Hi Pekka, On 08/13/2013 02:01 PM, Pekka Enberg wrote: > On 8/6/13 2:36 PM, Bob Liu wrote: >> Zcache could be ineffective if the compressed memory pool is full with >> compressed inactive file pages and most of them will be never used again. >> >> So we pick up pages from active file list only, those pages would >> probably be >> accessed again. Compress them in memory can reduce the latency >> significantly >> compared with rereading from disk. >> >> When a file page is shrinked from active file list to inactive file list, >> PageActive flag is also cleared. >> So adding an extra WasActive page flag for zcache to know whether the >> file page >> was shrinked from the active list. >> >> Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx> > Thank you so much for your review! > Using a page flag for this seems like an ugly hack to me. > Can we rearrange the code so that vmscan notifies zcache > *before* the active page flag is cleared...? Yep, adding a page flag is not a good idea. I'm looking at whether there is other way to notify zcache. BTW: Could you please give some feedback too about other zcache patches? > > Pekka -- Regards, -Bob -- 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>