On Wed, 21 Mar 2012 12:31:47 +0800 Shaohua Li <shli@xxxxxxxxxx> wrote: > But on > the other hand, if user doesn't explictly enable discard, why enable > it? Like fs, we didn't do runtime discard and only run trim occasionally > since discard is slow. This. Neither the swapon manpage nor the SWAP_FLAG_DISCARD comment nor .c code comments nor the 339944663 changelog explain why we do a single discard at swapon() time and then never again. It sure *looks* like a bug. If it isn't then some explanation is sorely needed. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>