Hi!

> I'd really suggest _just_ the "full image". Nothing else is probably ever 
> worth supporting. Your "snapshot to disk" wouldn't be _quite_ as simple as 
> "echo disk > /sys/power/state", but it should not necessarily be much 
> worse than
> 
>       snapshot_kernel | gzip -9 > /dev/snapshot

Yep, we "freeze too much", so we can't just use the shell and pipe
it. Too bad.

  218 int write_image(char *resume_dev_name)
  219 {
  220   static struct swap_map_handle handle;
  221   struct swsusp_info *header;
  222   unsigned long start;
  223   int fd;
  224   int error;
  225 
  226   fd = open(resume_dev_name, O_RDWR | O_SYNC);
  227   if (fd < 0) {
  228           printf("suspend: Could not open resume device\n");
  229           return error;
  230   }
  231   error = read(dev, buffer, PAGE_SIZE);
  232   if (error < PAGE_SIZE)
  233           return error < 0 ? error : -EFAULT;
  234   header = (struct swsusp_info *)buffer;
  235   if (!enough_swap(header->pages)) {
  236           printf("suspend: Not enough free swap\n");
  237           return -ENOSPC;
  238   }
  239   error = init_swap_writer(&handle, fd);
  240   if (!error) {
  241           start = handle.cur_swap;
  242           error = swap_write_page(&handle, header);
  243   }
  244   if (!error)
  245           error = save_image(&handle, header->pages - 1);
  246   if (!error) {
  247           flush_swap_writer(&handle);
  248           printf( "S" );
  249           error = mark_swap(fd, start);
  250           printf( "|\n" );
  251   }
  252   fsync(fd);
  253   close(fd);
  254   return error;
  255 }

This is basically the loop above, made complex by the fact that we do
not want to have separate partition for snapshot; we just want to
reuse free space in swap partition.

I think you've just invented uswsusp.
                                                                        Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) 
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to