Merge pull request #20511 from archbirdplus

runtime page size detection
rework GeneralPurposeAllocator to reduce active mapping count
Allocator VTable API update

1 files changed, 18 insertions, 4 deletions

diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 365fb9f05f..1183408694 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -305,6 +305,13 @@ pub const MAP = switch (native_arch) {
     else => @compileError("missing std.os.linux.MAP constants for this architecture"),
 };
 
+pub const MREMAP = packed struct(u32) {
+    MAYMOVE: bool = false,
+    FIXED: bool = false,
+    DONTUNMAP: bool = false,
+    _: u29 = 0,
+};
+
 pub const O = switch (native_arch) {
     .x86_64 => packed struct(u32) {
         ACCMODE: ACCMODE = .RDONLY,
@@ -892,10 +899,6 @@ pub fn umount2(special: [*:0]const u8, flags: u32) usize {
 
 pub fn mmap(address: ?[*]u8, length: usize, prot: usize, flags: MAP, fd: i32, offset: i64) usize {
     if (@hasField(SYS, "mmap2")) {
-        // Make sure the offset is also specified in multiples of page size
-        if ((offset & (MMAP2_UNIT - 1)) != 0)
-            return @bitCast(-@as(isize, @intFromEnum(E.INVAL)));
-
         return syscall6(
             .mmap2,
             @intFromPtr(address),
@@ -934,6 +937,17 @@ pub fn mprotect(address: [*]const u8, length: usize, protection: usize) usize {
     return syscall3(.mprotect, @intFromPtr(address), length, protection);
 }
 
+pub fn mremap(old_addr: ?[*]const u8, old_len: usize, new_len: usize, flags: MREMAP, new_addr: ?[*]const u8) usize {
+    return syscall5(
+        .mremap,
+        @intFromPtr(old_addr),
+        old_len,
+        new_len,
+        @as(u32, @bitCast(flags)),
+        @intFromPtr(new_addr),
+    );
+}
+
 pub const MSF = struct {
     pub const ASYNC = 1;
     pub const INVALIDATE = 2;