building block for benchtests? Indeed, I moved it to benchtests/bench-util.h. > >> +static void >> +run_bench (json_ctx_t *json_ctx, const char *name, >> + char *const*fnames, size_t fnameslen, >> + void (*bench)(json_ctx_t *ctx)) > > Missing space between “)(”. Ack. > > >> diff --git a/stdlib/arc4random.c b/stdlib/arc4random.c >> index f6553dfd7d..74c917b9b9 100644 >> --- a/stdlib/arc4random.c >> +++ b/stdlib/arc4random.c >> @@ -25,9 +25,9 @@ >> #include <sys/param.h> >> #include <sys/random.h> >> >> -/* Besides the cipher state 'ctx', it keeps two counters: 'have' is the >> - current valid bytes not yet consumed in 'buf', while 'count' is the maximum >> - number of bytes until a reseed. >> +/* arc4random keeps two counters: 'have' is the current valid bytes not yet >> + consumed in 'buf' while 'count' is the maximum number of bytes until a >> + reseed. >> >> Both the initial seed and reseed try to obtain entropy from the kernel >> and abort the process if none could be obtained. >> @@ -81,10 +81,10 @@ arc4random_getrandom_failure (void) >> __libc_fatal ("Fatal glibc error: Cannot get entropy for arc4random\n"); >> } >> >> -/* Fork detection is done by checking if MADV_WIPEONFORK supported. If not >> - the fork callback will reset the state on the fork call. It does not >> - handle direct clone calls, nor vfork or _Fork (arc4random is not >> - async-signal-safe due the internal lock usage). */ >> +/* If the kernel supports MADV_WIPEONFORK it is used to provide fork >> + detection. Otherwise, the state is resetied with an atfork handler. The >> + latter does not handle direct clone calls, nor vfork or _Fork (arc4random >> + is not async-signal-safe due to the internal lock usage). */ >> static void >> arc4random_init (uint8_t *buf) >> { > > I think this belongs into some other patch. Indeed, I will fix it. > > Thanks, > Florian >
On Wed, May 18, 2022 at 12:15 PM Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> wrote: > > It shows both throughput (total bytes obtained in the test duration) > and latecy for both arc4random and arc4random_buf with different > sizes. > > Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu. > --- > benchtests/Makefile | 5 +- > benchtests/bench-arc4random.c | 224 ++++++++++++++++++++++++++++++++++ > stdlib/arc4random.c | 14 +-- > 3 files changed, 235 insertions(+), 8 deletions(-) > create mode 100644 benchtests/bench-arc4random.c > > diff --git a/benchtests/Makefile b/benchtests/Makefile > index de9de5cf58..76583d45a3 100644 > --- a/benchtests/Makefile > +++ b/benchtests/Makefile > @@ -227,7 +227,10 @@ LOCALES := \ > include ../gen-locales.mk > endif > > -stdlib-benchset := strtod > +stdlib-benchset := \ > + arc4random \ > + strtod \ > + # stdlib-benchset > > stdio-common-benchset := sprintf > > diff --git a/benchtests/bench-arc4random.c b/benchtests/bench-arc4random.c > new file mode 100644 > index 0000000000..626f2ba48c > --- /dev/null > +++ b/benchtests/bench-arc4random.c > @@ -0,0 +1,224 @@ > +/* arc4random benchmarks. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#include "bench-timing.h" > +#include "json-lib.h" > +#include <array_length.h> > +#include <intprops.h> > +#include <signal.h> > +#include <stdbool.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <support/support.h> > +#include <support/timespec.h> > +#include <support/xthread.h> > + > +/* Prevent compiler to optimize away call. */ > +#define DO_NOT_OPTIMIZE(__value) \ > + ({ \ > + __typeof (__value) __v = (__value); \ > + asm volatile("" : : "r,m" (__v) : "memory");\ > + }) This might be useful to have in the support header. bench-hash-func.c has essentially the same code. > + > +static volatile sig_atomic_t timer_finished; > + > +static void timer_callback (int unused) > +{ > + timer_finished = 1; > +} > + > +static timer_t timer; > + > +/* Run for approximately DURATION seconds, and it does not matter who > + receive the signal (so not need to mask it on main thread). */ > +static void > +timer_start (void) > +{ > + timer_finished = 0; > + timer = support_create_timer (DURATION, 0, false, timer_callback); > +} > +static void > +timer_stop (void) > +{ > + support_delete_timer (timer); > +} > + > +static const uint32_t sizes[] = { 0, 16, 32, 48, 64, 80, 96, 112, 128 }; > + > +static double > +bench_throughput (void) > +{ > + uint64_t n = 0; > + > + struct timespec start, end; > + clock_gettime (CLOCK_MONOTONIC, &start); > + while (1) > + { > + DO_NOT_OPTIMIZE (arc4random ()); > + n++; > + > + if (timer_finished == 1) > + break; > + } > + clock_gettime (CLOCK_MONOTONIC, &end); > + struct timespec diff = timespec_sub (end, start); > + > + double total = (double) n * sizeof (uint32_t); > + double duration = (double) diff.tv_sec > + + (double) diff.tv_nsec / TIMESPEC_HZ; > + > + return total / duration; > +} > + > +static double > +bench_latency (void) > +{ > + timing_t start, stop, cur; > + const size_t iters = 1024; > + > + TIMING_NOW (start); > + for (size_t i = 0; i < iters; i++) > + DO_NOT_OPTIMIZE (arc4random ()); > + TIMING_NOW (stop); > + > + TIMING_DIFF (cur, start, stop); > + > + return (double) (cur) / (double) iters; > +} > + > +static double > +bench_buf_throughput (size_t len) > +{ > + uint8_t buf[len]; > + uint64_t n = 0; > + > + struct timespec start, end; > + clock_gettime (CLOCK_MONOTONIC, &start); > + while (1) > + { > + arc4random_buf (buf, len); > + n++; > + > + if (timer_finished == 1) > + break; > + } > + clock_gettime (CLOCK_MONOTONIC, &end); > + struct timespec diff = timespec_sub (end, start); > + > + double total = (double) n * len; > + double duration = (double) diff.tv_sec > + + (double) diff.tv_nsec / TIMESPEC_HZ; > + > + return total / duration; > +} > + > +static double > +bench_buf_latency (size_t len) > +{ > + timing_t start, stop, cur; > + const size_t iters = 1024; > + > + uint8_t buf[len]; > + > + TIMING_NOW (start); > + for (size_t i = 0; i < iters; i++) > + arc4random_buf (buf, len); > + TIMING_NOW (stop); > + > + TIMING_DIFF (cur, start, stop); > + > + return (double) (cur) / (double) iters; > +} > + > +static void > +bench_singlethread (json_ctx_t *json_ctx) > +{ > + json_element_object_begin (json_ctx); > + > + json_array_begin (json_ctx, "throughput"); > + for (int i = 0; i < array_length (sizes); i++) > + { > + timer_start (); > + double r = sizes[i] == 0 > + ? bench_throughput () : bench_buf_throughput (sizes[i]); > + timer_stop (); > + > + json_element_double (json_ctx, r); > + } > + json_array_end (json_ctx); > + > + json_array_begin (json_ctx, "latency"); > + for (int i = 0; i < array_length (sizes); i++) > + { > + timer_start (); > + double r = sizes[i] == 0 > + ? bench_latency () : bench_buf_latency (sizes[i]); > + timer_stop (); > + > + json_element_double (json_ctx, r); > + } > + json_array_end (json_ctx); > + > + json_element_object_end (json_ctx); > +} > + > +static void > +run_bench (json_ctx_t *json_ctx, const char *name, > + char *const*fnames, size_t fnameslen, > + void (*bench)(json_ctx_t *ctx)) > +{ > + json_attr_object_begin (json_ctx, name); > + json_array_begin (json_ctx, "functions"); > + for (int i = 0; i < fnameslen; i++) > + json_element_string (json_ctx, fnames[i]); > + json_array_end (json_ctx); > + > + json_array_begin (json_ctx, "results"); > + bench (json_ctx); > + json_array_end (json_ctx); > + json_attr_object_end (json_ctx); > +} > + > +static int > +do_test (void) > +{ > + char *fnames[array_length (sizes)]; > + for (int i = 0; i < array_length (sizes); i++) > + if (sizes[i] == 0) > + fnames[i] = xasprintf ("arc4random"); > + else > + fnames[i] = xasprintf ("arc4random_buf(%u)", sizes[i]); > + > + json_ctx_t json_ctx; > + json_init (&json_ctx, 0, stdout); > + > + json_document_begin (&json_ctx); > + json_attr_string (&json_ctx, "timing_type", TIMING_TYPE); > + > + run_bench (&json_ctx, "single-thread", fnames, array_length (fnames), > + bench_singlethread); > + > + json_document_end (&json_ctx); > + > + for (int i = 0; i < array_length (sizes); i++) > + free (fnames[i]); > + > + return 0; > +} > + > +#include <support/test-driver.c> > diff --git a/stdlib/arc4random.c b/stdlib/arc4random.c > index f6553dfd7d..74c917b9b9 100644 > --- a/stdlib/arc4random.c > +++ b/stdlib/arc4random.c > @@ -25,9 +25,9 @@ > #include <sys/param.h> > #include <sys/random.h> > > -/* Besides the cipher state 'ctx', it keeps two counters: 'have' is the > - current valid bytes not yet consumed in 'buf', while 'count' is the maximum > - number of bytes until a reseed. > +/* arc4random keeps two counters: 'have' is the current valid bytes not yet > + consumed in 'buf' while 'count' is the maximum number of bytes until a > + reseed. > > Both the initial seed and reseed try to obtain entropy from the kernel > and abort the process if none could be obtained. > @@ -81,10 +81,10 @@ arc4random_getrandom_failure (void) > __libc_fatal ("Fatal glibc error: Cannot get entropy for arc4random\n"); > } > > -/* Fork detection is done by checking if MADV_WIPEONFORK supported. If not > - the fork callback will reset the state on the fork call. It does not > - handle direct clone calls, nor vfork or _Fork (arc4random is not > - async-signal-safe due the internal lock usage). */ > +/* If the kernel supports MADV_WIPEONFORK it is used to provide fork > + detection. Otherwise, the state is resetied with an atfork handler. The > + latter does not handle direct clone calls, nor vfork or _Fork (arc4random > + is not async-signal-safe due to the internal lock usage). */ > static void > arc4random_init (uint8_t *buf) > { > -- > 2.34.1 >
On Tue, Jun 28, 2022 at 10:13 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote: > > On Wed, May 18, 2022 at 12:15 PM Adhemerval Zanella via Libc-alpha > <libc-alpha@sourceware.org> wrote: > > > > It shows both throughput (total bytes obtained in the test duration) > > and latecy for both arc4random and arc4random_buf with different > > sizes. > > > > Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu. > > --- > > benchtests/Makefile | 5 +- > > benchtests/bench-arc4random.c | 224 ++++++++++++++++++++++++++++++++++ > > stdlib/arc4random.c | 14 +-- > > 3 files changed, 235 insertions(+), 8 deletions(-) > > create mode 100644 benchtests/bench-arc4random.c > > > > diff --git a/benchtests/Makefile b/benchtests/Makefile > > index de9de5cf58..76583d45a3 100644 > > --- a/benchtests/Makefile > > +++ b/benchtests/Makefile > > @@ -227,7 +227,10 @@ LOCALES := \ > > include ../gen-locales.mk > > endif > > > > -stdlib-benchset := strtod > > +stdlib-benchset := \ > > + arc4random \ > > + strtod \ > > + # stdlib-benchset > > > > stdio-common-benchset := sprintf > > > > diff --git a/benchtests/bench-arc4random.c b/benchtests/bench-arc4random.c > > new file mode 100644 > > index 0000000000..626f2ba48c > > --- /dev/null > > +++ b/benchtests/bench-arc4random.c > > @@ -0,0 +1,224 @@ > > +/* arc4random benchmarks. > > + Copyright (C) 2022 Free Software Foundation, Inc. > > + This file is part of the GNU C Library. > > + > > + The GNU C Library is free software; you can redistribute it and/or > > + modify it under the terms of the GNU Lesser General Public > > + License as published by the Free Software Foundation; either > > + version 2.1 of the License, or (at your option) any later version. > > + > > + The GNU C Library is distributed in the hope that it will be useful, > > + but WITHOUT ANY WARRANTY; without even the implied warranty of > > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > > + Lesser General Public License for more details. > > + > > + You should have received a copy of the GNU Lesser General Public > > + License along with the GNU C Library; if not, see > > + <https://www.gnu.org/licenses/>. */ > > + > > +#include "bench-timing.h" > > +#include "json-lib.h" > > +#include <array_length.h> > > +#include <intprops.h> > > +#include <signal.h> > > +#include <stdbool.h> > > +#include <stdio.h> > > +#include <stdlib.h> > > +#include <support/support.h> > > +#include <support/timespec.h> > > +#include <support/xthread.h> > > + > > +/* Prevent compiler to optimize away call. */ > > +#define DO_NOT_OPTIMIZE(__value) \ > > + ({ \ > > + __typeof (__value) __v = (__value); \ > > + asm volatile("" : : "r,m" (__v) : "memory");\ > > + }) > > This might be useful to have in the support header. > bench-hash-func.c has essentially the same code. Ah florian beat me to it. Can you update bench-hash-func.c when you put this in a header? Defined in bench-hash-func.c and used in bench-hash-func-kernel.h > > > + > > +static volatile sig_atomic_t timer_finished; > > + > > +static void timer_callback (int unused) > > +{ > > + timer_finished = 1; > > +} > > + > > +static timer_t timer; > > + > > +/* Run for approximately DURATION seconds, and it does not matter who > > + receive the signal (so not need to mask it on main thread). */ > > +static void > > +timer_start (void) > > +{ > > + timer_finished = 0; > > + timer = support_create_timer (DURATION, 0, false, timer_callback); > > +} > > +static void > > +timer_stop (void) > > +{ > > + support_delete_timer (timer); > > +} > > + > > +static const uint32_t sizes[] = { 0, 16, 32, 48, 64, 80, 96, 112, 128 }; > > + > > +static double > > +bench_throughput (void) > > +{ > > + uint64_t n = 0; > > + > > + struct timespec start, end; > > + clock_gettime (CLOCK_MONOTONIC, &start); > > + while (1) > > + { > > + DO_NOT_OPTIMIZE (arc4random ()); > > + n++; > > + > > + if (timer_finished == 1) > > + break; > > + } > > + clock_gettime (CLOCK_MONOTONIC, &end); > > + struct timespec diff = timespec_sub (end, start); > > + > > + double total = (double) n * sizeof (uint32_t); > > + double duration = (double) diff.tv_sec > > + + (double) diff.tv_nsec / TIMESPEC_HZ; > > + > > + return total / duration; > > +} > > + > > +static double > > +bench_latency (void) > > +{ > > + timing_t start, stop, cur; > > + const size_t iters = 1024; > > + > > + TIMING_NOW (start); > > + for (size_t i = 0; i < iters; i++) > > + DO_NOT_OPTIMIZE (arc4random ()); > > + TIMING_NOW (stop); > > + > > + TIMING_DIFF (cur, start, stop); > > + > > + return (double) (cur) / (double) iters; > > +} > > + > > +static double > > +bench_buf_throughput (size_t len) > > +{ > > + uint8_t buf[len]; > > + uint64_t n = 0; > > + > > + struct timespec start, end; > > + clock_gettime (CLOCK_MONOTONIC, &start); > > + while (1) > > + { > > + arc4random_buf (buf, len); > > + n++; > > + > > + if (timer_finished == 1) > > + break; > > + } > > + clock_gettime (CLOCK_MONOTONIC, &end); > > + struct timespec diff = timespec_sub (end, start); > > + > > + double total = (double) n * len; > > + double duration = (double) diff.tv_sec > > + + (double) diff.tv_nsec / TIMESPEC_HZ; > > + > > + return total / duration; > > +} > > + > > +static double > > +bench_buf_latency (size_t len) > > +{ > > + timing_t start, stop, cur; > > + const size_t iters = 1024; > > + > > + uint8_t buf[len]; > > + > > + TIMING_NOW (start); > > + for (size_t i = 0; i < iters; i++) > > + arc4random_buf (buf, len); > > + TIMING_NOW (stop); > > + > > + TIMING_DIFF (cur, start, stop); > > + > > + return (double) (cur) / (double) iters; > > +} > > + > > +static void > > +bench_singlethread (json_ctx_t *json_ctx) > > +{ > > + json_element_object_begin (json_ctx); > > + > > + json_array_begin (json_ctx, "throughput"); > > + for (int i = 0; i < array_length (sizes); i++) > > + { > > + timer_start (); > > + double r = sizes[i] == 0 > > + ? bench_throughput () : bench_buf_throughput (sizes[i]); > > + timer_stop (); > > + > > + json_element_double (json_ctx, r); > > + } > > + json_array_end (json_ctx); > > + > > + json_array_begin (json_ctx, "latency"); > > + for (int i = 0; i < array_length (sizes); i++) > > + { > > + timer_start (); > > + double r = sizes[i] == 0 > > + ? bench_latency () : bench_buf_latency (sizes[i]); > > + timer_stop (); > > + > > + json_element_double (json_ctx, r); > > + } > > + json_array_end (json_ctx); > > + > > + json_element_object_end (json_ctx); > > +} > > + > > +static void > > +run_bench (json_ctx_t *json_ctx, const char *name, > > + char *const*fnames, size_t fnameslen, > > + void (*bench)(json_ctx_t *ctx)) > > +{ > > + json_attr_object_begin (json_ctx, name); > > + json_array_begin (json_ctx, "functions"); > > + for (int i = 0; i < fnameslen; i++) > > + json_element_string (json_ctx, fnames[i]); > > + json_array_end (json_ctx); > > + > > + json_array_begin (json_ctx, "results"); > > + bench (json_ctx); > > + json_array_end (json_ctx); > > + json_attr_object_end (json_ctx); > > +} > > + > > +static int > > +do_test (void) > > +{ > > + char *fnames[array_length (sizes)]; > > + for (int i = 0; i < array_length (sizes); i++) > > + if (sizes[i] == 0) > > + fnames[i] = xasprintf ("arc4random"); > > + else > > + fnames[i] = xasprintf ("arc4random_buf(%u)", sizes[i]); > > + > > + json_ctx_t json_ctx; > > + json_init (&json_ctx, 0, stdout); > > + > > + json_document_begin (&json_ctx); > > + json_attr_string (&json_ctx, "timing_type", TIMING_TYPE); > > + > > + run_bench (&json_ctx, "single-thread", fnames, array_length (fnames), > > + bench_singlethread); > > + > > + json_document_end (&json_ctx); > > + > > + for (int i = 0; i < array_length (sizes); i++) > > + free (fnames[i]); > > + > > + return 0; > > +} > > + > > +#include <support/test-driver.c> > > diff --git a/stdlib/arc4random.c b/stdlib/arc4random.c > > index f6553dfd7d..74c917b9b9 100644 > > --- a/stdlib/arc4random.c > > +++ b/stdlib/arc4random.c > > @@ -25,9 +25,9 @@ > > #include <sys/param.h> > > #include <sys/random.h> > > > > -/* Besides the cipher state 'ctx', it keeps two counters: 'have' is the > > - current valid bytes not yet consumed in 'buf', while 'count' is the maximum > > - number of bytes until a reseed. > > +/* arc4random keeps two counters: 'have' is the current valid bytes not yet > > + consumed in 'buf' while 'count' is the maximum number of bytes until a > > + reseed. > > > > Both the initial seed and reseed try to obtain entropy from the kernel > > and abort the process if none could be obtained. > > @@ -81,10 +81,10 @@ arc4random_getrandom_failure (void) > > __libc_fatal ("Fatal glibc error: Cannot get entropy for arc4random\n"); > > } > > > > -/* Fork detection is done by checking if MADV_WIPEONFORK supported. If not > > - the fork callback will reset the state on the fork call. It does not > > - handle direct clone calls, nor vfork or _Fork (arc4random is not > > - async-signal-safe due the internal lock usage). */ > > +/* If the kernel supports MADV_WIPEONFORK it is used to provide fork > > + detection. Otherwise, the state is resetied with an atfork handler. The > > + latter does not handle direct clone calls, nor vfork or _Fork (arc4random > > + is not async-signal-safe due to the internal lock usage). */ > > static void > > arc4random_init (uint8_t *buf) > > { > > -- > > 2.34.1 > >
> On 28 Jun 2022, at 14:14, Noah Goldstein <goldstein.w.n@gmail.com> wrote: > > On Tue, Jun 28, 2022 at 10:13 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote: > Ah florian beat me to it. > > Can you update bench-hash-func.c when you put > this in a header? > > Defined in bench-hash-func.c and used in bench-hash-func-kernel.h Alright.
diff --git a/benchtests/Makefile b/benchtests/Makefile index de9de5cf58..76583d45a3 100644 --- a/benchtests/Makefile +++ b/benchtests/Makefile @@ -227,7 +227,10 @@ LOCALES := \ include ../gen-locales.mk endif -stdlib-benchset := strtod +stdlib-benchset := \ + arc4random \ + strtod \ + # stdlib-benchset stdio-common-benchset := sprintf diff --git a/benchtests/bench-arc4random.c b/benchtests/bench-arc4random.c new file mode 100644 index 0000000000..626f2ba48c --- /dev/null +++ b/benchtests/bench-arc4random.c @@ -0,0 +1,224 @@ +/* arc4random benchmarks. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include "bench-timing.h" +#include "json-lib.h" +#include <array_length.h> +#include <intprops.h> +#include <signal.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <support/support.h> +#include <support/timespec.h> +#include <support/xthread.h> + +/* Prevent compiler to optimize away call. */ +#define DO_NOT_OPTIMIZE(__value) \ + ({ \ + __typeof (__value) __v = (__value); \ + asm volatile("" : : "r,m" (__v) : "memory");\ + }) + +static volatile sig_atomic_t timer_finished; + +static void timer_callback (int unused) +{ + timer_finished = 1; +} + +static timer_t timer; + +/* Run for approximately DURATION seconds, and it does not matter who + receive the signal (so not need to mask it on main thread). */ +static void +timer_start (void) +{ + timer_finished = 0; + timer = support_create_timer (DURATION, 0, false, timer_callback); +} +static void +timer_stop (void) +{ + support_delete_timer (timer); +} + +static const uint32_t sizes[] = { 0, 16, 32, 48, 64, 80, 96, 112, 128 }; + +static double +bench_throughput (void) +{ + uint64_t n = 0; + + struct timespec start, end; + clock_gettime (CLOCK_MONOTONIC, &start); + while (1) + { + DO_NOT_OPTIMIZE (arc4random ()); + n++; + + if (timer_finished == 1) + break; + } + clock_gettime (CLOCK_MONOTONIC, &end); + struct timespec diff = timespec_sub (end, start); + + double total = (double) n * sizeof (uint32_t); + double duration = (double) diff.tv_sec + + (double) diff.tv_nsec / TIMESPEC_HZ; + + return total / duration; +} + +static double +bench_latency (void) +{ + timing_t start, stop, cur; + const size_t iters = 1024; + + TIMING_NOW (start); + for (size_t i = 0; i < iters; i++) + DO_NOT_OPTIMIZE (arc4random ()); + TIMING_NOW (stop); + + TIMING_DIFF (cur, start, stop); + + return (double) (cur) / (double) iters; +} + +static double +bench_buf_throughput (size_t len) +{ + uint8_t buf[len]; + uint64_t n = 0; + + struct timespec start, end; + clock_gettime (CLOCK_MONOTONIC, &start); + while (1) + { + arc4random_buf (buf, len); + n++; + + if (timer_finished == 1) + break; + } + clock_gettime (CLOCK_MONOTONIC, &end); + struct timespec diff = timespec_sub (end, start); + + double total = (double) n * len; + double duration = (double) diff.tv_sec + + (double) diff.tv_nsec / TIMESPEC_HZ; + + return total / duration; +} + +static double +bench_buf_latency (size_t len) +{ + timing_t start, stop, cur; + const size_t iters = 1024; + + uint8_t buf[len]; + + TIMING_NOW (start); + for (size_t i = 0; i < iters; i++) + arc4random_buf (buf, len); + TIMING_NOW (stop); + + TIMING_DIFF (cur, start, stop); + + return (double) (cur) / (double) iters; +} + +static void +bench_singlethread (json_ctx_t *json_ctx) +{ + json_element_object_begin (json_ctx); + + json_array_begin (json_ctx, "throughput"); + for (int i = 0; i < array_length (sizes); i++) + { + timer_start (); + double r = sizes[i] == 0 + ? bench_throughput () : bench_buf_throughput (sizes[i]); + timer_stop (); + + json_element_double (json_ctx, r); + } + json_array_end (json_ctx); + + json_array_begin (json_ctx, "latency"); + for (int i = 0; i < array_length (sizes); i++) + { + timer_start (); + double r = sizes[i] == 0 + ? bench_latency () : bench_buf_latency (sizes[i]); + timer_stop (); + + json_element_double (json_ctx, r); + } + json_array_end (json_ctx); + + json_element_object_end (json_ctx); +} + +static void +run_bench (json_ctx_t *json_ctx, const char *name, + char *const*fnames, size_t fnameslen, + void (*bench)(json_ctx_t *ctx)) +{ + json_attr_object_begin (json_ctx, name); + json_array_begin (json_ctx, "functions"); + for (int i = 0; i < fnameslen; i++) + json_element_string (json_ctx, fnames[i]); + json_array_end (json_ctx); + + json_array_begin (json_ctx, "results"); + bench (json_ctx); + json_array_end (json_ctx); + json_attr_object_end (json_ctx); +} + +static int +do_test (void) +{ + char *fnames[array_length (sizes)]; + for (int i = 0; i < array_length (sizes); i++) + if (sizes[i] == 0) + fnames[i] = xasprintf ("arc4random"); + else + fnames[i] = xasprintf ("arc4random_buf(%u)", sizes[i]); + + json_ctx_t json_ctx; + json_init (&json_ctx, 0, stdout); + + json_document_begin (&json_ctx); + json_attr_string (&json_ctx, "timing_type", TIMING_TYPE); + + run_bench (&json_ctx, "single-thread", fnames, array_length (fnames), + bench_singlethread); + + json_document_end (&json_ctx); + + for (int i = 0; i < array_length (sizes); i++) + free (fnames[i]); + + return 0; +} + +#include <support/test-driver.c> diff --git a/stdlib/arc4random.c b/stdlib/arc4random.c index f6553dfd7d..74c917b9b9 100644 --- a/stdlib/arc4random.c +++ b/stdlib/arc4random.c @@ -25,9 +25,9 @@ #include <sys/param.h> #include <sys/random.h> -/* Besides the cipher state 'ctx', it keeps two counters: 'have' is the - current valid bytes not yet consumed in 'buf', while 'count' is the maximum - number of bytes until a reseed. +/* arc4random keeps two counters: 'have' is the current valid bytes not yet + consumed in 'buf' while 'count' is the maximum number of bytes until a + reseed. Both the initial seed and reseed try to obtain entropy from the kernel and abort the process if none could be obtained. @@ -81,10 +81,10 @@ arc4random_getrandom_failure (void) __libc_fatal ("Fatal glibc error: Cannot get entropy for arc4random\n"); } -/* Fork detection is done by checking if MADV_WIPEONFORK supported. If not - the fork callback will reset the state on the fork call. It does not - handle direct clone calls, nor vfork or _Fork (arc4random is not - async-signal-safe due the internal lock usage). */ +/* If the kernel supports MADV_WIPEONFORK it is used to provide fork + detection. Otherwise, the state is resetied with an atfork handler. The + latter does not handle direct clone calls, nor vfork or _Fork (arc4random + is not async-signal-safe due to the internal lock usage). */ static void arc4random_init (uint8_t *buf) {