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Fix small matters and improve sysconf()

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- Fix mkdeps.com out of memory error
- Remove static memory from __get_cpu_count()
- Add support for passing hyphen to cat in cocmd
- Change more ZipOS errors from ENOTSUP to EROFS
- Specify mem_unit in sysinfo() output on BSD OSes
This commit is contained in:
Justine Tunney 2023-08-17 00:25:01 -07:00
parent eebc24b9cd
commit 3a9cac4892
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GPG key ID: BE714B4575D6E328
55 changed files with 411 additions and 262 deletions
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51
libc/runtime/getargmax.c
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@ -17,17 +17,50 @@
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/dce.h"
#include "libc/macros.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/sysv/consts/limits.h"
#include "libc/sysv/consts/rlimit.h"
#define CTL_KERN 1
#define KERN_ARGMAX 8
/**
* Returns `ARG_MAX` for host platform.
* Returns expensive but more correct version of `ARG_MAX`.
*/
int __arg_max(void) {
if (IsWindows()) return 32767;
if (IsLinux()) return 128 * 1024;
if (IsNetbsd()) return 256 * 1024;
if (IsFreebsd()) return 512 * 1024;
if (IsOpenbsd()) return 512 * 1024;
if (IsXnu()) return 1024 * 1024;
return ARG_MAX;
int __get_arg_max(void) {
if (IsLinux()) {
// You might think that just returning a constant 128KiB (ARG_MAX)
// would make sense, as this guy did:
//
// https://lkml.org/lkml/2017/11/15/813...
//
// I suspect a 128kB sysconf(_SC_ARG_MAX) is the sanest bet, simply
// because of that "conservative is better than aggressive".
//
// Especially since _technically_ we're still limiting things to that
// 128kB due to the single-string limit.
//
// Linus
//
// In practice that caused us trouble with toybox tests for xargs
// edge cases. The tests assume that they can at least reach the
// kernel's "minimum maximum" of 128KiB, but if we report 128KiB for
// _SC_ARG_MAX and xargs starts subtracting the environment space
// and so on from that, then xargs will think it's run out of space
// when given 128KiB of data, which should always work. See this
// thread for more:
//
// http://lists.landley.net/pipermail/toybox-landley.net/2019-November/011229.html
//
// So let's resign ourselves to tracking what the kernel actually
// does. Right now (2019, Linux 5.3) that amounts to:
uint64_t stacksz;
stacksz = __get_rlimit(RLIMIT_STACK);
return MAX(MIN(stacksz / 4, 3 * (8 * 1024 * 1024) / 4), _ARG_MAX);
} else if (IsBsd()) {
return __get_sysctl(CTL_KERN, KERN_ARGMAX);
} else {
return _ARG_MAX;
}
}