запускать, очищать или настраивать демон buffer-dirty-flush (start, flush, or tune buffer-dirty-flush daemon)
Имя (Name)
bdflush - start, flush, or tune buffer-dirty-flush daemon
Синопсис (Synopsis)
#include <sys/kdaemon.h>
int bdflush(int func, long *address);
int bdflush(int func, long data);
Note: There is no glibc wrapper for this system call; see
VERSIONS.
Описание (Description)
Note: 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 bdflush() is handled by
the kernel pdflush thread.
bdflush() starts, flushes, or tunes the buffer-dirty-flush
daemon. Only a privileged process (one with the CAP_SYS_ADMIN
capability) may call bdflush().
If func is negative or 0, and no daemon has been started, then
bdflush() enters the daemon code and never returns.
If func is 1, some dirty buffers are written to disk.
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 value.
The set of parameters, their values, and their valid ranges are
defined in the Linux kernel source file fs/buffer.c.
Возвращаемое значение (Return value)
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.
Ошибки (Error)
EBUSY An attempt was made to enter the daemon code after another
process has already entered.
EFAULT address points outside your accessible address space.
EINVAL An attempt was made to read or write an invalid parameter
number, or to write an invalid value to a parameter.
EPERM Caller does not have the CAP_SYS_ADMIN capability.
Версии (Versions)
Since version 2.23, glibc no longer supports this obsolete system
call.
Стандарты (Conforming to)
bdflush() is Linux-specific and should not be used in programs
intended to be portable.
Смотри также (See also)
sync(1), fsync(2), sync(2)
