Messages in this thread | | | Date | Tue, 19 Feb 2019 12:04:00 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 14/20] mm: Make hibernate handle unmapped pages |
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On Mon, Jan 28, 2019 at 04:34:16PM -0800, Rick Edgecombe wrote: > For architectures with CONFIG_ARCH_HAS_SET_ALIAS, pages can be unmapped > briefly on the directmap, even when CONFIG_DEBUG_PAGEALLOC is not > configured. So this changes kernel_map_pages and kernel_page_present to be
s/this changes/change/
From Documentation/process/submitting-patches.rst:
"Describe your changes in imperative mood, e.g. "make xyzzy do frotz" instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy to do frotz", as if you are giving orders to the codebase to change its behaviour."
Also, please end function names with parentheses.
> defined when CONFIG_ARCH_HAS_SET_ALIAS is defined as well. It also changes > places (page_alloc.c) where those functions are assumed to only be > implemented when CONFIG_DEBUG_PAGEALLOC is defined.
The commit message doesn't need to say "what" you're doing - that should be obvious from the diff below. It should rather say "why" you're doing it.
> So now when CONFIG_ARCH_HAS_SET_ALIAS=y, hibernate will handle not present > page when saving. Previously this was already done when
pages
> CONFIG_DEBUG_PAGEALLOC was configured. It does not appear to have a big > hibernating performance impact.
Comment over safe_copy_page() needs updating I guess.
> Before: > [ 4.670938] PM: Wrote 171996 kbytes in 0.21 seconds (819.02 MB/s) > > After: > [ 4.504714] PM: Wrote 178932 kbytes in 0.22 seconds (813.32 MB/s)
IINM, that's like 1734 pages more. How am I to understand this number?
Code has called set_alias_nv_noflush() on them and safe_copy_page() now maps them one by one to copy them to the hibernation image?
Thx.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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