On Tue, 25 Mar 2025 05:15:10 -0700 (PDT) Steven Rostedt <[email protected]> wrote:
> How important is it for you to build 64 bit kernels > on 32 bit machines? Yeah I don't disagree at all, it is a fairly idiosyncratic thing to do. There are some historical and business justifications for still building 32-bit in the first place, but until we deduplicate the kernel build, we will continue to have this issue. > One solution may be to simply disable > mcount sorting at build time when it is detected that the host is 32 bit > and the target is 64 bit. We are currently doing this. I imagine the performance difference is trivial but if we can sort at build time, we might as well. I have a fairly simple alternate solution that isn't backporting all of those patches. The core idea is to introduce another macro, parse_addr, that is defined as # define parse_addr(buf) strtoull(buf, NULL, 16) when SORTTABLE_64 is defined and # define parse_addr(buf) strtoul(buf, NULL, 16) when it isn't. Seems like a fair thing to do considering unsigned long long is guaranteed to be at least 64-bit and unsigned long is guaranteed to be at least 32-bit. I can post the patch in a stable- thread. Sahil On Tue, Mar 25, 2025 at 7:15 AM Steven Rostedt <[email protected]> wrote: > > On Tue, 25 Mar 2025 07:58:36 -0400 > Greg KH <[email protected]> wrote: > > > It's up to the maintainer of the subsytem as to what they wish to see > > happen. I will always defer to them as they are the ones that have to > > deal with emails from users :) > > Thanks Greg for the reply. > > Now bringing the question to Sahil. > > This looks to be broken in 5.17 (when the mcount sorting was added). And > you are now using 6.12. How important is it for you to build 64 bit kernels > on 32 bit machines? > > Nobody noticed this for a long time. One solution may be to simply disable > mcount sorting at build time when it is detected that the host is 32 bit > and the target is 64 bit. I don't know how easy it is to detect that at > build time, as it needs to unset a kernel CONFIG option. Perhaps Kconfig > can detect that? > > -- Steve
