Hello, On Mon, Feb 01, 2016 at 11:12:46PM +0100, Paolo Valente wrote: > From: Arianna Avanzini <avanzini.arianna@xxxxxxxxx> > > Complete support for full hierarchical scheduling, with a cgroups > interface. The name of the added policy is bfq. > > Weights can be assigned explicitly to groups and processes through the > cgroups interface, differently from what happens, for single > processes, if the cgroups interface is not used (as explained in the > description of the previous patch). In particular, since each node has > a full scheduler, each group can be assigned its own weight. * It'd be great if how cgroup support is achieved is better documented. * How's writeback handled? * After all patches are applied, both CONFIG_BFQ_GROUP_IOSCHED and CONFIG_CFQ_GROUP_IOSCHED exist. * The default weight and weight range don't seem to follow the defined interface on the v2 hierarchy. The default value should be 100. * With all patches applied, booting triggers a RCU context warning. Please build with lockdep and RCU debugging turned on and fix the issue. * I was testing on the v2 hierarchy with two top-level cgroups one hosting sequential workload and the other completely random. While they eventually converged to a reasonable state, starting up the sequential workload while the random workload was running was extremely slow. It crawled for quite a while. * And "echo 100 > io.weight" hung the writing process. Thanks. -- tejun -- 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
