Re: [PATCH v2 4/4] mm: Remove managed_page_count spinlock

From: kbuild test robot
Date: Wed Nov 07 2018 - 16:28:18 EST

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Hi Arun,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v4.20-rc1 next-20181107]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Arun-KS/mm-Fix-multiple-evaluvations-of-totalram_pages-and-managed_pages/20181108-025657
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64

All errors (new ones prefixed by >>):

>> mm/kasan/quarantine.c:239:23: error: not addressable
>> mm/kasan/quarantine.c:239:23: error: not addressable
In file included from include/asm-generic/bug.h:5:0,
from arch/x86/include/asm/bug.h:47,
from include/linux/bug.h:5,
from include/linux/mmdebug.h:5,
from include/linux/gfp.h:5,
from mm/kasan/quarantine.c:20:
mm/kasan/quarantine.c: In function 'quarantine_reduce':
include/linux/compiler.h:246:20: error: lvalue required as unary '&' operand
__read_once_size(&(x), __u.__c, sizeof(x)); \
^
include/linux/compiler.h:252:22: note: in expansion of macro '__READ_ONCE'
#define READ_ONCE(x) __READ_ONCE(x, 1)
^~~~~~~~~~~
mm/kasan/quarantine.c:239:16: note: in expansion of macro 'READ_ONCE'
total_size = (READ_ONCE(totalram_pages()) << PAGE_SHIFT) /
^~~~~~~~~
include/linux/compiler.h:248:28: error: lvalue required as unary '&' operand
__read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \
^
include/linux/compiler.h:252:22: note: in expansion of macro '__READ_ONCE'
#define READ_ONCE(x) __READ_ONCE(x, 1)
^~~~~~~~~~~
mm/kasan/quarantine.c:239:16: note: in expansion of macro 'READ_ONCE'
total_size = (READ_ONCE(totalram_pages()) << PAGE_SHIFT) /
^~~~~~~~~
--
include/linux/slab.h:332:43: warning: dubious: x & !y
include/linux/slab.h:332:43: warning: dubious: x & !y
>> net/sctp/protocol.c:1430:13: error: undefined identifier 'totalram_pgs'
net/sctp/protocol.c:1431:24: error: undefined identifier 'totalram_pgs'
net/sctp/protocol.c:1433:24: error: undefined identifier 'totalram_pgs'
>> /bin/bash: line 1: 74457 Segmentation fault sparse -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise -Wno-return-void -Wno-unknown-attribute -D__CHECK_ENDIAN__ -D__x86_64__ -mlittle-endian -m64 -Wp,-MD,net/sctp/.protocol.o.d -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/7/include -Iarch/x86/include -I./arch/x86/include/generated -Iinclude -I./include -Iarch/x86/include/uapi -I./arch/x86/include/generated/uapi -Iinclude/uapi -I./include/generated/uapi -include include/linux/kconfig.h -include include/linux/compiler_types.h -Inet/sctp -Inet/sctp -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -fshort-wchar -Werror-implicit-function-declaration -Wno-format-security -std=gnu89 -fno-PIE -DCC_HAVE_ASM_GOTO -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -m64 -falign-jumps=1 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mpreferred-stack-boundary=3 -mskip-rax-setup -mtune=generic -mno-red-zone -mcmodel=kernel -funit-at-a-time -DCONFIG_X86_X32_ABI -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -DCONFIG_AS_FXSAVEQ=1 -DCONFIG_AS_SSSE3=1 -DCONFIG_AS_AVX=1 -DCONFIG_AS_AVX2=1 -DCONFIG_AS_AVX512=1 -DCONFIG_AS_SHA1_NI=1 -DCONFIG_AS_SHA256_NI=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mindirect-branch=thunk-extern -mindirect-branch-register -DRETPOLINE -Wa,arch/x86/kernel/macros.s -Wa,- -fno-delete-null-pointer-checks -Wno-frame-address -Wno-format-truncation -Wno-format-overflow -Wno-int-in-bool-context -O2 --param=allow-store-data-races=0 -fplugin=./scripts/gcc-plugins/latent_entropy_plugin.so -fplugin=./scripts/gcc-plugins/structleak_plugin.so -fplugin=./scripts/gcc-plugins/randomize_layout_plugin.so -fplugin=./scripts/gcc-plugins/stackleak_plugin.so -DLATENT_ENTROPY_PLUGIN -DSTRUCTLEAK_PLUGIN -DRANDSTRUCT_PLUGIN -DSTACKLEAK_PLUGIN -fplugin-arg-stackleak_plugin-track-min-size=100 -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining -Wframe-larger-than=8192 -fstack-protector-strong -Wno-unused-but-set-variable -Wno-unused-const-variable -fno-var-tracking-assignments -pg -mrecord-mcount -mfentry -DCC_USING_FENTRY -fno-inline-functions-called-once -Wdeclaration-after-statement -Wvla -Wno-pointer-sign -fno-strict-overflow -fno-merge-all-constants -fmerge-constants -fno-stack-check -fconserve-stack -Werror=implicit-int -Werror=strict-prototypes -Werror=date-time -Werror=incompatible-pointer-types -Werror=designated-init -fsanitize=kernel-address -fasan-shadow-offset=0xdffffc0000000000 --param asan-globals=1 --param asan-instrumentation-with-call-threshold=0 --param asan-stack=1 -fsanitize-coverage=trace-pc -DMODULE -DKBUILD_BASENAME='"protocol"' -DKBUILD_MODNAME='"sctp"' net/sctp/protocol.c

vim +239 mm/kasan/quarantine.c

55834c59 Alexander Potapenko 2016-05-20 211
55834c59 Alexander Potapenko 2016-05-20 212 void quarantine_reduce(void)
55834c59 Alexander Potapenko 2016-05-20 213 {
64abdcb2 Dmitry Vyukov 2016-12-12 214 size_t total_size, new_quarantine_size, percpu_quarantines;
55834c59 Alexander Potapenko 2016-05-20 215 unsigned long flags;
ce5bec54 Dmitry Vyukov 2017-03-09 216 int srcu_idx;
55834c59 Alexander Potapenko 2016-05-20 217 struct qlist_head to_free = QLIST_INIT;
55834c59 Alexander Potapenko 2016-05-20 218
64abdcb2 Dmitry Vyukov 2016-12-12 219 if (likely(READ_ONCE(quarantine_size) <=
64abdcb2 Dmitry Vyukov 2016-12-12 220 READ_ONCE(quarantine_max_size)))
55834c59 Alexander Potapenko 2016-05-20 221 return;
55834c59 Alexander Potapenko 2016-05-20 222
ce5bec54 Dmitry Vyukov 2017-03-09 223 /*
ce5bec54 Dmitry Vyukov 2017-03-09 224 * srcu critical section ensures that quarantine_remove_cache()
ce5bec54 Dmitry Vyukov 2017-03-09 225 * will not miss objects belonging to the cache while they are in our
ce5bec54 Dmitry Vyukov 2017-03-09 226 * local to_free list. srcu is chosen because (1) it gives us private
ce5bec54 Dmitry Vyukov 2017-03-09 227 * grace period domain that does not interfere with anything else,
ce5bec54 Dmitry Vyukov 2017-03-09 228 * and (2) it allows synchronize_srcu() to return without waiting
ce5bec54 Dmitry Vyukov 2017-03-09 229 * if there are no pending read critical sections (which is the
ce5bec54 Dmitry Vyukov 2017-03-09 230 * expected case).
ce5bec54 Dmitry Vyukov 2017-03-09 231 */
ce5bec54 Dmitry Vyukov 2017-03-09 232 srcu_idx = srcu_read_lock(&remove_cache_srcu);
026d1eaf Clark Williams 2018-10-26 233 raw_spin_lock_irqsave(&quarantine_lock, flags);
55834c59 Alexander Potapenko 2016-05-20 234
55834c59 Alexander Potapenko 2016-05-20 235 /*
55834c59 Alexander Potapenko 2016-05-20 236 * Update quarantine size in case of hotplug. Allocate a fraction of
55834c59 Alexander Potapenko 2016-05-20 237 * the installed memory to quarantine minus per-cpu queue limits.
55834c59 Alexander Potapenko 2016-05-20 238 */
a399c534 Arun KS 2018-11-06 @239 total_size = (READ_ONCE(totalram_pages()) << PAGE_SHIFT) /
55834c59 Alexander Potapenko 2016-05-20 240 QUARANTINE_FRACTION;
c3cee372 Alexander Potapenko 2016-08-02 241 percpu_quarantines = QUARANTINE_PERCPU_SIZE * num_online_cpus();
64abdcb2 Dmitry Vyukov 2016-12-12 242 new_quarantine_size = (total_size < percpu_quarantines) ?
64abdcb2 Dmitry Vyukov 2016-12-12 243 0 : total_size - percpu_quarantines;
64abdcb2 Dmitry Vyukov 2016-12-12 244 WRITE_ONCE(quarantine_max_size, new_quarantine_size);
64abdcb2 Dmitry Vyukov 2016-12-12 245 /* Aim at consuming at most 1/2 of slots in quarantine. */
64abdcb2 Dmitry Vyukov 2016-12-12 246 WRITE_ONCE(quarantine_batch_size, max((size_t)QUARANTINE_PERCPU_SIZE,
64abdcb2 Dmitry Vyukov 2016-12-12 247 2 * total_size / QUARANTINE_BATCHES));
64abdcb2 Dmitry Vyukov 2016-12-12 248
64abdcb2 Dmitry Vyukov 2016-12-12 249 if (likely(quarantine_size > quarantine_max_size)) {
64abdcb2 Dmitry Vyukov 2016-12-12 250 qlist_move_all(&global_quarantine[quarantine_head], &to_free);
64abdcb2 Dmitry Vyukov 2016-12-12 251 WRITE_ONCE(quarantine_size, quarantine_size - to_free.bytes);
64abdcb2 Dmitry Vyukov 2016-12-12 252 quarantine_head++;
64abdcb2 Dmitry Vyukov 2016-12-12 253 if (quarantine_head == QUARANTINE_BATCHES)
64abdcb2 Dmitry Vyukov 2016-12-12 254 quarantine_head = 0;
55834c59 Alexander Potapenko 2016-05-20 255 }
55834c59 Alexander Potapenko 2016-05-20 256
026d1eaf Clark Williams 2018-10-26 257 raw_spin_unlock_irqrestore(&quarantine_lock, flags);
55834c59 Alexander Potapenko 2016-05-20 258
55834c59 Alexander Potapenko 2016-05-20 259 qlist_free_all(&to_free, NULL);
ce5bec54 Dmitry Vyukov 2017-03-09 260 srcu_read_unlock(&remove_cache_srcu, srcu_idx);
55834c59 Alexander Potapenko 2016-05-20 261 }
55834c59 Alexander Potapenko 2016-05-20 262

:::::: The code at line 239 was first introduced by commit
:::::: a399c534492723c9d2f175bc2b66aa930abd895f mm: convert totalram_pages and totalhigh_pages variables to atomic

:::::: TO: Arun KS <arunks@xxxxxxxxxxxxxx>
:::::: CC: 0day robot <lkp@xxxxxxxxx>

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Next message: Rich Felker: "Re: RFC: userspace exception fixups"
Previous message: Michael Ellerman: "Re: powerpc/npu-dma: Remove NPU DMA ops"
In reply to: Arun KS: "[PATCH v2 4/4] mm: Remove managed_page_count spinlock"
Next in thread: Arun KS: "[PATCH v2 2/4] mm: Convert zone->managed_pages to atomic variable"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]