From: Oscar Salvador <osalvador@suse.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
Logan Gunthorpe <logang@deltatee.com>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Linux MM <linux-mm@kvack.org>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v9 08/12] mm/sparsemem: Support sub-section hotplug
Date: Fri, 07 Jun 2019 23:41:27 +0200 [thread overview]
Message-ID: <1559943687.3141.8.camel@suse.de> (raw)
In-Reply-To: <CAPcyv4hgmjUvA0+uMWYJibmgSWtoLw7zM-jFuP7eRdU2xyVxOw@mail.gmail.com>
On Fri, 2019-06-07 at 08:38 -0700, Dan Williams wrote:
> I don't know, but I can't imagine it would because it's much easier
> to
> do mem_map relative translations by simple PAGE_OFFSET arithmetic.
Yeah, I guess so.
> No worries, its a valid question. The bitmap dance is still valid it
> will just happen on section boundaries instead of subsection. If
> anything breaks that's beneficial additional testing that we got from
> the SPARSEMEM sub-case for the SPARSEMEM_VMEMMAP superset-case.
> That's
> the gain for keeping them unified, what's the practical gain from
> hiding this bit manipulation from the SPARSEMEM case?
It is just that I thought that we might benefit from not doing extra
work if not needed (bitmap dance) in SPARSEMEM case.
But given that 1) hot-add/hot-remove paths are not hot paths, it does
not really matter 2) and that having all cases unified in one function
make sense too, spreading the work in more functions might be sub-
optimal.
I guess I could justfiy it in case both activate/deactive functions
would look convulated, but it is not the case here.
I just took another look to check that I did not miss anything.
It looks quite nice and compact IMO:
Reviewed-by: Oscar Salvador <osalvador@suse.de>
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2019-06-07 21:41 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-05 21:57 [PATCH v9 00/12] mm: Sub-section memory hotplug support Dan Williams
2019-06-05 21:57 ` [PATCH v9 01/12] mm/sparsemem: Introduce struct mem_section_usage Dan Williams
2019-06-06 17:34 ` Oscar Salvador
2019-06-16 13:11 ` Wei Yang
2019-06-18 21:56 ` Dan Williams
2019-06-19 2:13 ` Wei Yang
2019-06-05 21:57 ` [PATCH v9 02/12] mm/sparsemem: Add helpers track active portions of a section at boot Dan Williams
2019-06-06 16:55 ` Oscar Salvador
2019-06-17 22:21 ` Wei Yang
2019-06-17 22:32 ` Dan Williams
2019-06-18 1:03 ` Wei Yang
2019-06-19 3:15 ` Dan Williams
2019-06-05 21:58 ` [PATCH v9 03/12] mm/hotplug: Prepare shrink_{zone, pgdat}_span for sub-section removal Dan Williams
2019-06-18 1:42 ` Wei Yang
2019-06-19 3:40 ` Dan Williams
2019-06-05 21:58 ` [PATCH v9 04/12] mm/sparsemem: Convert kmalloc_section_memmap() to populate_section_memmap() Dan Williams
2019-06-06 17:02 ` Oscar Salvador
2019-06-16 6:06 ` Aneesh Kumar K.V
2019-06-05 21:58 ` [PATCH v9 05/12] mm/hotplug: Kill is_dev_zone() usage in __remove_pages() Dan Williams
2019-06-05 21:58 ` [PATCH v9 06/12] mm: Kill is_dev_zone() helper Dan Williams
2019-06-18 3:35 ` Wei Yang
2019-06-05 21:58 ` [PATCH v9 07/12] mm/sparsemem: Prepare for sub-section ranges Dan Williams
2019-06-06 17:21 ` Oscar Salvador
2019-06-06 18:16 ` Dan Williams
2019-06-14 8:39 ` David Hildenbrand
2019-06-05 21:58 ` [PATCH v9 08/12] mm/sparsemem: Support sub-section hotplug Dan Williams
2019-06-07 8:33 ` Oscar Salvador
2019-06-07 15:38 ` Dan Williams
2019-06-07 21:41 ` Oscar Salvador [this message]
2019-06-05 21:58 ` [PATCH v9 09/12] mm: Document ZONE_DEVICE memory-model implications Dan Williams
2019-06-05 21:58 ` [PATCH v9 10/12] mm/devm_memremap_pages: Enable sub-section remap Dan Williams
2019-06-07 8:56 ` Oscar Salvador
2019-06-16 7:49 ` Aneesh Kumar K.V
2019-06-05 21:58 ` [PATCH v9 11/12] libnvdimm/pfn: Fix fsdax-mode namespace info-block zero-fields Dan Williams
2019-06-06 21:46 ` Andrew Morton
2019-06-06 22:06 ` Dan Williams
2019-06-07 19:54 ` Andrew Morton
2019-06-07 20:09 ` Dan Williams
2019-06-12 9:41 ` Aneesh Kumar K.V
2019-06-05 21:59 ` [PATCH v9 12/12] libnvdimm/pfn: Stop padding pmem namespaces to section alignment Dan Williams
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