Hi Eric On 01/22/2018 12:43 AM, Eric Dumazet wrote: > On Sun, 2018-01-21 at 18:24 +0200, Tariq Toukan wrote: >> >> On 21/01/2018 11:31 AM, Tariq Toukan wrote: >>> >>> >>> On 19/01/2018 5:49 PM, Eric Dumazet wrote: >>>> On Fri, 2018-01-19 at 23:16 +0800, jianchao.wang wrote: >>>>> Hi Tariq >>>>> >>>>> Very sad that the crash was reproduced again after applied the patch. >> >> Memory barriers vary for different Archs, can you please share more >> details regarding arch and repro steps? > > Yeah, mlx4 NICs in Google fleet receive trillions of packets per > second, and we never noticed an issue. > > Although we are using a slightly different driver, using order-0 pages > and fast pages recycling. > > The driver we use will will set the page reference count to (size of pages)/stride, the pages will be freed by networking stack when the reference become zero, and the order-3 pages maybe allocated soon, this give NIC device a chance to corrupt the pages which have been allocated by others, such as slab. In the current version with order-0 and page recycling, maybe the corruption occurred on the inbound packets sometimes and just cause some bad and invalid packets which will be dropped.
Thanks Jianchao
