On Sun, Feb 27, 2022 at 09:10:28PM -0800, Andrew Morton wrote: > > The patch titled > Subject: lib/stackdepot: use page allocator if both slab and memblock is unavailable > has been added to the -mm tree. Its filename is > lib-stackdepot-use-page-allocator-if-both-slab-and-memblock-is-unavailable.patch > > This patch should soon appear at > https://ozlabs.org/~akpm/mmots/broken-out/lib-stackdepot-use-page-allocator-if-both-slab-and-memblock-is-unavailable.patch > and later at > https://ozlabs.org/~akpm/mmotm/broken-out/lib-stackdepot-use-page-allocator-if-both-slab-and-memblock-is-unavailable.patch > > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's > > *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** > > The -mm tree is included into linux-next and is updated > there every 3-4 working days > Andrew, would you please drop this? I fixed this using another approach that Marco and Vlastimil suggested. https://lore.kernel.org/linux-mm/Yh2Uxh9DMndwjGcb@xxxxxxxxxxxxxxxxxxx-northeast-1.compute.internal/T/#u Thanks! > ------------------------------------------------------ > From: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> > Subject: lib/stackdepot: use page allocator if both slab and memblock is unavailable > > After commit 2dba5eb1c73b ("lib/stackdepot: allow optional init and > stack_table allocation by kvmalloc()"), stack_depot_init() is called later > if CONFIG_STACKDEPOT_ALWAYS_INIT=n to remove unnecessary memory usage. It > allocates stack_table using memblock_alloc() or kvmalloc() depending on > availability of slab allocator. > > But when stack_depot_init() is called while creating boot slab caches, > both slab allocator and memblock is not available. So kernel crashes. > Allocate stack_table from page allocator when both slab allocator and > memblock is unavailable. > > Limit size of stack_table when using page allocator because vmalloc() is > also unavailable in kmem_cache_init(). It must not be larger than > (PAGE_SIZE << (MAX_ORDER - 1)). > > This patch was tested on both CONFIG_STACKDEPOT_ALWAYS_INIT=y and n. > > [lkp@xxxxxxxxx: fix W=1 build warning] > Link: https://lkml.kernel.org/r/YhtDCoHWsF11rwze@xxxxxxxxxxxxxxxxxxx-northeast-1.compute.internal > Fixes: 2dba5eb1c73b ("lib/stackdepot: allow optional init and stack_table allocation by kvmalloc()") > Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> > Cc: Vlastimil Babka <vbabka@xxxxxxx> > Cc: David Rientjes <rientjes@xxxxxxxxxx> > Cc: Christoph Lameter <cl@xxxxxxxxx> > Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > Cc: Pekka Enberg <penberg@xxxxxxxxxx> > Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx> > Cc: Oliver Glitta <glittao@xxxxxxxxx> > Cc: Faiyaz Mohammed <faiyazm@xxxxxxxxxxxxxx> > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > Cc: Eric Dumazet <edumazet@xxxxxxxxxx> > Cc: Jarkko Sakkinen <jarkko@xxxxxxxxxx> > Cc: Johannes Berg <johannes.berg@xxxxxxxxx> > Cc: Yury Norov <yury.norov@xxxxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > Cc: Matteo Croce <mcroce@xxxxxxxxxxxxx> > Cc: Marco Elver <elver@xxxxxxxxxx> > Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx> > Cc: Imran Khan <imran.f.khan@xxxxxxxxxx> > Cc: Zqiang <qiang.zhang@xxxxxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > lib/stackdepot.c | 28 +++++++++++++++++++++------- > 1 file changed, 21 insertions(+), 7 deletions(-) > > --- a/lib/stackdepot.c~lib-stackdepot-use-page-allocator-if-both-slab-and-memblock-is-unavailable > +++ a/lib/stackdepot.c > @@ -73,6 +73,14 @@ static int next_slab_inited; > static size_t depot_offset; > static DEFINE_RAW_SPINLOCK(depot_lock); > > +static size_t stack_hash_size = (1 << CONFIG_STACK_HASH_ORDER); > +static inline size_t stack_hash_mask(void) > +{ > + return stack_hash_size - 1; > +} > + > +#define STACK_HASH_SEED 0x9747b28c > + > static bool init_stack_slab(void **prealloc) > { > if (!*prealloc) > @@ -142,10 +150,6 @@ depot_alloc_stack(unsigned long *entries > return stack; > } > > -#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER) > -#define STACK_HASH_MASK (STACK_HASH_SIZE - 1) > -#define STACK_HASH_SEED 0x9747b28c > - > static bool stack_depot_disable; > static struct stack_record **stack_table; > > @@ -172,18 +176,28 @@ __ref int stack_depot_init(void) > > mutex_lock(&stack_depot_init_mutex); > if (!stack_depot_disable && !stack_table) { > - size_t size = (STACK_HASH_SIZE * sizeof(struct stack_record *)); > + size_t size = (stack_hash_size * sizeof(struct stack_record *)); > int i; > > if (slab_is_available()) { > pr_info("Stack Depot allocating hash table with kvmalloc\n"); > stack_table = kvmalloc(size, GFP_KERNEL); > + } else if (totalram_pages() > 0) { > + /* Reduce size because vmalloc may be unavailable */ > + size = min_t(size_t, size, PAGE_SIZE << (MAX_ORDER - 1)); > + stack_hash_size = size / sizeof(struct stack_record *); > + > + pr_info("Stack Depot allocating hash table with __get_free_pages\n"); > + stack_table = (struct stack_record **) > + __get_free_pages(GFP_KERNEL, get_order(size)); > } else { > pr_info("Stack Depot allocating hash table with memblock_alloc\n"); > stack_table = memblock_alloc(size, SMP_CACHE_BYTES); > } > + > if (stack_table) { > - for (i = 0; i < STACK_HASH_SIZE; i++) > + pr_info("Stack Depot hash table size=%zu\n", stack_hash_size); > + for (i = 0; i < stack_hash_size; i++) > stack_table[i] = NULL; > } else { > pr_err("Stack Depot hash table allocation failed, disabling\n"); > @@ -363,7 +377,7 @@ depot_stack_handle_t __stack_depot_save( > goto fast_exit; > > hash = hash_stack(entries, nr_entries); > - bucket = &stack_table[hash & STACK_HASH_MASK]; > + bucket = &stack_table[hash & stack_hash_mask()]; > > /* > * Fast path: look the stack trace up without locking. > _ > > Patches currently in -mm which might be from 42.hyeyoo@xxxxxxxxx are > > lib-stackdepot-use-page-allocator-if-both-slab-and-memblock-is-unavailable.patch > -- Thank you, You are awesome! Hyeonggon :-)
