On Thu, May 28, 2015 at 07:24:34AM -0400, Jeff Layton wrote: > > > 1) this is not done under a lock, so the non-atomic ++/-- is racy if > > > there are multiple swapons/swapoffs running concurrently on the same > > > xprt. Shouldn't those use an atomic? > > > > > > > It would be more appropriate to use atomics. It's a long time ago but I > > doubt I considered the possibility of multiple swapons racing at the > > time of implementation. Activation is typically a serialised task run > > from init. > > > > > 2) on enable, "swapper" is incremented and memalloc is set on the > > > socket. Do we need to do xs_set_memalloc every time swapon is called, > > > or only on a 0->1 swapper transition. > > > > > > > Every time because the static_key_slow_inc call is for the total number > > of connections. > > > > That still seems wrong. The static_key would still be active even if > you just did it once per xprt. > True. As long as it is active while one swapfile exists then it's good. -- Mel Gorman SUSE Labs -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>