Section: Linux Programmer's Manual (2)
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bdflush - start, flush, or tune buffer-dirty-flush daemon
int bdflush(int func, long *address);
int bdflush(int func, long data);
Since Linux 2.6,
this system call is deprecated and does nothing.
It is likely to disappear altogether in a future kernel release.
Nowadays, the task performed by
is handled by the kernel
starts, flushes, or tunes the buffer-dirty-flush daemon.
Only a privileged process (one with the
capability) may call
is negative or 0, and no daemon has been started, then
enters the daemon code and never returns.
some dirty buffers are written to disk.
is 2 or more and is even (low bit is 0), then
is the address of a long word,
and the tuning parameter numbered
is returned to the caller in that address.
is 3 or more and is odd (low bit is 1), then
is a long word,
and the kernel sets tuning parameter numbered
to that value.
The set of parameters, their values, and their valid ranges
are defined in the Linux kernel source file
is negative or 0 and the daemon successfully starts,
Otherwise, the return value is 0 on success and -1 on failure, with
set to indicate the error.
An attempt was made to enter the daemon code after
another process has already entered.
points outside your accessible address space.
An attempt was made to read or write an invalid parameter number,
or to write an invalid value to a parameter.
Caller does not have the
is Linux-specific and should not be used in programs
intended to be portable.
This page is part of release 3.74 of the Linux
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
- RETURN VALUE
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