Andreas Beck wrote:
> > > I just tried the "documented" solution:
> > > write(1,buffer,width*height*2); fdatasync(1);
> > Agh! That is not what fdatasync(1) is for!
>
> What else would it be for ? It in deed does make sure that the file actually
> gets written to disk, what lets me synchronize with the disk speed.
>
> What would you suggest to use ? fsync seems worse.
Well, not really... From sys_fdatasync:
/* this needs further work, at the moment it is identical to
fsync() */
down(&inode->i_sem);
err = file->f_op->fsync(file, dentry);
up(&inode->i_sem);
> The problem with both functions is, that their required runtime is of the
> order of the total file size, not the change file size.
>
> This causes my framerate to drop from full 25fps down to 4 fps after about
> 600 frames. ARGL.
How about just mmap()ing enough of the file to hold a few frames and
then munmap() it when those frames are written to the buffer?
Or are buffers not flushed on munmap?
Otherwise the only solution I can think of is periodicly calling
fdatasync() from another thread or process.
//Marcus
--
-------------------------------+------------------------------------
Marcus Sundberg | http://www.stacken.kth.se/~mackan/
Royal Institute of Technology | Phone: +46 707 295404
Stockholm, Sweden | E-Mail: [EMAIL PROTECTED]
