forked from luck/tmp_suning_uos_patched
d7deea31ed
[ Upstream commit 470c61d70299b1826f56ff5fede10786798e3c14 ] setup_per_zone_lowmem_reserve() iterates through each zone setting zone->lowmem_reserve[j] = 0 (where j is the zone's index) then iterates backwards through all preceding zones, setting lower_zone->lowmem_reserve[j] = sum(managed pages of higher zones) / lowmem_reserve_ratio[idx] for each (where idx is the lower zone's index). If the lower zone has no managed pages or its ratio is 0 then all of its lowmem_reserve[] entries are effectively zeroed. As these arrays are only assigned here and all lowmem_reserve[] entries for index < this zone's index are implicitly assumed to be 0 (as these are specifically output in show_free_areas() and zoneinfo_show_print() for example) there is no need to additionally zero index == this zone's index too. This patch avoids zeroing unnecessarily. Rather than iterating through zones and setting lowmem_reserve[j] for each lower zone this patch reverse the process and populates each zone's lowmem_reserve[] values in ascending order. This clarifies what is going on especially in the case of zero managed pages or ratio which is now explicitly shown to clear these values. Link: https://lkml.kernel.org/r/20201129162758.115907-1-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.