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Fri, 8 Nov 2024 17:00:19 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id DyUxLaNDLme2NQAAD6G6ig (envelope-from ); Fri, 08 Nov 2024 17:00:19 +0000 Message-ID: <3c599659-d4b2-4e4b-8086-0925dd6b2c4e@suse.cz> Date: Fri, 8 Nov 2024 18:00:19 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: slab warning: kmem_cache of name 'dm_bufio_buffer' already exists Content-Language: en-US To: Yang Shi Cc: Mikulas Patocka , Pedro Falcato , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , zkabelac@redhat.com, Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org References: <9c3fecc3-19dc-42d4-6c89-4a48e9ad19cc@redhat.com> <5a1e67c3-481e-4c6e-8507-5a8ea0bd9f28@suse.cz> From: Vlastimil Babka Autocrypt: addr=vbabka@suse.cz; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSBWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBzdXNlLmN6PsLBlAQTAQoAPgIbAwULCQgHAwUVCgkICwUWAgMBAAIe AQIXgBYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJkBREIBQkRadznAAoJECJPp+fMgqZkNxIQ ALZRqwdUGzqL2aeSavbum/VF/+td+nZfuH0xeWiO2w8mG0+nPd5j9ujYeHcUP1edE7uQrjOC Gs9sm8+W1xYnbClMJTsXiAV88D2btFUdU1mCXURAL9wWZ8Jsmz5ZH2V6AUszvNezsS/VIT87 AmTtj31TLDGwdxaZTSYLwAOOOtyqafOEq+gJB30RxTRE3h3G1zpO7OM9K6ysLdAlwAGYWgJJ V4JqGsQ/lyEtxxFpUCjb5Pztp7cQxhlkil0oBYHkudiG8j1U3DG8iC6rnB4yJaLphKx57NuQ PIY0Bccg+r9gIQ4XeSK2PQhdXdy3UWBr913ZQ9AI2usid3s5vabo4iBvpJNFLgUmxFnr73SJ KsRh/2OBsg1XXF/wRQGBO9vRuJUAbnaIVcmGOUogdBVS9Sun/Sy4GNA++KtFZK95U7J417/J Hub2xV6Ehc7UGW6fIvIQmzJ3zaTEfuriU1P8ayfddrAgZb25JnOW7L1zdYL8rXiezOyYZ8Fm ZyXjzWdO0RpxcUEp6GsJr11Bc4F3aae9OZtwtLL/jxc7y6pUugB00PodgnQ6CMcfR/HjXlae h2VS3zl9+tQWHu6s1R58t5BuMS2FNA58wU/IazImc/ZQA+slDBfhRDGYlExjg19UXWe/gMcl De3P1kxYPgZdGE2eZpRLIbt+rYnqQKy8UxlszsBNBFsZNTUBCACfQfpSsWJZyi+SHoRdVyX5 J6rI7okc4+b571a7RXD5UhS9dlVRVVAtrU9ANSLqPTQKGVxHrqD39XSw8hxK61pw8p90pg4G /N3iuWEvyt+t0SxDDkClnGsDyRhlUyEWYFEoBrrCizbmahOUwqkJbNMfzj5Y7n7OIJOxNRkB IBOjPdF26dMP69BwePQao1M8Acrrex9sAHYjQGyVmReRjVEtv9iG4DoTsnIR3amKVk6si4Ea X/mrapJqSCcBUVYUFH8M7bsm4CSxier5ofy8jTEa/CfvkqpKThTMCQPNZKY7hke5qEq1CBk2 wxhX48ZrJEFf1v3NuV3OimgsF2odzieNABEBAAHCwXwEGAEKACYCGwwWIQSpQNQ0mSwujpkQ PVAiT6fnzIKmZAUCZAUSmwUJDK5EZgAKCRAiT6fnzIKmZOJGEACOKABgo9wJXsbWhGWYO7mD 8R8mUyJHqbvaz+yTLnvRwfe/VwafFfDMx5GYVYzMY9TWpA8psFTKTUIIQmx2scYsRBUwm5VI EurRWKqENcDRjyo+ol59j0FViYysjQQeobXBDDE31t5SBg++veI6tXfpco/UiKEsDswL1WAr tEAZaruo7254TyH+gydURl2wJuzo/aZ7Y7PpqaODbYv727Dvm5eX64HCyyAH0s6sOCyGF5/p eIhrOn24oBf67KtdAN3H9JoFNUVTYJc1VJU3R1JtVdgwEdr+NEciEfYl0O19VpLE/PZxP4wX PWnhf5WjdoNI1Xec+RcJ5p/pSel0jnvBX8L2cmniYnmI883NhtGZsEWj++wyKiS4NranDFlA HdDM3b4lUth1pTtABKQ1YuTvehj7EfoWD3bv9kuGZGPrAeFNiHPdOT7DaXKeHpW9homgtBxj 8aX/UkSvEGJKUEbFL9cVa5tzyialGkSiZJNkWgeHe+jEcfRT6pJZOJidSCdzvJpbdJmm+eED w9XOLH1IIWh7RURU7G1iOfEfmImFeC3cbbS73LQEFGe1urxvIH5K/7vX+FkNcr9ujwWuPE9b 1C2o4i/yZPLXIVy387EjA6GZMqvQUFuSTs/GeBcv0NjIQi8867H3uLjz+mQy63fAitsDwLmR EP+ylKVEKb0Q2A== In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Action: no action X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 85B24C0013 X-Stat-Signature: 8nycm9h9ffhpesgjdc9a3hzg4tthp1eg X-Rspam-User: X-HE-Tag: 1731085205-960798 X-HE-Meta: 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 0fohPrCe WzEN+Rw4klQlJ9uL+/1tWT8MWBv6M6Af0UOPFoR93Z3OpCbt1I4EehBTHiyYi/VfX9O9lhuMUnEeCzH5PRO4weE/RC4QPlwbSF3vng4RaQ8cSewnzRMtmn7L5C5nDmIYBDFXR2hK8UAiIj91FubKsJNg4z7IP5psXoCsEqq1GtduT3cP16WTcLQmuYCIV5IdnsEu4VtDxU2h8oWVVLXDcgt6OPpRmBsXHrkNuevg5lQ+0dooHZxUI2v/XfkYtdKv2hc/kxzv4Ftgi0oPfxQVVaDednVMrUrKWkiOslBVsLAdRJiMKEWK4hemL3NLNG397Os/lQNFR6bxRJ9M8R0HFb5hpqoA1s4ExgHrAD01UcdTvEiN97eKQ5S9ozA8lf8lcU7GUznchqtD9UeTBzhaijXPgfyAoQabw9czyo41O5spzXhhNcHFmkCKbqw== 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: List-Subscribe: List-Unsubscribe: On 11/8/24 17:49, Yang Shi wrote: > On Wed, Nov 6, 2024 at 3:35 AM Vlastimil Babka wrote: >> >> On 11/6/24 12:19, Mikulas Patocka wrote: >> > Hi >> >> Hi, >> >> > The commit 4c39529663b93165953ecf9b1a9ea817358dcd06 ("slab: Warn on >> > duplicate cache names when DEBUG_VM=y") is causing large number of >> > warnings about "dm_bufio_buffer", "dm_bufio_buffer-%u" (and other) device >> > mapper caches. >> >> Hmm wonder why nobody run into this before. We thought the code that would >> cause the warning would be all fixed before introducing it, but we missed >> some, sorry. > > Another data point, I also saw such warning when booting 6.12-rcX (rc1 > and rc6), but from mlx5 driver. I thought it was mlx driver specific > issue, it seems not. Well this particular issue is mlx driver specific. The caches it creates (per device?) don't seem to be have specific size or anything to that device, so it should be relatively simple to fix. > [ 63.537874] kmem_cache of name 'mlx5_fs_ftes' already exists > [ 63.546399] WARNING: CPU: 0 PID: 9 at mm/slab_common.c:107 > __kmem_cache_create_args+0xb4/0x330 > [ 63.557839] Modules linked in: vfat fat mlx5_core(+) dax_hmem > cxl_acpi ampere_cspmu cxl_port cxl_core mlxfw psample einj arm_spe_pmu > arm_cspmu_module tls pci_hyperv_intf acpi_ipmi acpi_tad ipmi_ssif > ipmi_devintf arm_cmn ipmi_msghandler cppc_cpufreq(+) fuse loop > nfnetlink zram xfs crct10dif_ce polyval_ce polyval_generic ghash_ce > sha3_ce nvme sha512_ce nvme_core sha512_arm64 sbsa_gwdt nvme_auth > xgene_hwmon > [ 63.596473] CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Tainted: G > W 6.12.0-rc6 #80 > [ 63.609156] Tainted: [W]=WARN > [ 63.614976] Hardware name: ZOLLNER SUNMOONLAKE/SunMoon Lake, BIOS > 00.00. 2024-10-30 13:48:02 11/06/2024 > [ 63.624359] Workqueue: events work_for_cpu_fn > [ 63.631569] pstate: 63400009 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) > [ 63.638523] pc : __kmem_cache_create_args+0xb4/0x330 > [ 63.646340] lr : __kmem_cache_create_args+0xb4/0x330 > [ 63.654158] sp : ffff800080d1bc00 > [ 63.660330] x29: ffff800080d1bc00 x28: 0000000000000000 x27: 0000000000000000 > [ 63.670318] x26: 0000000000000000 x25: ffffbf101f234410 x24: 00000000000002d8 > [ 63.677446] x23: 0000000000000000 x22: ffff800080d1bc58 x21: ffffbf101f2344b8 > [ 63.687436] x20: ffffbf0ff94870a8 x19: ffff2001053a1700 x18: 0000000000000014 > [ 63.694563] x17: 00000000a871ae29 x16: ffffbf101c282f18 x15: 000000007773661b > [ 63.704552] x14: 0000000000000000 x13: 7374736978652079 x12: 646165726c612027 > [ 63.714539] x11: 736574665f73665f x10: 35786c6d2720656d x9 : ffffbf101c1722f0 > [ 63.724531] x8 : ffff800080d1b890 x7 : 0000000000000001 x6 : 0000000000000001 > [ 63.734518] x5 : ffff001f7d803448 x4 : 0000000000000000 x3 : 0000000000000000 > [ 63.741646] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000108e3a440 > [ 63.751634] Call trace: > [ 63.754072] __kmem_cache_create_args+0xb4/0x330 > [ 63.761542] mlx5_fs_core_alloc+0x158/0x1a8 [mlx5_core] > [ 63.769708] mlx5_init_once+0x13c/0x520 [mlx5_core] > [ 63.777528] mlx5_init_one_devl_locked+0xa8/0x280 [mlx5_core] > [ 63.786127] probe_one+0xe0/0x200 [mlx5_core] > [ 63.790569] local_pci_probe+0x48/0xc0 > [ 63.794307] work_for_cpu_fn+0x24/0x40 > [ 63.798044] process_one_work+0x180/0x430 > [ 63.802042] worker_thread+0x25c/0x380 > [ 63.805778] kthread+0xf4/0x108 > [ 63.808907] ret_from_fork+0x10/0x20 > >> >> > I'd like to ask - how to properly fix it? >> > >> > We create a "dm_bufio_buffer" or "dm_bufio_buffer-%u" cache with every dm >> > bufio client. It used to work (and the duplicate caches are merged), but >> >> Note the merging can be disabled so then it's really several caches with >> exactly same name in /proc/slabinfo and inability to create their >> sysfs/debugfs directories. >> >> > now it warns. >> > >> > Should I append a pointer to the dm_bufio structure to the slab cache name >> > to make them different? Or is there any other preferred solution? >> >> Anything that uniquely identifies the client should be ok, but beware e.g. >> device names that can have slashes, see commit a360f311f57a36 (also for the >> simplest possible fix that is an incremented number). >> >> > Note that it is not possible to pre-create the cache "dm_bufio_buffer-%u" >> > in the module's init function, because the size of per-buffer auxiliary >> > data is not known at this point. >> >> Looks like some chose to solve this the harder way, see 4d784c042d164f >> >> > Mikulas >> > >> >>