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Make mmap() scalable

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It's now possible to create thousands of thousands of sparse independent
memory mappings, without any slowdown. The memory manager is better with
tracking memory protection now, particularly on Windows in a precise way
that can be restored during fork(). You now have the highest quality mem
manager possible. It's even better than some OSes like XNU, where mmap()
is implemented as an O(n) operation which means sadly things aren't much
improved over there. With this change the llamafile HTTP server endpoint
at /tokenize with a prompt of 50 tokens is now able to handle 2.6m r/sec
This commit is contained in:
Justine Tunney 2024-07-05 23:13:20 -07:00
parent 3756870635
commit 8c645fa1ee
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59 changed files with 1238 additions and 1067 deletions
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test/libc/intrin/mmap_scalability_test.c Normal file
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2024 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/struct/timespec.h"
#include "libc/dce.h"
#include "libc/intrin/kprintf.h"
#include "libc/runtime/runtime.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/prot.h"
#define BENCH(ITERATIONS, WORK_PER_RUN, CODE) \
do { \
struct timespec start = timespec_real(); \
for (int __i = 0; __i < ITERATIONS; ++__i) { \
asm volatile("" ::: "memory"); \
CODE; \
} \
long long work = (WORK_PER_RUN) * (ITERATIONS); \
double nanos = \
(timespec_tonanos(timespec_sub(timespec_real(), start)) + work - 1) / \
(double)work; \
kprintf("%'20ld ns %2dx %s\n", (long)nanos, (ITERATIONS), #CODE); \
} while (0)
void *randaddr(void) {
static unsigned long lcg = 1;
lcg *= 6364136223846793005;
lcg += 1442695040888963407;
return (void *)(lcg >> 48 << 28);
}
void map_unmap_one_page(void) {
void *p;
if ((p = mmap(randaddr(), 1, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0)) == MAP_FAILED)
__builtin_trap();
if (munmap(p, 1))
__builtin_trap();
}
int main() {
kprintf("\n");
BENCH(1000, 1, map_unmap_one_page());
// macos doesn't scale
if (IsXnu())
return 0;
// create lots of sparse mappings to put
// weight on __maps.maps. red-black tree
int n = 10000;
kprintf("%20s creating %d sparse maps...\n", "", n);
for (int i = 0; i < n; ++i) {
if (mmap(randaddr(), 1, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS,
-1, 0) == MAP_FAILED)
__builtin_trap();
}
BENCH(1000, 1, map_unmap_one_page());
}