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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E286C3DA59 for ; Fri, 19 Jul 2024 10:10:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B67FF6B0083; Fri, 19 Jul 2024 06:10:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B18506B0089; Fri, 19 Jul 2024 06:10:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 991786B0088; Fri, 19 Jul 2024 06:10:19 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 7D3346B0082 for ; Fri, 19 Jul 2024 06:10:19 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 2306B40589 for ; Fri, 19 Jul 2024 10:10:19 +0000 (UTC) X-FDA: 82356082158.14.1C99531 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) by imf05.hostedemail.com (Postfix) with ESMTP id 97FDE10002E for ; Fri, 19 Jul 2024 10:10:16 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=TJbPcSk4; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b="gs/ez3gW"; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=fsbhFjcF; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=m36JJmAI; spf=pass (imf05.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.131 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1721383795; a=rsa-sha256; cv=none; b=b50A2f9ib9xb0n0Yn8bI3DCzutw2SZo2f95aCxio82D7oXhjnCaX2KF0RizL7aDX6OT8kl mFp/ilMCQh1RGwkWV+GF59l2Pen3X1uq1t/tR2mfP1B5rn+r9ulY88A61m9YOnLBQ1W6Tn /vdFyV25yZkFt66NogJwGwlkYVMvfNg= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=TJbPcSk4; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b="gs/ez3gW"; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=fsbhFjcF; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=m36JJmAI; spf=pass (imf05.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.131 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1721383795; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/FRWgPel8HXCxjBkez+iUxzkiwFkguVK4GNErIGAhDk=; b=k1fzGnp2MjKd5B31gXUvRDq5zYPdUfThOGTzAMcsukz801Nx4iu6MqVREP/gmuU2JDSgV9 IWHoLDQimmkb+IJCA1mjJpsHFXJ5NPEeLV9CrfNoFQQZ0B2nyXC49jVF7qT0cNSfehhexR 0vCxvwKf7SFq/+BrrhBnS5/ST2YEjew= Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 914F31F79C; Fri, 19 Jul 2024 10:10:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1721383814; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=/FRWgPel8HXCxjBkez+iUxzkiwFkguVK4GNErIGAhDk=; b=TJbPcSk4DqhLiTIO7Js6SSukPGRc9meBW/5/Vw67glyW1oKWOS579WrKsIfRPhun3H9imw VyH7nJYXr4m3l4++FrTXHtClt2KGbiy9F+oomZb0hegYTF30h8PnbFwk6bvxpgmUFjNkJl Bd5PjxF0FWYG55WVIE6hROk8wF2M1Nk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1721383814; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=/FRWgPel8HXCxjBkez+iUxzkiwFkguVK4GNErIGAhDk=; b=gs/ez3gWb/2gH2qPB66v1DXdhZXT+bAWQcz/8y8TZA2FpuyRH9S9PPQd/YtP/iFVfoAv1i DYRqsJFb+iZTP8Aw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1721383813; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=/FRWgPel8HXCxjBkez+iUxzkiwFkguVK4GNErIGAhDk=; b=fsbhFjcFvUQH+oMwY/2CruqarSQHZ/pxuwB5pL0kalhqfnLntGk4p311cp5zVTYG0btXsk SiEv3dR2WeHMcbnd+UAB3mFT9np9eY+40/4owy1etf5ZZ3aEAz5uLf8ppvcxRKlxhXodqq 6LSFqGmU9ABwlj9BNh8IskN6B4OiIqY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1721383813; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=/FRWgPel8HXCxjBkez+iUxzkiwFkguVK4GNErIGAhDk=; b=m36JJmAIC/AAIu3rrDc/2ccOjZZW6RG/e5b2fb2j0nTsVR0TYxea8wyX1Ky/8nOZMY+TW1 H03AfHc46n31HACA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 757D4132CB; Fri, 19 Jul 2024 10:10:13 +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 hlRWHIU7mmbWUwAAD6G6ig (envelope-from ); Fri, 19 Jul 2024 10:10:13 +0000 Message-ID: <031ff35b-65f0-4ead-a08f-21711bad5e29@suse.cz> Date: Fri, 19 Jul 2024 12:10:13 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC] mm: warn potential return NULL for kmalloc_array and kvmalloc_array with __GFP_NOFAIL Content-Language: en-US To: Michal Hocko Cc: Barry Song <21cnbao@gmail.com>, akpm@linux-foundation.org, linux-mm@kvack.org, Barry Song , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com> References: 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: 7bit X-Stat-Signature: ctw5gu7abpaxd43o67sspw9hib6wfryn X-Rspamd-Queue-Id: 97FDE10002E X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1721383816-481851 X-HE-Meta: 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 C0M6bRBO 2nSun5e9IeAbsWhqqDaKRDoOtSgKVBmDAf3XulA+qfzD7yjOx0lq4ZQCZZzxu2HCywq6RjwEqWMd31D/qZX8vw5+eUzOGMSJhtCstRA2LwwveQ6h4WvfrNPX7Qpq229uwpGP26Of72sW2B/T/Lp+XQSPU+YOOdKwX1wDwQCS3GBxfmLu6iE7mprT17BFx5J9K6Lr6gBNLJtyHTzvz0D7qJMMUpkuflVKPnEBAYa5Cvhb7FwBk+u7xDdnI2g937vhRq9bUMhi4SpotBkvEolvISy0rodU1Iw95nRVx7hbkdKOLRTesFCDPQz022GTWxFxRi/9kMvWPejS3WSIQwvNeO71dL66QNh6yFvQsQNlDGWrC1o9cJFZfvicj0fm9+rGwztI+ 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 7/19/24 11:33 AM, Michal Hocko wrote: > On Fri 19-07-24 10:50:07, Vlastimil Babka wrote: > [...] >> That wouldn't mean the busy loop is a correct and supported practice. It >> would just mean it's the least bad of the bad options we have to deal with >> an allocation that's wrong but we didn't catch soon enough in the development. > > So you want to make those potential BUG_ONs hard/soft lockups (not sure > all arches have a reliable detection) instead? I'd expect on a SMP machine there's fair chance of being rescued by kswapd or other direct reclaimer.