Messages in this thread | | | Date | Thu, 28 Jun 2018 15:12:52 +0200 | From | Oscar Salvador <> | Subject | Re: [PATCH v6 4/5] mm/sparse: Optimize memmap allocation during sparse_init() |
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On Thu, Jun 28, 2018 at 08:12:04AM -0400, Pavel Tatashin wrote: > > > + if (nr_consumed_maps >= nr_present_sections) { > > > + pr_err("nr_consumed_maps goes beyond nr_present_sections\n"); > > > + break; > > > + } > > > > Hi Baoquan, > > > > I am sure I am missing something here, but is this check really needed? > > > > I mean, for_each_present_section_nr() only returns the section nr if the section > > has been marked as SECTION_MARKED_PRESENT. > > That happens in memory_present(), where now we also increment nr_present_sections whenever > > we find a present section. > > > > So, for_each_present_section_nr() should return the same nr of section as nr_present_sections. > > Since we only increment nr_consumed_maps once in the loop, I am not so sure we can > > go beyond nr_present_sections. > > > > Did I overlook something? > > You did not, this is basically a safety check. A BUG_ON() would be > better here. As, this something that should really not happening, and > would mean a bug in the current project.
I think we would be better off having a BUG_ON() there. Otherwise the system can go sideways later on.
-- Oscar Salvador SUSE L3
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