Buildresult: linus/um-defconfig/um-x86_64-gcc12 built on Jul 27, 10:48

kisskb

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Status:	OK
Date/Time:	Jul 27, 10:48
Duration:	0:00:36.111207
Builder:	ka4
Revision:	minmax: avoid overly complicated constant expressions in VM code (`3a7e02c040b130b5545e4b115aada7bacd80a2b6)`
Target:	linus/um-defconfig/um-x86_64-gcc12
Branch:	linus
Compiler:	um-x86_64-gcc12 (x86_64-linux-gcc.br_real (Buildroot 2021.11-4428-g6b6741b) 12.2.0 / GNU ld (GNU Binutils) 2.39)
Config:	defconfig (download)
Log:	Download original No warnings found in log. Full Log # git rev-parse -q --verify 3a7e02c040b130b5545e4b115aada7bacd80a2b6^{commit} 3a7e02c040b130b5545e4b115aada7bacd80a2b6 already have revision, skipping fetch # git checkout -q -f -B kisskb 3a7e02c040b130b5545e4b115aada7bacd80a2b6 # git clean -qxdf # < git log -1 # commit 3a7e02c040b130b5545e4b115aada7bacd80a2b6 # Author: Linus Torvalds <torvalds@linux-foundation.org> # Date: Fri Jul 26 15:32:27 2024 -0700 # # minmax: avoid overly complicated constant expressions in VM code # # The minmax infrastructure is overkill for simple constants, and can # cause huge expansions because those simple constants are then used by # other things. # # For example, 'pageblock_order' is a core VM constant, but because it was # implemented using 'min_t()' and all the type-checking that involves, it # actually expanded to something like 2.5kB of preprocessor noise. # # And when that simple constant was then used inside other expansions: # # #define pageblock_nr_pages (1UL << pageblock_order) # #define pageblock_start_pfn(pfn) ALIGN_DOWN((pfn), pageblock_nr_pages) # # and we then use that inside a 'max()' macro: # # case ISOLATE_SUCCESS: # update_cached = false; # last_migrated_pfn = max(cc->zone->zone_start_pfn, # pageblock_start_pfn(cc->migrate_pfn - 1)); # # the end result was that one statement expanding to 253kB in size. # # There are probably other cases of this, but this one case certainly # stood out. # # I've added 'MIN_T()' and 'MAX_T()' macros for this kind of "core simple # constant with specific type" use. These macros skip the type checking, # and as such need to be very sparingly used only for obvious cases that # have active issues like this. # # Reported-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> # Link: https://lore.kernel.org/all/36aa2cad-1db1-4abf-8dd2-fb20484aabc3@lucifer.local/ # Cc: David Laight <David.Laight@aculab.com> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/x86-64--glibc--bleeding-edge-2022.08-1/bin/x86_64-linux-gcc --version # < /opt/cross/kisskb/x86-64--glibc--bleeding-edge-2022.08-1/bin/x86_64-linux-ld --version # < git log --format=%s --max-count=1 3a7e02c040b130b5545e4b115aada7bacd80a2b6 # make -s -j 40 ARCH=um O=/kisskb/build/linus_defconfig_um-x86_64-gcc12 CROSS_COMPILE=/opt/cross/kisskb/x86-64--glibc--bleeding-edge-2022.08-1/bin/x86_64-linux- SUBARCH=x86_64 defconfig # < make -s -j 40 ARCH=um O=/kisskb/build/linus_defconfig_um-x86_64-gcc12 CROSS_COMPILE=/opt/cross/kisskb/x86-64--glibc--bleeding-edge-2022.08-1/bin/x86_64-linux- SUBARCH=x86_64 help # make -s -j 40 ARCH=um O=/kisskb/build/linus_defconfig_um-x86_64-gcc12 CROSS_COMPILE=/opt/cross/kisskb/x86-64--glibc--bleeding-edge-2022.08-1/bin/x86_64-linux- SUBARCH=x86_64 olddefconfig # make -s -j 40 ARCH=um O=/kisskb/build/linus_defconfig_um-x86_64-gcc12 CROSS_COMPILE=/opt/cross/kisskb/x86-64--glibc--bleeding-edge-2022.08-1/bin/x86_64-linux- SUBARCH=x86_64 LINK linux Completed OK # rm -rf /kisskb/build/linus_defconfig_um-x86_64-gcc12 # Build took: 0:00:36.111207

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