re: Big mallocs, mmap sorrows and double buffering. (fwd)

Jim Nance (
Tue, 11 Feb 1997 08:42:09 -0500 (EST)

Forwarded message:

> I have just tried mmap() & memcpy() to copy a 19Mb file on a 24Mb ram
> system. It started thrashing quite heavily but completed without
> hanging.
> Sorrow! Woe! Misery! I tried it on a 38Mb file and it said
> "output memory map : out of memory."
> Is that a mmem() bug perhaps? Or has too many page descriptors
> been created to fit into physical memory?

Make sure you are using the MAP_SHARED option to mmap. It sounds like
you might be using MAP_PRIVATE.