On 12/29/23 at 12:10pm, Andrew Morton wrote: > On Sat, 16 Dec 2023 11:31:04 +0800 Baoquan He <bhe@xxxxxxxxxx> wrote: > > > > > Imagine we have a crashkernel region 256M reserved under 4G, say [2G, 2G+256M]. > > > > Then after excluding the 256M from a region, it should stop. But now, this patch > > > > will make it continue scanning. Not sure if it's all in my mind. > > > > > > Hi Baoquan, > > > > > > Thank you for such a detailed reply. Now I finally understand why the code is > > > written this way. > > > > > > However, if we can guarantee its correctness, wouldn't it be better to use the > > > generic region removing logic? At least it is more concise and clear, and other > > > people reading this code for the first time wouldn't get confused like me. > > > > > > As for your concern about the while loop, I think it wouldn't affect performance > > > much because the total number of loops is small. > > > > Well, see below kexec-tools commit, you wouldn't say that. And when you > > understand the code, you will feel a little uncomfortable about the > > sustaining useless scanning. At least, we should stop scanning after > > needed exluding is done. > > > > Or, we may need add a generic region removing function so that it > > can be shared, e.g e820 memory region removing, memblock region removing. > > Otherwise, I can't see why a specific region excluding need a generic > > region removing function. > > So where do we now stand on this patchset? The patch 1 and 2 are good clean up. The patch 3 plus below one, the entire is a good code improvement patch. [PATCH] crash_core: optimize crash_exclude_mem_range() https://lore.kernel.org/all/20231219163418.108591-1-ytcoode@xxxxxxxxx/T/#u _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
