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Tue, 4 Feb 2020 09:46:55 +0000 (UTC) Date: Tue, 4 Feb 2020 10:46:53 +0100 From: Oscar Salvador To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, x86@kernel.org, Andrew Morton , Michal Hocko , Pavel Tatashin , Dan Williams , Wei Yang Subject: Re: [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages() Message-ID: <20200204094652.GE6494@linux> References: <20191006085646.5768-1-david@redhat.com> <20191006085646.5768-11-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191006085646.5768-11-david@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, Oct 06, 2019 at 10:56:46AM +0200, David Hildenbrand wrote: > Let's drop the basically unused section stuff and simplify. > > Also, let's use a shorter variant to calculate the number of pages to > the next section boundary. > > Cc: Andrew Morton > Cc: Oscar Salvador > Cc: Michal Hocko > Cc: Pavel Tatashin > Cc: Dan Williams > Cc: Wei Yang > Signed-off-by: David Hildenbrand I have to confess that it took me while to wrap around my head with the new min() change, but looks ok: Reviewed-by: Oscar Salvador > --- > mm/memory_hotplug.c | 17 ++++++----------- > 1 file changed, 6 insertions(+), 11 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 843481bd507d..2275240cfa10 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -490,25 +490,20 @@ static void __remove_section(unsigned long pfn, unsigned long nr_pages, > void __remove_pages(unsigned long pfn, unsigned long nr_pages, > struct vmem_altmap *altmap) > { > + const unsigned long end_pfn = pfn + nr_pages; > + unsigned long cur_nr_pages; > unsigned long map_offset = 0; > - unsigned long nr, start_sec, end_sec; > > map_offset = vmem_altmap_offset(altmap); > > if (check_pfn_span(pfn, nr_pages, "remove")) > return; > > - start_sec = pfn_to_section_nr(pfn); > - end_sec = pfn_to_section_nr(pfn + nr_pages - 1); > - for (nr = start_sec; nr <= end_sec; nr++) { > - unsigned long pfns; > - > + for (; pfn < end_pfn; pfn += cur_nr_pages) { > cond_resched(); > - pfns = min(nr_pages, PAGES_PER_SECTION > - - (pfn & ~PAGE_SECTION_MASK)); > - __remove_section(pfn, pfns, map_offset, altmap); > - pfn += pfns; > - nr_pages -= pfns; > + /* Select all remaining pages up to the next section boundary */ > + cur_nr_pages = min(end_pfn - pfn, -(pfn | PAGE_SECTION_MASK)); > + __remove_section(pfn, cur_nr_pages, map_offset, altmap); > map_offset = 0; > } > } > -- > 2.21.0 > > -- Oscar Salvador SUSE L3