Messages in this thread |  | | From | (Andreas Schwab) | Subject | Re: Big mallocs, mmap sorrows and double buffering. | Date | 12 Feb 1997 11:21:31 +0100 |
| |
Matti Aarnio <matti.aarnio@tele.fi> writes:
|>> icp = (char *)mmap( 0, st.st_size, |>> PROT_READ, MAP_FILE | MAP_PRIVATE, ifd, 0);
|> Ouch! You need: MAP_FILE|MAP_SHARED |> You don't want a private copy of it!
Since PROT_WRITE is not set this is in effect a shared mapping (and Linux internally handles it like a shared mapping).
|>> ocp = (char *)mmap( 0, st.st_size, |>> PROT_WRITE, MAP_FILE | MAP_PRIVATE, ofd, 0);
|> No, you can't mmap() for writing the file.
Sure you can (if you use MAP_SHARED). -- Andreas Schwab "And now for something schwab@issan.informatik.uni-dortmund.de completely different"
|  |