On 06/27/16 at 04:21pm, Dave Young wrote: > Please ignore previous reply, I mistakenly send a broken mail without > subject, sorry about it. Resend the reply here. > > On 06/27/16 at 01:37pm, Thiago Jung Bauermann wrote: > > Am Dienstag, 28 Juni 2016, 00:19:48 schrieb Dave Young: > > > On 06/23/16 at 12:37pm, Thiago Jung Bauermann wrote: > > > > Am Donnerstag, 23 Juni 2016, 01:44:07 schrieb Dave Young: > > > > What is bad about the description of top_down? > > > It is not clear enough to me, I personally think the original one in > > > source code is better: > > > /* allocate from top of memory hole */ > > > > Actually I realized there's some discrepancy in how the x86 code uses > > top_down and how I need it to work in powerpc. This may be what is confusing > > about my comment and the existing comment. > > > > x86 always walks memory from bottom to top but if top_down is true, in each > > memory region it will allocate the memory hole in the highest address within > > that region. I don't know why it is done that way, though. > > I think we did not meaning to do this, considering kdump we have only > one crashkernel region for searching (crashk_res) so it is fine. > For kexec maybe changing the walking function to accept top_down is > reasonable. > > Ccing Vivek see if he can remember something.. > > > > > On powerpc, the memory walk itself should be from top to bottom, as well as > > the memory hole allocation within each memory region. What is the particular reason in powerpc for a mandatory top to bottom walking? > > > > Should I add a separate top_down argument to kexec_locate_mem_hole to > > control if the memory walk should be from top to bottom, and then the > > bottom_up member of struct kexec_buf controls where inside each memory > > region the memory hole will be allocated? Using one argument for both sounds more reasonable than using a separate argument for memory walk.. Thanks Dave
