From patchwork Wed May 5 15:46:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 12240271 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1357EC433B4 for ; Wed, 5 May 2021 15:47:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9D72561157 for ; Wed, 5 May 2021 15:47:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D72561157 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 32DFC6B0071; Wed, 5 May 2021 11:47:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2DD5E6B0072; Wed, 5 May 2021 11:47:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 12FBD6B0073; Wed, 5 May 2021 11:47:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0195.hostedemail.com [216.40.44.195]) by kanga.kvack.org (Postfix) with ESMTP id EA4256B0071 for ; Wed, 5 May 2021 11:47:39 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 1F0B7180AD81F for ; Wed, 5 May 2021 15:47:39 +0000 (UTC) X-FDA: 78107607438.27.3735FCB Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf23.hostedemail.com (Postfix) with ESMTP id 3861CA0003A2 for ; Wed, 5 May 2021 15:47:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620229658; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=UYxtPKpE548sgyGm/1fmGwS+oSULE1eFSrQRq98f+o4=; b=YGnUd7+spKG43oVAR2uVEvdOx/5T6yhy+bjSdjFjVvuhnaDSXV5dlgZO3l415azTNWBGo9 +OOBL6iUiBTmK8QiEYmwyUWaprshZ/4H1a8fdYad8+dN8XTSlDPTIBa95yVf8T5C3Kwbq+ Nz1gmKXqaU9Xivcs74ZHftIO+JgK9kc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-137-fQrnHrtDOCynD-6wzndQNw-1; Wed, 05 May 2021 11:47:27 -0400 X-MC-Unique: fQrnHrtDOCynD-6wzndQNw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DF23F835DE0; Wed, 5 May 2021 15:47:24 +0000 (UTC) Received: from llong.com (ovpn-117-4.rdu2.redhat.com [10.10.117.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 387995D6AC; Wed, 5 May 2021 15:47:22 +0000 (UTC) From: Waiman Long To: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin , Shakeel Butt Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Waiman Long Subject: [PATCH v3 1/2] mm: memcg/slab: Properly set up gfp flags for objcg pointer array Date: Wed, 5 May 2021 11:46:12 -0400 Message-Id: <20210505154613.17214-2-longman@redhat.com> In-Reply-To: <20210505154613.17214-1-longman@redhat.com> References: <20210505154613.17214-1-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=YGnUd7+s; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf23.hostedemail.com: domain of longman@redhat.com has no SPF policy when checking 216.205.24.124) smtp.mailfrom=longman@redhat.com X-Rspamd-Server: rspam03 X-Stat-Signature: hwzcgtsx345q1asarjf4ax6rqmk1ir3k X-Rspamd-Queue-Id: 3861CA0003A2 Received-SPF: none (redhat.com>: No applicable sender policy available) receiver=imf23; identity=mailfrom; envelope-from=""; helo=us-smtp-delivery-124.mimecast.com; client-ip=216.205.24.124 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1620229651-554304 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Since the merging of the new slab memory controller in v5.9, the page structure may store a pointer to obj_cgroup pointer array for slab pages. Currently, only the __GFP_ACCOUNT bit is masked off. However, the array is not readily reclaimable and doesn't need to come from the DMA buffer. So those GFP bits should be masked off as well. Do the flag bit clearing at memcg_alloc_page_obj_cgroups() to make sure that it is consistently applied no matter where it is called. Fixes: 286e04b8ed7a ("mm: memcg/slab: allocate obj_cgroups for non-root slab pages") Signed-off-by: Waiman Long Reviewed-by: Shakeel Butt Acked-by: Roman Gushchin --- mm/memcontrol.c | 8 ++++++++ mm/slab.h | 1 - 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c100265dc393..5e3b4f23b830 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2863,6 +2863,13 @@ static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg) } #ifdef CONFIG_MEMCG_KMEM +/* + * The allocated objcg pointers array is not accounted directly. + * Moreover, it should not come from DMA buffer and is not readily + * reclaimable. So those GFP bits should be masked off. + */ +#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) + int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, gfp_t gfp, bool new_page) { @@ -2870,6 +2877,7 @@ int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, unsigned long memcg_data; void *vec; + gfp &= ~OBJCGS_CLEAR_MASK; vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, page_to_nid(page)); if (!vec) diff --git a/mm/slab.h b/mm/slab.h index 18c1927cd196..b3294712a686 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -309,7 +309,6 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, if (!memcg_kmem_enabled() || !objcg) return; - flags &= ~__GFP_ACCOUNT; for (i = 0; i < size; i++) { if (likely(p[i])) { page = virt_to_head_page(p[i]); From patchwork Wed May 5 15:46:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 12240269 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88E69C43460 for ; Wed, 5 May 2021 15:47:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1377D613BF for ; Wed, 5 May 2021 15:47:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1377D613BF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 96F626B0070; Wed, 5 May 2021 11:47:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 91F3B6B0071; Wed, 5 May 2021 11:47:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 74B6B6B0072; Wed, 5 May 2021 11:47:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0229.hostedemail.com [216.40.44.229]) by kanga.kvack.org (Postfix) with ESMTP id 58B9D6B0070 for ; Wed, 5 May 2021 11:47:35 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 1696282499A8 for ; Wed, 5 May 2021 15:47:35 +0000 (UTC) X-FDA: 78107607270.24.A6B33B7 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf06.hostedemail.com (Postfix) with ESMTP id 35E1CC0007E6 for ; Wed, 5 May 2021 15:47:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620229654; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=FV79wzI0ybKmDD4PCzgFiPvPREI8TgBBCI9BsjVwJeA=; b=QoIaLUYgMlbBRHFjemPqIpmE4snF8i4nTXvZJ6yFwqY38qtmh9h2vDX/Hj5TZ6AOlwwbKA vB56VYnBpFWdW9BiLPefFqyBVdKIXWPW/i1AiKvwUpNEHx8E6/oY++zFX5nwvimepfWaLX A3wor9MIvlztsY9oKszBTOaQ7kH954M= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-27-93TtN9YIMPyJlUmUItQirw-1; Wed, 05 May 2021 11:47:30 -0400 X-MC-Unique: 93TtN9YIMPyJlUmUItQirw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 039E5835DE3; Wed, 5 May 2021 15:47:27 +0000 (UTC) Received: from llong.com (ovpn-117-4.rdu2.redhat.com [10.10.117.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 17C345D6AC; Wed, 5 May 2021 15:47:25 +0000 (UTC) From: Waiman Long To: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin , Shakeel Butt Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Waiman Long Subject: [PATCH v3 2/2] mm: memcg/slab: Create a new set of kmalloc-cg- caches Date: Wed, 5 May 2021 11:46:13 -0400 Message-Id: <20210505154613.17214-3-longman@redhat.com> In-Reply-To: <20210505154613.17214-1-longman@redhat.com> References: <20210505154613.17214-1-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=QoIaLUYg; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf06.hostedemail.com: domain of longman@redhat.com has no SPF policy when checking 216.205.24.124) smtp.mailfrom=longman@redhat.com X-Rspamd-Server: rspam03 X-Stat-Signature: h4eo36qttnqqw6bcogewuw5nx6ymzbu3 X-Rspamd-Queue-Id: 35E1CC0007E6 Received-SPF: none (redhat.com>: No applicable sender policy available) receiver=imf06; identity=mailfrom; envelope-from=""; helo=us-smtp-delivery-124.mimecast.com; client-ip=216.205.24.124 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1620229656-914905 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: There are currently two problems in the way the objcg pointer array (memcg_data) in the page structure is being allocated and freed. On its allocation, it is possible that the allocated objcg pointer array comes from the same slab that requires memory accounting. If this happens, the slab will never become empty again as there is at least one object left (the obj_cgroup array) in the slab. When it is freed, the objcg pointer array object may be the last one in its slab and hence causes kfree() to be called again. With the right workload, the slab cache may be set up in a way that allows the recursive kfree() calling loop to nest deep enough to cause a kernel stack overflow and panic the system. One way to solve this problem is to split the kmalloc- caches (KMALLOC_NORMAL) into two separate sets - a new set of kmalloc- (KMALLOC_NORMAL) caches for non-accounted objects only and a new set of kmalloc-cg- (KMALLOC_CGROUP) caches for accounted objects only. All the other caches can still allow a mix of accounted and non-accounted objects. With this change, all the objcg pointer array objects will come from KMALLOC_NORMAL caches which won't have their objcg pointer arrays. So both the recursive kfree() problem and non-freeable slab problem are gone. Since both the KMALLOC_NORMAL and KMALLOC_CGROUP caches no longer have mixed accounted and unaccounted objects, this will slightly reduce the number of objcg pointer arrays that need to be allocated and save a bit of memory. The new KMALLOC_CGROUP is added between KMALLOC_NORMAL and KMALLOC_RECLAIM so that the first for loop in create_kmalloc_caches() will include the newly added caches without change. Suggested-by: Vlastimil Babka Signed-off-by: Waiman Long Reviewed-by: Shakeel Butt --- include/linux/slab.h | 42 ++++++++++++++++++++++++++++++++++-------- mm/slab_common.c | 23 +++++++++++++++-------- 2 files changed, 49 insertions(+), 16 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index 0c97d788762c..f2d9ebc34f5c 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -305,9 +305,16 @@ static inline void __check_heap_object(const void *ptr, unsigned long n, /* * Whenever changing this, take care of that kmalloc_type() and * create_kmalloc_caches() still work as intended. + * + * KMALLOC_NORMAL is for non-accounted objects only whereas KMALLOC_CGROUP + * is for accounted objects only. All the other kmem caches can have both + * accounted and non-accounted objects. */ enum kmalloc_cache_type { KMALLOC_NORMAL = 0, +#ifdef CONFIG_MEMCG_KMEM + KMALLOC_CGROUP, +#endif KMALLOC_RECLAIM, #ifdef CONFIG_ZONE_DMA KMALLOC_DMA, @@ -315,28 +322,47 @@ enum kmalloc_cache_type { NR_KMALLOC_TYPES }; +#ifndef CONFIG_MEMCG_KMEM +#define KMALLOC_CGROUP KMALLOC_NORMAL +#endif +#ifndef CONFIG_ZONE_DMA +#define KMALLOC_DMA KMALLOC_NORMAL +#endif + #ifndef CONFIG_SLOB extern struct kmem_cache * kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; +/* + * Define gfp bits that should not be set for KMALLOC_NORMAL. + */ +#define KMALLOC_NOT_NORMAL_BITS \ + (__GFP_RECLAIMABLE | \ + (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ + (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) + static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) { -#ifdef CONFIG_ZONE_DMA /* * The most common case is KMALLOC_NORMAL, so test for it * with a single branch for both flags. */ - if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0)) + if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) return KMALLOC_NORMAL; /* - * At least one of the flags has to be set. If both are, __GFP_DMA - * is more important. + * At least one of the flags has to be set. Their priorities in + * decreasing order are: + * 1) __GFP_DMA + * 2) __GFP_RECLAIMABLE + * 3) __GFP_ACCOUNT */ - return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM; -#else - return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL; -#endif + if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) + return KMALLOC_DMA; + if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) + return KMALLOC_RECLAIM; + else + return KMALLOC_CGROUP; } /* diff --git a/mm/slab_common.c b/mm/slab_common.c index f8833d3e5d47..d750e3ba7af5 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -727,21 +727,25 @@ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) } #ifdef CONFIG_ZONE_DMA -#define INIT_KMALLOC_INFO(__size, __short_size) \ -{ \ - .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \ - .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \ - .name[KMALLOC_DMA] = "dma-kmalloc-" #__short_size, \ - .size = __size, \ -} +#define KMALLOC_DMA_NAME(sz) .name[KMALLOC_DMA] = "dma-kmalloc-" #sz, +#else +#define KMALLOC_DMA_NAME(sz) +#endif + +#ifdef CONFIG_MEMCG_KMEM +#define KMALLOC_CGROUP_NAME(sz) .name[KMALLOC_CGROUP] = "kmalloc-cg-" #sz, #else +#define KMALLOC_CGROUP_NAME(sz) +#endif + #define INIT_KMALLOC_INFO(__size, __short_size) \ { \ .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \ .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \ + KMALLOC_CGROUP_NAME(__short_size) \ + KMALLOC_DMA_NAME(__short_size) \ .size = __size, \ } -#endif /* * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time. @@ -847,6 +851,9 @@ void __init create_kmalloc_caches(slab_flags_t flags) int i; enum kmalloc_cache_type type; + /* + * Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined + */ for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) { for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { if (!kmalloc_caches[type][i])