Tom Rini <trini@xxxxxx> writes: > On 04/28/2013 10:59 PM, Rusty Russell wrote: >> Tom Rini <trini@xxxxxx> writes: >> >>> Recent gcc's may place functions into the .text.unlikely section and we >>> need to check this section as well for section mismatches now otherwise >>> we may have false negatives for this test. >> >> Hmm, I don't think it's all that recent, is it? I can find it back to >> gcc 4.0.4: >> >> `-freorder-functions' >> Reorder functions in the object file in order to improve code >> locality. This is implemented by using special subsections >> `.text.hot' for most frequently executed functions and >> `.text.unlikely' for unlikely executed functions. Reordering is >> done by the linker so object file format must support named >> sections and linker must place them in a reasonable way. >> >> Also profile feedback must be available in to make this option >> effective. See `-fprofile-arcs' for details. >> >> Enabled at levels `-O2', `-O3', `-Os'. >> >> The comment is the same in in gcc 4.7. >> >> So is your real issue that this section is generated with >> -fprofile-arcs, or has something changed with gcc 4.8, or...? > > I've started seeing this with Linaro based 4.7 toolchains. I can go > back through their releases and see when it starts showing up there if > it helps. I didn't add .text.hot as I didn't have that section at all, > fwiw. Weird, did you turn on CONFIG_GCOV_KERNEL? AFAICT you shouldn't see this section without that. Thanks, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
