Align MP heap allocations to cache lines

Author: tannewt

ports/mimxrt10xx/mpconfigport.h

@@ -37,7 +37,6 @@ extern uint8_t _ld_filesystem_start;
 extern uint8_t _ld_filesystem_end;
 extern uint8_t _ld_default_stack_size;
 
-// 20kiB stack
 #define CIRCUITPY_DEFAULT_STACK_SIZE                ((uint32_t)&_ld_default_stack_size)
 #define MICROPY_PY_BUILTINS_NOTIMPLEMENTED          (0)
 #define MICROPY_PY_FUNCTION_ATTRS                   (0)
@@ -47,6 +46,10 @@ extern uint8_t _ld_default_stack_size;
 #define CIRCUITPY_INTERNAL_FLASH_FILESYSTEM_START_ADDR ((uint32_t)&_ld_filesystem_start)
 #define CIRCUITPY_INTERNAL_FLASH_FILESYSTEM_SIZE ((uint32_t)(&_ld_filesystem_end - &_ld_filesystem_start))
 
+// Allocate 32 bytes at a time instead of the default 16 so that allocated buffers
+// are aligned to cache lines.
+#define MICROPY_BYTES_PER_GC_BLOCK              (32)
+
 #include "py/circuitpy_mpconfig.h"
 
 #define MICROPY_PORT_ROOT_POINTERS \