From mboxrd@z Thu Jan 1 00:00:00 1970 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=-0.5 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 D2ABFC3A5A2 for ; Sat, 24 Aug 2019 02:57:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 66C1921726 for ; Sat, 24 Aug 2019 02:57:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 66C1921726 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id ECEB16B04D0; Fri, 23 Aug 2019 22:57:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E56BC6B04D1; Fri, 23 Aug 2019 22:57:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D1E586B04D2; Fri, 23 Aug 2019 22:57:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0126.hostedemail.com [216.40.44.126]) by kanga.kvack.org (Postfix) with ESMTP id A92166B04D0 for ; Fri, 23 Aug 2019 22:57:44 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 344826418 for ; Sat, 24 Aug 2019 02:57:44 +0000 (UTC) X-FDA: 75855811248.22.trip99_4358ff75d2832 X-HE-Tag: trip99_4358ff75d2832 X-Filterd-Recvd-Size: 7305 Received: from r3-21.sinamail.sina.com.cn (r3-21.sinamail.sina.com.cn [202.108.3.21]) by imf38.hostedemail.com (Postfix) with SMTP for ; Sat, 24 Aug 2019 02:57:42 +0000 (UTC) Received: from unknown (HELO localhost.localdomain)([124.64.0.77]) by sina.com with ESMTP id 5D60A7A200023491; Sat, 24 Aug 2019 10:57:40 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com X-SMAIL-MID: 142829752972 From: Hillf Danton To: Adric Blake Cc: akpm@linux-foundation.org, ktkhai@virtuozzo.com, hannes@cmpxchg.org, mhocko@suse.com, daniel.m.jordan@oracle.com, laoar.shao@gmail.com, yang.shi@linux.alibaba.com, mgorman@techsingularity.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: WARNINGs in set_task_reclaim_state with memory cgroup and full memory usage Date: Sat, 24 Aug 2019 10:57:26 +0800 Message-Id: <20190824025726.14032-1-hdanton@sina.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: On Fri, 23 Aug 2019 18:00:15 -0400 Adric Blake wrote: > Synopsis: > A WARN_ON_ONCE is hit twice in set_task_reclaim_state under the > following conditions: > - a memory cgroup has been created and a task assigned it it > - memory.limit_in_bytes has been set > - memory has filled up, likely from cache >=20 Thanks for report. > In my usage, I create a cgroup under the current session scope and > assign a task to it. I then set memory.limit_in_bytes and > memory.soft_limit_in_bytes for the cgroup to reasonable values, say > 1G/512M. The program accesses large files frequently and gradually > fills memory with the page cache. The warnings appears when the > entirety of the system memory is filled, presumably from other > programs. >=20 > If I wait until the program has filled the entirety of system memory > with cache and then assign a memory limit, the warnings appear > immediately. >=20 > I am building the linux git. I first noticed this issue with the > drm-tip 5.3rc3 and 5.3rc4 kernels, and tested linux master after > 5.3rc5 to confirm the bug more resoundingly. >=20 > Here are the warnings. >=20 > [38491.963105] WARNING: CPU: 7 PID: 175 at mm/vmscan.c:245 set_task_rec= laim_state+0x1e/0x40 > [38491.963106] Modules linked in: iwlmvm mac80211 libarc4 iwlwifi > cfg80211 xt_comment nls_iso8859_1 nls_cp437 vfat fat xfs jfs btrfs xor > raid6_pq libcrc32c ccm tun rfcomm fuse xt_tcpudp ip6t_REJECT > nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_multiport xt_owner > snd_hda_codec_hdmi ip6table_filter ip6_tables iptable_filter bnep ext4 > crc32c_generic mbcache jbd2 snd_hda_codec_realtek > snd_hda_codec_generic snd_soc_skl snd_soc_hdac_hda snd_hda_ext_core > snd_soc_skl_ipc x86_pkg_temp_thermal intel_powerclamp snd_soc_sst_ipc > coretemp snd_soc_sst_dsp snd_soc_acpi_intel_match kvm_intel > snd_soc_acpi i915 snd_soc_core kvm snd_compress ac97_bus > snd_pcm_dmaengine snd_hda_intel i2c_algo_bit btusb irqbypass > drm_kms_helper btrtl snd_hda_codec dell_laptop btbcm crct10dif_pclmul > snd_hda_core crc32c_intel btintel iTCO_wdt ghash_clmulni_intel drm > ledtrig_audio aesni_intel iTCO_vendor_support snd_hwdep dell_wmi > rtsx_usb_ms r8169 dell_smbios aes_x86_64 mei_hdcp crypto_simd > intel_gtt bluetooth snd_pcm cryptd dcdbas > [38491.963155] wmi_bmof dell_wmi_descriptor intel_rapl_msr > glue_helper snd_timer joydev intel_cstate snd realtek memstick > dell_smm_hwmon mousedev psmouse input_leds libphy intel_uncore > ecdh_generic ecc crc16 rfkill intel_rapl_perf soundcore i2c_i801 > agpgart mei_me tpm_crb syscopyarea sysfillrect sysimgblt mei > intel_xhci_usb_role_switch fb_sys_fops idma64 tpm_tis roles > processor_thermal_device intel_rapl_common i2c_hid tpm_tis_core > int3403_thermal intel_soc_dts_iosf battery wmi intel_lpss_pci > intel_lpss intel_pch_thermal tpm int3400_thermal int3402_thermal > acpi_thermal_rel int340x_thermal_zone rng_core intel_hid ac > sparse_keymap evdev mac_hid crypto_user ip_tables x_tables > hid_multitouch rtsx_usb_sdmmc mmc_core rtsx_usb hid_logitech_hidpp > sr_mod cdrom sd_mod uas usb_storage hid_logitech_dj hid_generic usbhid > hid ahci serio_raw libahci atkbd libps2 libata xhci_pci scsi_mod > xhci_hcd crc32_pclmul i8042 serio f2fs [last unloaded: cfg80211] > [38491.963221] CPU: 7 PID: 175 Comm: kswapd0 Not tainted 5.3.0-rc5+149+= gbb7ba8069de9 #1 > [38491.963222] Hardware name: Dell Inc. Inspiron 5570/09YTN7, BIOS 1.2.= 3 05/15/2019 > [38491.963226] RIP: 0010:set_task_reclaim_state+0x1e/0x40 > [38491.963228] Code: 78 a9 e7 ff 0f 1f 84 00 00 00 00 00 0f 1f 44 00 > 00 55 48 89 f5 53 48 89 fb 48 85 ed 48 8b 83 08 08 00 00 74 11 48 85 > c0 74 02 <0f> 0b 48 89 ab 08 08 00 00 5b 5d c3 48 85 c0 75 f1 0f 0b 48 > 89 ab > [38491.963229] RSP: 0018:ffff8c898031fc60 EFLAGS: 00010286 > [38491.963230] RAX: ffff8c898031fe28 RBX: ffff892aa04ddc40 RCX: 0000000= 000000000 > [38491.963231] RDX: ffff8c898031fc60 RSI: ffff8c898031fcd0 RDI: ffff892= aa04ddc40 > [38491.963233] RBP: ffff8c898031fcd0 R08: ffff8c898031fd48 R09: ffff892= 79674b800 > [38491.963234] R10: 00000000ffffffff R11: 0000000000000000 R12: ffff8c8= 98031fd48 > [38491.963235] R13: ffff892a842ef000 R14: ffff892aaf7fc000 R15: 0000000= 000000000 > [38491.963236] FS: 0000000000000000(0000) GS:ffff892aa33c0000(0000) kn= lGS:0000000000000000 > [38491.963238] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [38491.963239] CR2: 00007f90628fa000 CR3: 000000027ee0a002 CR4: 0000000= 0003606e0 > [38491.963239] Call Trace: > [38491.963246] mem_cgroup_shrink_node+0x9b/0x1d0 > [38491.963250] mem_cgroup_soft_limit_reclaim+0x10c/0x3a0 > [38491.963254] balance_pgdat+0x276/0x540 > [38491.963258] kswapd+0x200/0x3f0 > [38491.963261] ? wait_woken+0x80/0x80 > [38491.963265] kthread+0xfd/0x130 > [38491.963267] ? balance_pgdat+0x540/0x540 > [38491.963269] ? kthread_park+0x80/0x80 > [38491.963273] ret_from_fork+0x35/0x40 > [38491.963276] ---[ end trace 727343df67b2398a ]--- Save and restore reclaim state for global reclaimer as it can be clobbered by memcg. --- a/mm/vmscan.c +++ b/bb/vmscan.c @@ -253,6 +253,22 @@ static void set_task_reclaim_state(struc task->reclaim_state =3D rs; } =20 +static struct reclaim_state * +save_task_reclaim_state(struct task_struct *task) +{ + struct reclaim_state *rs =3D task->reclaim_state; + if (rs) + set_task_reclaim_state(task, NULL); + return rs; +} + +static void restore_task_reclaim_state(struct task_struct *task, + struct reclaim_state *rs) +{ + if (rs) + set_task_reclaim_state(task, rs); +} + #ifdef CONFIG_MEMCG static bool global_reclaim(struct scan_control *sc) { @@ -3241,7 +3257,9 @@ unsigned long mem_cgroup_shrink_node(str .may_shrinkslab =3D 1, }; unsigned long lru_pages; + struct reclaim_state *rs; =20 + rs =3D save_task_reclaim_state(current); set_task_reclaim_state(current, &sc.reclaim_state); sc.gfp_mask =3D (gfp_mask & GFP_RECLAIM_MASK) | (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK); @@ -3261,6 +3279,7 @@ unsigned long mem_cgroup_shrink_node(str trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed); =20 set_task_reclaim_state(current, NULL); + restore_task_reclaim_state(current, rs); *nr_scanned =3D sc.nr_scanned; =20 return sc.nr_reclaimed; --