On Mon, Jan 26, 2015 at 02:28:33PM -0600, Christoph Lameter wrote: > On Mon, 26 Jan 2015, Vladimir Davydov wrote: > > > Right, but I just don't see why a subsystem using a kmem_cache would > > need to check whether there are any objects left in the cache. I mean, > > it should somehow keep track of the objects it's allocated anyway, e.g. > > by linking them in a list. That means it must already have a way to > > check if it is safe to destroy its cache or not. > > The acpi subsystem did that at some point. > > > Suppose we leave the return value as is. A subsystem, right before going > > to destroy a cache, calls kmem_cache_shrink, which returns 1 (slab is > > not empty). What is it supposed to do then? > > That is up to the subsystem. If it has a means of tracking down the > missing object then it can deal with it. If not then it cannot shutdown > the cache and do a proper recovery action. Hmm, we could make kmem_cache_destroy return EBUSY for the purpose. However, since it spits warnings on failure, which is reasonable, we have this check in kmem_cache_shrink... Anyways, I see your point now, thank you for pointing it out. I will fix SLUB's __kmem_cache_shrink retval instead of removing it altogether in the next iteration. Thanks, Vladimir -- 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>