On Fri, 20 Apr 2007, Ulrich Drepper wrote: > > Just for reference: the MADV_CURRENT behavior is to throw away data in > the range.
Not exactly. The Linux MADV_DONTNEED never throws away data from a PROT_WRITE,MAP_SHARED mapping (or shm) - it propagates the dirty bit, the page will eventually get written out to file, and can be retrieved later by subsequent access. But the Linux MADV_DONTNEED does throw away data from a PROT_WRITE,MAP_PRIVATE mapping (or brk or stack) - those changes are discarded, and a subsequent access will revert to zeroes or the underlying mapped file. Been like that since before 2.4.0. > The POSIX_MADV_DONTNEED behavior is to never lose data. > I.e., file backed data is written back, anon data is at most swapped > out. - 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/
