On 11/08/2016 11:16 AM, Logan Gunthorpe wrote:
Hi guys, We were looking at testing the new IO polling improvements and we built a kernel from the 'for-4.10/dio' (64ead7d) branch in linux-block. However this branch seems to cause hung tasks when booted. Most noticeably, dhclient seems to always hang as it tries to read from it's leases file, and that means networking does not work on the computers we tested on. Other tasks seemed to hang occasionally and randomly. We tested on two machines with radically different hardware but both running Debian Jessie. (One is a dual-socket server system with the root FS on an HDD and the other is an off the shelf commodity motherboard with root on an SSD.) We performed a bisect to find the culprit commit to be: [b685d3d65ac791406e0dfd8779cc9b3707fea5a3] block: treat REQ_FUA and REQ_PREFLUSH as synchronous I've attached a bisect log.
I don't think that's right. The version you ran has a bug in the stats code. Please update to the current for-4.10/dio branch (82a78cd682bf) and I think you'll have more luck. -- Jens Axboe -- 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
