linux_dsm_epyc7002/lib
Daniel Mentz 62e931fac4 lib/genalloc.c: start search from start of chunk
gen_pool_alloc_algo() iterates over the chunks of a pool trying to find
a contiguous block of memory that satisfies the allocation request.

The shortcut

	if (size > atomic_read(&chunk->avail))
		continue;

makes the loop skip over chunks that do not have enough bytes left to
fulfill the request.  There are two situations, though, where an
allocation might still fail:

(1) The available memory is not contiguous, i.e.  the request cannot
    be fulfilled due to external fragmentation.

(2) A race condition.  Another thread runs the same code concurrently
    and is quicker to grab the available memory.

In those situations, the loop calls pool->algo() to search the entire
chunk, and pool->algo() returns some value that is >= end_bit to
indicate that the search failed.  This return value is then assigned to
start_bit.  The variables start_bit and end_bit describe the range that
should be searched, and this range should be reset for every chunk that
is searched.  Today, the code fails to reset start_bit to 0.  As a
result, prefixes of subsequent chunks are ignored.  Memory allocations
might fail even though there is plenty of room left in these prefixes of
those other chunks.

Fixes: 7f184275aa ("lib, Make gen_pool memory allocator lockless")
Link: http://lkml.kernel.org/r/1477420604-28918-1-git-send-email-danielmentz@google.com
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-27 18:43:43 -07:00
..
842
fonts
lz4
lzo
mpi lib/mpi: Fix SG miter leak 2016-07-29 18:30:16 +08:00
raid6 Merge tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2016-10-07 09:45:43 -07:00
reed_solomon
xz
zlib_deflate
zlib_inflate
.gitignore
argv_split.c
asn1_decoder.c
assoc_array.c
atomic64_test.c atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 2016-10-07 18:46:30 -07:00
atomic64.c locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() 2016-06-16 10:48:32 +02:00
audit.c
bcd.c
bch.c
bitmap.c lib/bitmap.c: enhance bitmap syntax 2016-10-11 15:06:30 -07:00
bitrev.c
bsearch.c
btree.c
bug.c
build_OID_registry
bust_spinlocks.c
chacha20.c random: replace non-blocking pool with a Chacha20-based CRNG 2016-07-03 00:57:23 -04:00
check_signature.c
checksum.c
clz_ctz.c
clz_tab.c
cmdline.c
compat_audit.c
cordic.c
cpu_rmap.c
cpu-notifier-error-inject.c fault-injection/cpu: Convert to hotplug state machine 2016-09-19 21:44:31 +02:00
cpumask.c
crc7.c
crc8.c
crc16.c
crc32.c crc32: use ktime_get_ns() for measurement 2016-08-02 19:35:08 -04:00
crc32defs.h
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c
debug_info.c
debug_locks.c
debugobjects.c debugobjects: insulate non-fixup logic related to static obj from fixup callbacks 2016-05-19 19:12:14 -07:00
dec_and_lock.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress.c
devres.c
digsig.c lib/digsig: digsig_verify_rsa(): return -EINVAL if modulo length is zero 2016-05-31 16:42:00 +08:00
div64.c
dma-debug.c dmaengine updates for 4.8-rc1 2016-10-06 17:13:54 -07:00
dma-noop.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
dump_stack.c
dynamic_debug.c dynamic_debug: add jump label support 2016-08-04 08:50:07 -04:00
dynamic_queue_limits.c
earlycpio.c lib/cpio: Make find_cpio_data()'s offset arg optional 2016-06-08 11:04:19 +02:00
extable.c
fault-inject.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit.c
flex_array.c
flex_proportions.c
gcd.c lib/GCD.c: use binary GCD algorithm instead of Euclidean 2016-05-20 17:58:30 -07:00
gen_crc32table.c
genalloc.c lib/genalloc.c: start search from start of chunk 2016-10-27 18:43:43 -07:00
glob.c
halfmd4.c
hexdump.c
hweight.c x86/hweight: Get rid of the special calling convention 2016-06-08 15:01:02 +02:00
idr.c
inflate.c
int_sqrt.c
interval_tree_test.c
interval_tree.c
iomap_copy.c
iomap.c
iommu-common.c
iommu-helper.c lib/iommu-helper: skip to next segment 2016-08-02 19:35:07 -04:00
ioremap.c
iov_iter.c iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector() 2016-10-14 20:00:34 -04:00
irq_poll.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
irq_regs.c
is_single_threaded.c
jedec_ddr_data.c
kasprintf.c
Kconfig Merge branch 'akpm' (patches from Andrew) 2016-10-07 21:38:00 -07:00
Kconfig.debug latent_entropy: raise CONFIG_FRAME_WARN by default 2016-10-27 18:43:43 -07:00
Kconfig.kasan mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB 2016-07-28 16:07:41 -07:00
Kconfig.kgdb kgdb: depends on VT 2016-05-23 17:04:14 -07:00
Kconfig.kmemcheck
Kconfig.ubsan ubsan: allow to disable the null sanitizer 2016-09-20 14:26:08 +02:00
kfifo.c
klist.c
kobject_uevent.c
kobject.c
kstrtox.c lib/kstrtox.c: smaller _parse_integer() 2016-10-11 15:06:30 -07:00
kstrtox.h
lcm.c
libcrc32c.c
list_debug.c
list_sort.c
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c
lockref.c
lru_cache.c
Makefile kcov: do not instrument lib/stackdepot.c 2016-10-11 15:06:32 -07:00
md5.c
memory-notifier-error-inject.c
memweight.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c
nmi_backtrace.c nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
nodemask.c include/linux/nodemask.h: create next_node_in() helper 2016-05-19 19:12:14 -07:00
notifier-error-inject.c
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
parser.c
pci_iomap.c
percpu_counter.c percpu_counter: update debugobjects fixup callbacks return type 2016-05-19 19:12:14 -07:00
percpu_ida.c
percpu_test.c
percpu-refcount.c percpu-refcount: init ->confirm_switch member properly 2016-08-11 13:52:23 -04:00
plist.c
pm-notifier-error-inject.c
radix-tree.c mm: filemap: don't plant shadow entries without radix tree node 2016-10-05 09:17:56 -07:00
random32.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
ratelimit.c ratelimit: extend to print suppressed messages on release 2016-08-02 19:35:06 -04:00
rational.c
rbtree_test.c
rbtree.c Introduce rb_replace_node_rcu() 2016-07-06 10:51:14 +01:00
reciprocal_div.c
rhashtable.c rhashtable: Add rhlist interface 2016-09-20 04:43:36 -04:00
sbitmap.c sbitmap: initialize weight to zero 2016-09-19 08:19:40 -06:00
scatterlist.c
seq_buf.c
sg_pool.c
sg_split.c
sha1.c
show_mem.c
smp_processor_id.c
sort.c
stackdepot.c lib/stackdepot.c: bump stackdepot capacity from 16MB to 128MB 2016-10-27 18:43:43 -07:00
stmp_device.c
string_helpers.c
string.c
strncpy_from_user.c lib: harden strncpy_from_user 2016-10-11 15:06:30 -07:00
strnlen_user.c unsafe_[get|put]_user: change interface to use a error target label 2016-08-08 13:02:01 -07:00
swiotlb.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
syscall.c lib/syscall: Pin the task stack in collect_syscall() 2016-09-16 09:18:53 +02:00
test_bitmap.c
test_bpf.c test_bpf: fix the dummy skb after dissector changes 2016-09-15 19:17:15 -04:00
test_firmware.c
test_hash.c lib/test_hash.c: fix warning in preprocessor symbol evaluation 2016-09-01 17:52:01 -07:00
test_hexdump.c
test_kasan.c kasan/tests: add tests for user memory access functions 2016-05-20 17:58:30 -07:00
test_module.c
test_printf.c
test_rhashtable.c rhashtable-test: Fix max_size parameter description 2016-08-08 12:52:42 -07:00
test_static_key_base.c
test_static_keys.c
test_user_copy.c
test_uuid.c lib/uuid: add a test module 2016-05-30 15:26:57 -07:00
test-kstrtox.c
test-string_helpers.c
textsearch.c
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c UBSAN: fix typo in format string 2016-08-02 17:31:41 -04:00
ubsan.h
ucs2_string.c lib/ucs2_string: Speed up ucs2_utf8size() 2016-09-09 16:08:46 +01:00
uuid.c lib/uuid.c: use correct offset in uuid parser 2016-05-30 15:26:57 -07:00
vsprintf.c lib/uuid.c: introduce a few more generic helpers 2016-05-20 17:58:30 -07:00
win_minmax.c lib/win_minmax: windowed min or max estimator 2016-09-21 00:22:59 -04:00