On Mon, Jan 20, 2014 at 03:44:44AM +0000, Nicholas A. Bellinger wrote: > From: Kent Overstreet <k...@daterainc.com> > > This patch changes percpu_ida_alloc() + callers to accept task state > bitmask for prepare_to_wait() for code like target/iscsi that needs > it for interruptible sleep, that is provided in a subsequent patch. > > It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep > waiting for a new tag, or TASK_RUNNING when the caller cannot sleep, > and is forced to return a negative value when no tags are available. > > v2 changes: > - Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes > - Drop signal_pending_state() call
Urgh, you made me look at percpu_ida... steal_tags() does a for_each_cpus() with IRQs disabled. This mean you'll disable IRQs for multiple ticks on SGI class hardware. That is a _very_ long time indeed. Then there's alloc_global_tags() vs alloc_local_tags(), one gets an actual tag, while the other only moves tags about -- semantic mismatch. I do not get the comment near prepare to wait -- why does it matter if percpu_ida_free() flips a cpus_have_tags bit? Given I don't understand this comment, its hard for me to properly review the proposed patch series. Help? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
