On 10/13/20 2:49 PM, Rasmus Villemoes wrote: > On 13/10/2020 21.49, Jens Axboe wrote: >> On 10/13/20 1:46 PM, Linus Torvalds wrote: >>> On Mon, Oct 12, 2020 at 6:46 AM Jens Axboe <axboe@xxxxxxxxx> 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. > > Citation needed. There's lots of "pointer to const foo" stuff declared > as __read_mostly, but I can't find any objects that are themselves both > const and __read_mostly. Other than that io_op_defs and io_uring_fops now. You are right, they are all pointers, so not the same. I'll just revert the patch. -- Jens Axboe
