What does the kernel warning "workqueue: WQ_MEM_RECLAIM <workqueue name>:<function name> is flushing !WQ_MEM_RECLAIM <workqueue name>:<function name>" mean?

Issue

• The kernel shows a warning message similar to the following:

kernel: workqueue: WQ_MEM_RECLAIM writeback:wb_workfn is flushing !WQ_MEM_RECLAIM events:0x0
kernel: WARNING: CPU: 11 PID: 3062908 at kernel/workqueue.c:2602 check_flush_dependency+0x110/0x130
kernel: Modules linked in: clpka(OE) clpkhb(OE) liscal(OE) xt_CHECKSUM ipt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink tun bridge stp llc bonding mpt3sas raid_class scsi_transport_sas dell_rbu sunrpc vfat fat intel_rapl_msr intel_rapl_common isst_if_common skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass dell_smbios dcdbas dell_wmi_descriptor crct10dif_pclmul crc32_pclmul ghash_clmulni_intel iTCO_wdt iTCO_vendor_support rapl wmi_bmof intel_cstate joydev intel_uncore pcspkr ipmi_ssif mei_me i2c_i801 lpc_ich mei acpi_ipmi wmi ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter binfmt_misc ip_tables xfs libcrc32c sr_mod cdrom sd_mod t10_pi sg mgag200 drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 megaraid_sas crc32c_intel i2c_algo_bit dm_mirror dm_region_hash dm_log dm_mod fuse
kernel: CPU: 11 PID: 3062908 Comm: kworker/u40:4 Tainted: GF         IOE    --------- -  - 4.18.0-305.el8.x86_64 #1
kernel: Hardware name: Dell Inc. PowerEdge R440/04JN2K, BIOS 2.12.2 07/09/2021
kernel: Workqueue: writeback wb_workfn (flush-218:2)
kernel: RIP: 0010:check_flush_dependency+0x110/0x130
kernel: Code: ff ff 48 8b 50 18 48 8d 8b b0 00 00 00 49 89 e8 48 81 c6 b0 00 00 00 48 c7 c7 98 c4 eb a2 c6 05 dc 50 6d 01 01 e8 f9 3f fe ff <0f> 0b e9 0a ff ff ff 80 3d ca 50 6d 01 00 75 95 e9 41 ff ff ff 66
kernel: RSP: 0018:ffffb150c9be3748 EFLAGS: 00010286
kernel: RAX: 0000000000000000 RBX: ffff943607c19000 RCX: 0000000000000000
kernel: RDX: 0000000000000054 RSI: ffffffffa3cb8f34 RDI: 0000000000000246
kernel: RBP: 0000000000000000 R08: ffffffffa3cb8ee0 R09: 0000000000029700
kernel: R10: 02858c3cfdefd36e R11: 00000000002ebc7c R12: ffff943600be8000
kernel: R13: 0000000000000001 R14: ffffffffc0c02e28 R15: ffffb150c9be3790
kernel: FS:  0000000000000000(0000) GS:ffff944d1bec0000(0000) knlGS:0000000000000000
kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 00007fe617938020 CR3: 0000000302e10004 CR4: 00000000007706e0
kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kernel: PKRU: 55555554
kernel: Call Trace:
kernel: flush_workqueue+0x13a/0x440
kernel: liscal_make_request+0x4cf/0x8e0 [liscal]
kernel: generic_make_request+0xed/0x340
kernel: submit_bio+0x3c/0x160
kernel: iomap_submit_ioend.isra.38+0x4a/0x70
kernel: iomap_writepage_map+0x45b/0x6b0
kernel: write_cache_pages+0x197/0x420
kernel: ? iomap_invalidatepage+0xe0/0xe0
kernel: iomap_writepages+0x1c/0x40
kernel: xfs_vm_writepages+0x64/0x90 [xfs]
kernel: do_writepages+0x41/0xd0
kernel: __writeback_single_inode+0x3d/0x370
kernel: writeback_sb_inodes+0x1e6/0x450
kernel: __writeback_inodes_wb+0x5f/0xc0
kernel: wb_writeback+0x25b/0x2f0
kernel: ? get_nr_inodes+0x35/0x50
kernel: wb_workfn+0x37a/0x4c0
kernel: process_one_work+0x1a7/0x360
kernel: ? create_worker+0x1a0/0x1a0
kernel: worker_thread+0x30/0x390
kernel: ? create_worker+0x1a0/0x1a0
kernel: kthread+0x116/0x130
kernel: ? kthread_flush_work_fn+0x10/0x10
kernel: ret_from_fork+0x1f/0x40