Section (2) getpagesize
getpagesize — get memory page size
returns the number of bytes in a memory page, where page is
a fixed-length block, the unit for memory allocation and file
mapping performed by mmap(2).
SVr4, 4.4BSD, SUSv2. In SUSv2 the
getpagesize() call is labeled LEGACY, and
in POSIX.1-2001 it has been dropped; HP-UX does not have this
Portable applications should employ
#include <unistd.h> long sz = sysconf(_SC_PAGESIZE);
(Most systems allow the synonym
present as a Linux system call depends on the architecture.
If it is, it returns the kernel symbol
PAGE_SIZE, whose value depends on the
architecture and machine model. Generally, one uses binaries
that are dependent on the architecture but not on the machine
model, in order to have a single binary distribution per
architecture. This means that a user program should not find
PAGE_SIZE at compile time from
a header file, but use an actual system call, at least for
those architectures (like sun4) where this dependency exists.
Here glibc 2.0 fails because its
getpagesize() returns a statically derived
value, and does not use a system call. Things are OK in glibc
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Copyright (C) 2001 Andries Brouwer <aebcwi.nl>
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