On Wed, Sep 2, 2015 at 3:50 PM, Jens Axboe <ax...@fb.com> wrote: > On 09/02/2015 04:41 PM, Jens Axboe wrote: >> >> On 09/02/2015 04:34 PM, Linus Torvalds wrote: >>> >>> Jens, >>> >>> On Wed, Sep 2, 2015 at 9:58 AM, Jens Axboe <ax...@fb.com> wrote: >>>> >>>> >>>> This pull request contains a set of scatter-gather related changes/fixes >>>> for 4.3. It contains: >>> >>> >>> This results in several new and annoying warnings. They may all be ok >>> code, but they are very distracting. Please stop introducing new >>> warnings to the build, because by now most of the warnings I see come >>> from the block layer. >>> >>> block/blk-merge.c: In function ‘blk_queue_split’: >>> include/linux/blkdev.h:1368:21: warning: ‘bvprv.bv_offset’ may be >>> used uninitialized in this function [-Wmaybe-uninitialized] >>> ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); >>> >>> (it gives this for bv_len too). The reason seems to be that disgusting >>> situation where "bvprv" is uninitiatlized unless "split" is true, and >>> the code looks like it is correct, but the compiler clearly has a hard >>> time seeing it. It took me a while too, so I can't really blame it. >>> >>> Either initialize bvprv to something explicit, or make the code clear >>> enough that the compiler can see that it is never used uninitialized. >>> Because those compiler warnings are sometimes real, and we can't just >>> ignore them. >>> >>> There was another type-based warning introduced by your core block >>> pull (size_t vs unsigned int). >> >> >> I think it's a repeat offender that got reintroduced. I'll fix it up. > > > This seems to make it happier. Will go out later in the merge window. > > http://git.kernel.dk/cgit/linux-block/commit/?h=for-linus&id=5014c311baa2b21384321fa4a9f617a92e3e56f0
Thanks Jens. I didn't see these warnings with gcc 4.8.4. What gcc version did you use or need to turn on some config option to see the warning? -- 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/
