On Tue, Apr 06, 2021 at 09:44:16AM +0300, Leon Romanovsky wrote: > On Mon, Apr 05, 2021 at 07:15:32PM -0300, Jason Gunthorpe wrote: > > On Mon, Apr 05, 2021 at 04:09:39PM +0300, Gal Pressman wrote: > > > On 05/04/2021 15:39, Leon Romanovsky wrote: > > > > On Mon, Apr 05, 2021 at 03:15:18PM +0300, Gal Pressman wrote: > > > >> On 05/04/2021 14:57, Leon Romanovsky wrote: > > > >>> On Mon, Apr 05, 2021 at 02:47:21PM +0300, Gal Pressman wrote: > > > >>>> The new attribute indicates that the kernel copies DMA pages on fork, > > > >>>> hence libibverbs' fork support through madvise and MADV_DONTFORK is not > > > >>>> needed. > > > >>>> > > > >>>> The introduced attribute is always reported as supported since the > > > >>>> kernel has the patch that added the copy-on-fork behavior. This allows > > > >>>> the userspace library to identify older vs newer kernel versions. > > > >>>> Extra care should be taken when backporting this patch as it relies on > > > >>>> the fact that the copy-on-fork patch is merged, hence no check for > > > >>>> support is added. > > > >>> > > > >>> Please be more specific, add SHA-1 of that patch and wrote the same > > > >>> comment near "err = nla_put_u8(msg, RDMA_NLDEV_SYS_ATTR_COPY_ON_FORK, > > > >>> 1);" line. > > > >>> > > > >>> Thanks > > > >> > > > >> Should I put the original commit here? There were quite a lot of bug fixes and > > > >> followups that are required. > > > > > > > > IMHO, the last commit SHA will be enough, the one that has working > > > > functionality from your POV. > > > > > > OK, so that would be: > > > 4eae4efa2c29 ("hugetlb: do early cow when page pinned on src mm") > > > > No, lets put them all > > The more data the better chance that it will be missed. > It is much saner to add last commit. I don't know, there is alot of automation here we need to ensure that none of it triggers unless all the required commits are present. I would list all the tops of all the 'fixes' chains. > > And email Sasha to see if there is a magic text we can add to prevent > > auto backporting > > Don't add Fixes, maybe? Then it randomly AI matches on the commit text and we loose even the protection of the fixes lines Jason