On Fri, Nov 04, 2016 at 04:28:05PM -0700, Jeremy Allison wrote: > I don't suppose ext4 has a negative cache for lookups ? That would > certainly help the linear search case on lookup miss. The dcache caches negative results, so as long as the lookup miss is for the same non-existing file name, that's not a problem. The issue will be if someone is using Makefile with default rules, say, and Makefile is checking for foo.y, foo.l, foo.C, etc. for each object file, there could be a fairly large number of failed lookups that might require O(n) lookups. Eventually all of these will be cached, yes, but it could be a large number of negative dentry caches. However, I'm not sure I care; no self-respecting programmer should be using a case-insensitive file system, so in practice, I'm not sure it matters all that much.... - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
