From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suren Baghdasaryan Subject: [PATCH 39/40] codetag: debug: introduce OBJEXTS_ALLOC_FAIL to mark failed slab_ext allocations Date: Mon, 1 May 2023 09:54:49 -0700 Message-ID: <20230501165450.15352-40-surenb@google.com> References: <20230501165450.15352-1-surenb@google.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1682960197; x=1685552197; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=6mzPQystPbLbDwPdw2fPo41K7qknlkieEKK3sweddW8=; b=48U8jHG63mdA66+jSc2MsTTE/SQi8BR+RKY6JNGvzt9XyZfx935vfOLln6IV1D1nZA TDOiQ/WUR049cZ5YJ1Q2SXSzODz7LrWrQUYaviS+GqGgkaK3yK5eLgyzf9e3cLjtYX0E QEA8ptoQ0G50fmCmay29a1/AGKziq1anSqyI04k35PIYMGlvV6wz4iKeKGJ75o0JVkmO ON7F5nilmKInR+kNfyJ2/HvMFyxBUo4zG20TTbLKq7fKcUY3NShJQ1fHpbVtH1cQdhj8 PGEM3ZzK108E7+nu3T246tg/tKyPHMfi0CFtYYsesaQA8cqlaVTRPDBW+c2GnGCMueBG 1wCA== In-Reply-To: <20230501165450.15352-1-surenb@google.com> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: akpm@linux-foundation.org Cc: kent.overstreet@linux.dev, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, roman.gushchin@linux.dev, mgorman@suse.de, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, corbet@lwn.net, void@manifault.com, peterz@infradead.org, juri.lelli@redhat.com, ldufour@linux.ibm.com, catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, peterx@redhat.com, david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org, nathan@kernel.org, dennis@kernel.org, tj@kernel.org, muchun.song@linux.dev, rppt@kernel.org, paulmck@kernel.org, pasha.tatashin@soleen.com, yosryahmed@google.com, yuzhao@google.com, dhowells@redhat.com, hughd@google.com, andreyknvl@gmail.com, keescook@chromium.org If slabobj_ext vector allocation for a slab object fails and later on it succeeds for another object in the same slab, the slabobj_ext for the original object will be NULL and will be flagged in case when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled. Mark failed slabobj_ext vector allocations using a new objext_flags flag stored in the lower bits of slab->obj_exts. When new allocation succeeds it marks all tag references in the same slabobj_ext vector as empty to avoid warnings implemented by CONFIG_MEM_ALLOC_PROFILING_DEBUG checks. Signed-off-by: Suren Baghdasaryan --- include/linux/memcontrol.h | 4 +++- mm/slab_common.c | 27 +++++++++++++++++++++++++-- 2 files changed, 28 insertions(+), 3 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index c7f21b15b540..3eb8975c1462 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -356,8 +356,10 @@ enum page_memcg_data_flags { #endif /* CONFIG_MEMCG */ enum objext_flags { + /* slabobj_ext vector failed to allocate */ + OBJEXTS_ALLOC_FAIL = __FIRST_OBJEXT_FLAG, /* the next bit after the last actual flag */ - __NR_OBJEXTS_FLAGS = __FIRST_OBJEXT_FLAG, + __NR_OBJEXTS_FLAGS = (__FIRST_OBJEXT_FLAG << 1), }; #define OBJEXTS_FLAGS_MASK (__NR_OBJEXTS_FLAGS - 1) diff --git a/mm/slab_common.c b/mm/slab_common.c index 89265f825c43..5b7e096b70a5 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -217,21 +217,44 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, { unsigned int objects = objs_per_slab(s, slab); unsigned long obj_exts; - void *vec; + struct slabobj_ext *vec; gfp &= ~OBJCGS_CLEAR_MASK; /* Prevent recursive extension vector allocation */ gfp |= __GFP_NO_OBJ_EXT; vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp, slab_nid(slab)); - if (!vec) + if (!vec) { +#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG + if (new_slab) { + /* Mark vectors which failed to allocate */ + slab->obj_exts = OBJEXTS_ALLOC_FAIL; +#ifdef CONFIG_MEMCG + slab->obj_exts |= MEMCG_DATA_OBJEXTS; +#endif + } +#endif return -ENOMEM; + } obj_exts = (unsigned long)vec; #ifdef CONFIG_MEMCG obj_exts |= MEMCG_DATA_OBJEXTS; #endif if (new_slab) { +#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG + /* + * If vector previously failed to allocate then we have live + * objects with no tag reference. Mark all references in this + * vector as empty to avoid warnings later on. + */ + if (slab->obj_exts & OBJEXTS_ALLOC_FAIL) { + unsigned int i; + + for (i = 0; i < objects; i++) + set_codetag_empty(&vec[i].ref); + } +#endif /* * If the slab is brand new and nobody can yet access its * obj_exts, no synchronization is required and obj_exts can -- 2.40.1.495.gc816e09b53d-goog