# git rev-parse -q --verify 8008293888188c3923f5bd8a69370dae25ed14e5^{commit}
8008293888188c3923f5bd8a69370dae25ed14e5
already have revision, skipping fetch
# git checkout -q -f -B kisskb 8008293888188c3923f5bd8a69370dae25ed14e5
# git clean -qxdf
# < git log -1
# commit 8008293888188c3923f5bd8a69370dae25ed14e5
# Author: Mel Gorman <mgorman@techsingularity.net>
# Date:   Fri Dec 31 13:10:09 2021 -0800
# 
#     mm: vmscan: reduce throttling due to a failure to make progress -fix
#     
#     Hugh Dickins reported the following
#     
#             My tmpfs swapping load (tweaked to use huge pages more heavily
#             than in real life) is far from being a realistic load: but it was
#             notably slowed down by your throttling mods in 5.16-rc, and this
#             patch makes it well again - thanks.
#     
#             But: it very quickly hit NULL pointer until I changed that last
#             line to
#     
#             if (first_pgdat)
#                     consider_reclaim_throttle(first_pgdat, sc);
#     
#     The likely issue is that huge pages are a major component of the test
#     workload.  When this is the case, first_pgdat may never get set if
#     compaction is ready to continue due to this check
#     
#             if (IS_ENABLED(CONFIG_COMPACTION) &&
#                 sc->order > PAGE_ALLOC_COSTLY_ORDER &&
#                 compaction_ready(zone, sc)) {
#                     sc->compaction_ready = true;
#                     continue;
#             }
#     
#     If this was true for every zone in the zonelist, first_pgdat would never
#     get set resulting in a NULL pointer exception.
#     
#     Link: https://lkml.kernel.org/r/20211209095453.GM3366@techsingularity.net
#     Fixes: 1b4e3f26f9f75 ("mm: vmscan: Reduce throttling due to a failure to make progress")
#     Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
#     Reported-by: Hugh Dickins <hughd@google.com>
#     Cc: Michal Hocko <mhocko@suse.com>
#     Cc: Vlastimil Babka <vbabka@suse.cz>
#     Cc: Rik van Riel <riel@surriel.com>
#     Cc: Mike Galbraith <efault@gmx.de>
#     Cc: Darrick J. Wong <djwong@kernel.org>
#     Cc: Shakeel Butt <shakeelb@google.com>
#     Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 8008293888188c3923f5bd8a69370dae25ed14e5
# < make -s -j 32 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  44x/fsp2_defconfig
# < make -s -j 32 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 32 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 32 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
Completed OK
# rm -rf /kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5
# Build took: 0:01:29.152606