bdflush - start, flush, or tune buffer-dirty-flush daemon
int bdflush(int func, long *address);
int bdflush(int func, long data);
bdflush starts, flushes, or tunes the
buffer-dirty-flush daemon. Only the super-user may call
If func is negative or 0, and no daemon has been
started, then bdflush enters the daemon code and
If func is 1, some dirty buffers are written to
If func is 2 or more and is even (low bit is 0), then
address is the address of a long word, and the tuning
parameter numbered (func-2)/2 is returned to the
caller in that address.
If func is 3 or more and is odd (low bit is 1), then
data is a long word, and the kernel sets tuning
parameter numbered (func-3)/2 to that
The set of parameters, their values, and their legal ranges
are defined in the kernel source file
If func is negative or 0 and the daemon successfully
starts, bdflush never returns. Otherwise, the return
value is 0 on success and -1 on failure, with errno
set to indicate the error.
- Caller is not super-user.
- address points outside your accessible address space.
- An attempt was made to enter the daemon code after another process has already entered.
- An attempt was made to read or write an invalid parameter number, or to write an invalid value to a parameter.
bdflush is Linux specific and should not be used in programs intended to be portable.
fsync(2), sync(2), update(8), sync(8)?