On Wed, Jul 22, 2020 at 12:57 PM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote: > > Pingfan Liu <kernelfans@xxxxxxxxx> writes: > > A bug is observed on pseries by taking the following steps on rhel: > ^ > RHEL > > I assume it happens on mainline too? Yes, it does. > [...] > > diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c > > index 1a3ac3b..def8cb3f 100644 > > --- a/arch/powerpc/platforms/pseries/hotplug-memory.c > > +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c > > @@ -372,6 +372,7 @@ static int dlpar_remove_lmb(struct drmem_lmb *lmb) > > invalidate_lmb_associativity_index(lmb); > > lmb_clear_nid(lmb); > > lmb->flags &= ~DRCONF_MEM_ASSIGNED; > > + drmem_update_dt(); > > No error checking? Hmm, here should be a more careful design. Please see the comment at the end. > > > __remove_memory(nid, base_addr, block_sz); > > > > @@ -607,6 +608,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb) > > > > lmb_set_nid(lmb); > > lmb->flags |= DRCONF_MEM_ASSIGNED; > > + drmem_update_dt(); > > And here .. > > > > block_sz = memory_block_size_bytes(); > > > > @@ -625,6 +627,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb) > > invalidate_lmb_associativity_index(lmb); > > lmb_clear_nid(lmb); > > lmb->flags &= ~DRCONF_MEM_ASSIGNED; > > + drmem_update_dt(); > > > And here .. > > > __remove_memory(nid, base_addr, block_sz); > > } > > @@ -877,9 +880,6 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog) > > break; > > } > > > > - if (!rc) > > - rc = drmem_update_dt(); > > - > > unlock_device_hotplug(); > > return rc; > > Whereas previously we did check it. drmem_update_dt() fails iff allocating memory fail. And in the failed case, even the original code does not roll back the effect of __add_memory()/__remove_memory(). And I plan to do the following in V4: if drmem_update_dt() fails in dlpar_add_lmb(), then bails out immediately. Thanks, Pingfan _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
