>> I have drop_caches in my suspend-to-disk script so that the hibernation >> image is kept at minimum and suspend times are as small as possible. > > hm, that sounds smart. > >> Would that be a valid use-case? > > I'd say so, unless we change the kernel to do that internally. We do > have the hibernation-specific shrink_all_memory() in the vmscan code. > We didn't see fit to document _why_ that exists, but IIRC it's there to > create enough free memory for hibernation to be able to successfully > complete, but no more. shrink_all_memory() drop minimum memory to be needed from hibernation. that's trade off matter. - drop all page cache pros. speed up hibernation time cons. after go back from hibernation, system works very slow a while until system will get enough file cache. - drop minimum page cache pros. system works quickly when go back from hibernation. cons. relative large hibernation time So, I'm not fun change hibernation default. hmmm... Does adding tracepint instead of printk makes sense? -- 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>