On Thu, 8 Dec 2016 02:22:55 +0100 Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> wrote: > TL;DR: these patches save 250 KB of memory, with more low-hanging > fruit ready to pick. > > While browsing through the lib/idr.c code, I noticed that the code at > the end of ida_get_new_above() probably doesn't work as intended: Most > users of ida use it via ida_simple_get(), and that starts by > unconditionally calling ida_pre_get(), ensuring that ida->idr has > 8==MAX_IDR_FREE idr_layers in its free list id_free. In the common > case, none (or at most one) of these get used during > ida_get_new_above(), and we only free one, leaving at least 6 (usually > 7) idr_layers in the free list. Please be aware of http://ozlabs.org/~akpm/mmots/broken-out/reimplement-idr-and-ida-using-the-radix-tree.patch http://lkml.kernel.org/r/1480369871-5271-68-git-send-email-mawilcox@xxxxxxxxxxxxxxxxx I expect we'll be merging patches 1-32 of that series into 4.10-rc1 and the above patch (#33) into 4.11-rc1. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
