From: Cong Wang <xiyou.wangc...@gmail.com> Date: Mon, 5 Nov 2012 16:41:49 +0800
> On Tue, Oct 30, 2012 at 10:24 PM, Stephen Hemminger > <shemmin...@vyatta.com> wrote: >> On Tue, 30 Oct 2012 07:00:56 +0100 >> Paolo Valente <paolo.vale...@unimore.it> wrote: >> >>> Hi, >>> if the max packet size for some class (configured through tc) is >>> violated by the actual size of the packets of that class, then QFQ >>> would not schedule classes correctly, and the data structures >>> implementing the bucket lists may get corrupted. This problem occurs >>> with TSO/GSO even if the max packet size is set to the MTU, and is, >>> e.g., the cause of the failure reported in [1]. Two patches have been >>> proposed to solve this problem in [2], one of them is a preliminary >>> version of this patch. >>> >>> This patch addresses the above issues by: 1) setting QFQ parameters to >>> proper values for supporting TSO/GSO (in particular, setting the >>> maximum possible packet size to 64KB), 2) automatically increasing the >>> max packet size for a class, lmax, when a packet with a larger size >>> than the current value of lmax arrives. >>> >>> The drawback of the first point is that the maximum weight for a class >>> is now limited to 4096, which is equal to 1/16 of the maximum weight >>> sum. >>> >>> Finally, this patch also forcibly caps the timestamps of a class if >>> they are too high to be stored in the bucket list. This capping, taken >>> from QFQ+ [3], handles the unfrequent case described in the comment to >>> the function slot_insert. >>> >>> [1] http://marc.info/?l=linux-netdev&m=134968777902077&w=2 >>> [2] http://marc.info/?l=linux-netdev&m=135096573507936&w=2 >>> [3] http://marc.info/?l=linux-netdev&m=134902691421670&w=2 >>> >>> Signed-off-by: Paolo Valente <paolo.vale...@unimore.it> >>> Tested-by: Cong Wang <amw...@redhat.com> >> >> Acked-by: Stephen Hemminger <shemmin...@vyatta.com> > > > David, could you take this patch? Stephen acked it. It's "RFC" so it needs to be explicitly reposted. -- 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/
