On Tue, Oct 13, 2020 at 01:49:01PM -0600, Jens Axboe wrote: > On 10/13/20 1:46 PM, Linus Torvalds wrote: > > On Mon, Oct 12, 2020 at 6:46 AM Jens Axboe <ax...@kernel.dk> wrote: > >> > >> Here are the io_uring updates for 5.10. > > > > Very strange. My clang build gives a warning I've never seen before: > > > > /tmp/io_uring-dd40c4.s:26476: Warning: ignoring changed section > > attributes for .data..read_mostly > > > > and looking at what clang generates for the *.s file, it seems to be > > the "section" line in: > > > > .type io_op_defs,@object # @io_op_defs > > .section .data..read_mostly,"a",@progbits > > .p2align 4 > > > > I think it's the combination of "const" and "__read_mostly". > > > > I think the warning is sensible: how can a piece of data be both > > "const" and "__read_mostly"? If it's "const", then it's not "mostly" > > read - it had better be _always_ read. > > > > I'm letting it go, and I've pulled this (gcc doesn't complain), but > > please have a look. > > Huh weird, I'll take a look. FWIW, the construct isn't unique across > the kernel. > > What clang are you using? > > -- > Jens Axboe >
If const and non-const __read_mostly appeared in the same file, both gcc and clang would give errors.
