On Thu, Jun 28, 2018 at 02:03:47PM +0800, jianchao.wang wrote: > > > On 06/28/2018 01:42 PM, Kashyap Desai wrote: > > Ming - > > > > Performance drop is resolved on my setup, but may be some stability of the > > kernel is caused due to this patch set. I have not tried without patch > > set, but in case you can figure out if below crash is due to this patch > > set, I can try potential fix as well. I am seeing kernel panic if I use > > below three settings in my fio script. > > > > iodepth_batch=8 > > iodepth_batch_complete_min=4 > > iodepth_batch_complete_max=16 > > > > > > Here is panic detail - > > > > [65237.831029] ------------[ cut here ]------------ > > [65237.831031] list_add corruption. prev->next should be next > > (ffffbb1d0a41fdf8), but was ffff94d0f0c57240. (prev=ffff94d0f0c57240). > > [65237.831046] WARNING: CPU: 18 PID: 13897 at lib/list_debug.c:28 > > __list_add_valid+0x6a/0x70 > > [65237.831046] Modules linked in: mpt3sas raid_class ses enclosure > > scsi_transport_sas megaraid_sas(OE) xt_CHECKSUM ipt_MASQUERADE tun > > ip6t_rpfilter ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 > > xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc > > ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle > > ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 > > nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle > > iptable_security iptable_raw ebtable_filter ebtables ip6table_filter > > ip6_tables iptable_filter intel_rapl skx_edac nfit libnvdimm > > x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass > > crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel > > snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel crypto_simd > > cryptd > > [65237.831079] snd_hda_codec snd_hda_core glue_helper snd_hwdep iTCO_wdt > > snd_seq iTCO_vendor_support snd_seq_device pcspkr snd_pcm sg i2c_i801 > > joydev wmi mei_me ipmi_si mei snd_timer acpi_power_meter ioatdma snd > > acpi_pad ipmi_devintf ipmi_msghandler soundcore lpc_ich nfsd auth_rpcgss > > nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod ast i2c_algo_bit > > drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm ixgbe > > ahci libahci crc32c_intel libata mdio i2c_core dca dm_mirror > > dm_region_hash dm_log dm_mod > > [65237.831109] CPU: 18 PID: 13897 Comm: fio Kdump: loaded Tainted: G > > OE 4.18.0-rc1+ #1 > > [65237.831110] Hardware name: Supermicro Super Server/X11DPG-QT, BIOS 1.0 > > 06/22/2017 > > [65237.831112] RIP: 0010:__list_add_valid+0x6a/0x70 > > [65237.831112] Code: 31 c0 48 c7 c7 90 08 ab a0 e8 22 b4 cd ff 0f 0b 31 c0 > > c3 48 89 d1 48 c7 c7 40 08 ab a0 48 89 f2 48 89 c6 31 c0 e8 06 b4 cd ff > > <0f> 0b 31 c0 c3 90 48 8b 07 48 b9 00 01 00 00 00 00 ad de 48 8b 57 > > [65237.831130] RSP: 0018:ffffbb1d0a41fdd8 EFLAGS: 00010286 > > [65237.831131] RAX: 0000000000000000 RBX: ffff94d0ebf90000 RCX: > > 0000000000000006 > > [65237.831132] RDX: 0000000000000000 RSI: 0000000000000086 RDI: > > ffff94d91ec16970 > > [65237.831132] RBP: ffffdb1cff59e980 R08: 0000000000000000 R09: > > 0000000000000663 > > [65237.831133] R10: 0000000000000004 R11: 0000000000000000 R12: > > 0000000000000001 > > [65237.831134] R13: 0000000000000000 R14: ffff94d0f0c57240 R15: > > ffff94d0f0f04c40 > > [65237.831135] FS: 00007fad10d02740(0000) GS:ffff94d91ec00000(0000) > > knlGS:0000000000000000 > > [65237.831135] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [65237.831136] CR2: 00007fad10c2a004 CR3: 000000085600e006 CR4: > > 00000000007606e0 > > [65237.831137] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > > 0000000000000000 > > [65237.831138] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > > 0000000000000400 > > [65237.831138] PKRU: 55555554 > > [65237.831138] Call Trace: > > [65237.831145] blk_mq_flush_plug_list+0x12d/0x260 > > [65237.831150] blk_flush_plug_list+0xe7/0x240 > > [65237.831152] blk_finish_plug+0x27/0x40 > > [65237.831156] __x64_sys_io_submit+0xc9/0x180 > > [65237.831162] do_syscall_64+0x5b/0x180 > > [65237.831166] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > I guess we need to clean list after list_splice_tail in the 1/1 patch as following > @@ -1533,19 +1533,19 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, > struct list_head *list) > > { > ... > + > + spin_lock(&ctx->lock); > + list_splice_tail(list, &ctx->rq_list); > + INIT_LIST_HEAD(list); // ---> HERE ! > blk_mq_hctx_mark_pending(hctx, ctx); > spin_unlock(&ctx->lock); Right. Kashyap, could you test the following patch? diff --git a/block/blk-mq.c b/block/blk-mq.c index 2f20c9e3efda..7d972b1c3153 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1567,7 +1567,7 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, } spin_lock(&ctx->lock); - list_splice_tail(list, &ctx->rq_list); + list_splice_tail_init(list, &ctx->rq_list); blk_mq_hctx_mark_pending(hctx, ctx); spin_unlock(&ctx->lock); } Thanks, Ming