Commit-ID: af52bf6b92f7d8783c1e712cad6ef7d37cd773b2 Gitweb: https://git.kernel.org/tip/af52bf6b92f7d8783c1e712cad6ef7d37cd773b2 Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Thu, 25 Apr 2019 11:45:03 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Mon, 29 Apr 2019 12:37:50 +0200
mm/page_owner: Simplify stack trace handling Replace the indirection through struct stack_trace by using the storage array based interfaces. The original code in all printing functions is really wrong. It allocates a storage array on stack which is unused because depot_fetch_stack() does not store anything in it. It overwrites the entries pointer in the stack_trace struct so it points to the depot storage. Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: linux...@kvack.org Cc: Mike Rapoport <r...@linux.vnet.ibm.com> Cc: David Rientjes <rient...@google.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Alexander Potapenko <gli...@google.com> Cc: Alexey Dobriyan <adobri...@gmail.com> Cc: Christoph Lameter <c...@linux.com> Cc: Pekka Enberg <penb...@kernel.org> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Dmitry Vyukov <dvyu...@google.com> Cc: Andrey Ryabinin <aryabi...@virtuozzo.com> Cc: kasan-...@googlegroups.com Cc: Akinobu Mita <akinobu.m...@gmail.com> Cc: Christoph Hellwig <h...@lst.de> Cc: io...@lists.linux-foundation.org Cc: Robin Murphy <robin.mur...@arm.com> Cc: Marek Szyprowski <m.szyprow...@samsung.com> Cc: Johannes Thumshirn <jthumsh...@suse.de> Cc: David Sterba <dste...@suse.com> Cc: Chris Mason <c...@fb.com> Cc: Josef Bacik <jo...@toxicpanda.com> Cc: linux-bt...@vger.kernel.org Cc: dm-de...@redhat.com Cc: Mike Snitzer <snit...@redhat.com> Cc: Alasdair Kergon <a...@redhat.com> Cc: Daniel Vetter <dan...@ffwll.ch> Cc: intel-...@lists.freedesktop.org Cc: Joonas Lahtinen <joonas.lahti...@linux.intel.com> Cc: Maarten Lankhorst <maarten.lankho...@linux.intel.com> Cc: dri-de...@lists.freedesktop.org Cc: David Airlie <airl...@linux.ie> Cc: Jani Nikula <jani.nik...@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.v...@intel.com> Cc: Tom Zanussi <tom.zanu...@linux.intel.com> Cc: Miroslav Benes <mbe...@suse.cz> Cc: linux-a...@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.067210...@linutronix.de --- mm/page_owner.c | 79 ++++++++++++++++++++------------------------------------- 1 file changed, 28 insertions(+), 51 deletions(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index df277e6bc3c6..addcbb2ae4e4 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -58,15 +58,10 @@ static bool need_page_owner(void) static __always_inline depot_stack_handle_t create_dummy_stack(void) { unsigned long entries[4]; - struct stack_trace dummy; + unsigned int nr_entries; - dummy.nr_entries = 0; - dummy.max_entries = ARRAY_SIZE(entries); - dummy.entries = &entries[0]; - dummy.skip = 0; - - save_stack_trace(&dummy); - return depot_save_stack(&dummy, GFP_KERNEL); + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); + return stack_depot_save(entries, nr_entries, GFP_KERNEL); } static noinline void register_dummy_stack(void) @@ -120,46 +115,39 @@ void __reset_page_owner(struct page *page, unsigned int order) } } -static inline bool check_recursive_alloc(struct stack_trace *trace, - unsigned long ip) +static inline bool check_recursive_alloc(unsigned long *entries, + unsigned int nr_entries, + unsigned long ip) { - int i; - - if (!trace->nr_entries) - return false; + unsigned int i; - for (i = 0; i < trace->nr_entries; i++) { - if (trace->entries[i] == ip) + for (i = 0; i < nr_entries; i++) { + if (entries[i] == ip) return true; } - return false; } static noinline depot_stack_handle_t save_stack(gfp_t flags) { unsigned long entries[PAGE_OWNER_STACK_DEPTH]; - struct stack_trace trace = { - .nr_entries = 0, - .entries = entries, - .max_entries = PAGE_OWNER_STACK_DEPTH, - .skip = 2 - }; depot_stack_handle_t handle; + unsigned int nr_entries; - save_stack_trace(&trace); + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); /* - * We need to check recursion here because our request to stackdepot - * could trigger memory allocation to save new entry. New memory - * allocation would reach here and call depot_save_stack() again - * if we don't catch it. There is still not enough memory in stackdepot - * so it would try to allocate memory again and loop forever. + * We need to check recursion here because our request to + * stackdepot could trigger memory allocation to save new + * entry. New memory allocation would reach here and call + * stack_depot_save_entries() again if we don't catch it. There is + * still not enough memory in stackdepot so it would try to + * allocate memory again and loop forever. */ - if (check_recursive_alloc(&trace, _RET_IP_)) + if (check_recursive_alloc(entries, nr_entries, _RET_IP_)) return dummy_handle; - handle = depot_save_stack(&trace, flags); + handle = stack_depot_save(entries, nr_entries, flags); if (!handle) handle = failure_handle; @@ -337,16 +325,10 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, struct page *page, struct page_owner *page_owner, depot_stack_handle_t handle) { - int ret; - int pageblock_mt, page_mt; + int ret, pageblock_mt, page_mt; + unsigned long *entries; + unsigned int nr_entries; char *kbuf; - unsigned long entries[PAGE_OWNER_STACK_DEPTH]; - struct stack_trace trace = { - .nr_entries = 0, - .entries = entries, - .max_entries = PAGE_OWNER_STACK_DEPTH, - .skip = 0 - }; count = min_t(size_t, count, PAGE_SIZE); kbuf = kmalloc(count, GFP_KERNEL); @@ -375,8 +357,8 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, if (ret >= count) goto err; - depot_fetch_stack(handle, &trace); - ret += snprint_stack_trace(kbuf + ret, count - ret, &trace, 0); + nr_entries = stack_depot_fetch(handle, &entries); + ret += stack_trace_snprint(kbuf + ret, count - ret, entries, nr_entries, 0); if (ret >= count) goto err; @@ -407,14 +389,9 @@ void __dump_page_owner(struct page *page) { struct page_ext *page_ext = lookup_page_ext(page); struct page_owner *page_owner; - unsigned long entries[PAGE_OWNER_STACK_DEPTH]; - struct stack_trace trace = { - .nr_entries = 0, - .entries = entries, - .max_entries = PAGE_OWNER_STACK_DEPTH, - .skip = 0 - }; depot_stack_handle_t handle; + unsigned long *entries; + unsigned int nr_entries; gfp_t gfp_mask; int mt; @@ -438,10 +415,10 @@ void __dump_page_owner(struct page *page) return; } - depot_fetch_stack(handle, &trace); + nr_entries = stack_depot_fetch(handle, &entries); pr_alert("page allocated via order %u, migratetype %s, gfp_mask %#x(%pGg)\n", page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask); - print_stack_trace(&trace, 0); + stack_trace_print(entries, nr_entries, 0); if (page_owner->last_migrate_reason != -1) pr_alert("page has been migrated, last migrate reason: %s\n",
