{"id":810200,"url":"http://patchwork.ozlabs.org/api/patches/810200/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/patch/20170905153123.13209-1-jakub.kicinski@netronome.com/","project":{"id":7,"url":"http://patchwork.ozlabs.org/api/projects/7/?format=json","name":"Linux network development","link_name":"netdev","list_id":"netdev.vger.kernel.org","list_email":"netdev@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170905153123.13209-1-jakub.kicinski@netronome.com>","list_archive_url":null,"date":"2017-09-05T15:31:23","name":"[net,v2] net: sched: don't use GFP_KERNEL under spin lock","commit_ref":null,"pull_url":null,"state":"accepted","archived":true,"hash":"996fb81ee2413f429947e1fa2254fff8d21d9748","submitter":{"id":67484,"url":"http://patchwork.ozlabs.org/api/people/67484/?format=json","name":"Jakub Kicinski","email":"jakub.kicinski@netronome.com"},"delegate":{"id":34,"url":"http://patchwork.ozlabs.org/api/users/34/?format=json","username":"davem","first_name":"David","last_name":"Miller","email":"davem@davemloft.net"},"mbox":"http://patchwork.ozlabs.org/project/netdev/patch/20170905153123.13209-1-jakub.kicinski@netronome.com/mbox/","series":[{"id":1598,"url":"http://patchwork.ozlabs.org/api/series/1598/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/list/?series=1598","date":"2017-09-05T15:31:23","name":"[net,v2] net: sched: don't use GFP_KERNEL under spin lock","version":2,"mbox":"http://patchwork.ozlabs.org/series/1598/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/810200/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/810200/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"patchwork-incoming@ozlabs.org","Delivered-To":"patchwork-incoming@ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; 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\n\tTue, 05 Sep 2017 08:31:52 -0700 (PDT)","From":"Jakub Kicinski ","To":"netdev@vger.kernel.org, eric.dumazet@gmail.com","Cc":"jiri@resnulli.us, Chris Mi ,\n\txiyou.wangcong@gmail.com, jhs@mojatatu.com, oss-drivers@netronome.com,\n\tJakub Kicinski ","Subject":"[PATCH net v2] net: sched: don't use GFP_KERNEL under spin lock","Date":"Tue, 5 Sep 2017 08:31:23 -0700","Message-Id":"<20170905153123.13209-1-jakub.kicinski@netronome.com>","X-Mailer":"git-send-email 2.14.1","Sender":"netdev-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"netdev@vger.kernel.org"},"content":"The new TC IDR code uses GFP_KERNEL under spin lock. Which leads\nto:\n\n[ 582.621091] BUG: sleeping function called from invalid context at ../mm/slab.h:416\n[ 582.629721] in_atomic(): 1, irqs_disabled(): 0, pid: 3379, name: tc\n[ 582.636939] 2 locks held by tc/3379:\n[ 582.641049] #0: (rtnl_mutex){+.+.+.}, at: [] rtnetlink_rcv_msg+0x92e/0x1400\n[ 582.650958] #1: (&(&tn->idrinfo->lock)->rlock){+.-.+.}, at: [] tcf_idr_create+0x2f0/0x8e0\n[ 582.662217] Preemption disabled at:\n[ 582.662222] [] tcf_idr_create+0x2f0/0x8e0\n[ 582.672592] CPU: 9 PID: 3379 Comm: tc Tainted: G W 4.13.0-rc7-debug-00648-g43503a79b9f0 #287\n[ 582.683432] Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.3.4 11/08/2016\n[ 582.691937] Call Trace:\n...\n[ 582.742460] kmem_cache_alloc+0x286/0x540\n[ 582.747055] radix_tree_node_alloc.constprop.6+0x4a/0x450\n[ 582.753209] idr_get_free_cmn+0x627/0xf80\n...\n[ 582.815525] idr_alloc_cmn+0x1a8/0x270\n...\n[ 582.833804] tcf_idr_create+0x31b/0x8e0\n...\n\nTry to preallocate the memory with idr_prealloc(GFP_KERNEL)\n(as suggested by Eric Dumazet), and change the allocation \nflags under spin lock.\n\nFixes: 65a206c01e8e (\"net/sched: Change act_api and act_xxx modules to use IDR\")\nSigned-off-by: Jakub Kicinski \nReviewed-by: Simon Horman \n---\n net/sched/act_api.c | 8 ++++++--\n 1 file changed, 6 insertions(+), 2 deletions(-)","diff":"diff --git a/net/sched/act_api.c b/net/sched/act_api.c\nindex 0eb545bcb247..a306974e2fb4 100644\n--- a/net/sched/act_api.c\n+++ b/net/sched/act_api.c\n@@ -296,10 +296,12 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,\n \tspin_lock_init(&p->tcfa_lock);\n \t/* user doesn't specify an index */\n \tif (!index) {\n+\t\tidr_preload(GFP_KERNEL);\n \t\tspin_lock_bh(&idrinfo->lock);\n \t\terr = idr_alloc_ext(idr, NULL, &idr_index, 1, 0,\n-\t\t\t\t GFP_KERNEL);\n+\t\t\t\t GFP_ATOMIC);\n \t\tspin_unlock_bh(&idrinfo->lock);\n+\t\tidr_preload_end();\n \t\tif (err) {\n err3:\n \t\t\tfree_percpu(p->cpu_qstats);\n@@ -307,10 +309,12 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,\n \t\t}\n \t\tp->tcfa_index = idr_index;\n \t} else {\n+\t\tidr_preload(GFP_KERNEL);\n \t\tspin_lock_bh(&idrinfo->lock);\n \t\terr = idr_alloc_ext(idr, NULL, NULL, index, index + 1,\n-\t\t\t\t GFP_KERNEL);\n+\t\t\t\t GFP_ATOMIC);\n \t\tspin_unlock_bh(&idrinfo->lock);\n+\t\tidr_preload_end();\n \t\tif (err)\n \t\t\tgoto err3;\n \t\tp->tcfa_index = index;\n","prefixes":["net","v2"]}