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 CB8FAE66885 for ; Sat, 23 Nov 2024 21:39:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 62ABA6B0085; Sat, 23 Nov 2024 16:39:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5DA586B0088; Sat, 23 Nov 2024 16:39:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 453D06B0089; Sat, 23 Nov 2024 16:39:04 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 212546B0085 for ; Sat, 23 Nov 2024 16:39:04 -0500 (EST) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 92420A0405 for ; Sat, 23 Nov 2024 21:39:03 +0000 (UTC) X-FDA: 82818675324.25.6DFD76D Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf29.hostedemail.com (Postfix) with ESMTP id 77AF9120019 for ; Sat, 23 Nov 2024 21:38:59 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=sdoFYVrS; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=5+JrooF9; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=sdoFYVrS; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=5+JrooF9; spf=pass (imf29.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 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=1732397940; 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=6UWRK3U2kwjrPDNkOYQpWf3bDm/UCvDWvz7vqXvn/og=; b=DsJH9uqKpTRvQPp4RSUkDC36tiMnX57/wEilMmaR3Vti3jqPz+4dGU04hLkYaQ0zhNB0WV 6872qATlp/W+bAqU5vUFvTYDJuAzKmS/Kt2C/M2WnEQDSMojV2V4lJzkNs53Vay66vyZul 7dUtiQujw+vYYWfZOqXe3kxUHW5oCwY= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=sdoFYVrS; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=5+JrooF9; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=sdoFYVrS; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=5+JrooF9; spf=pass (imf29.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1732397940; a=rsa-sha256; cv=none; b=PkJlxAcLYtwp6BuA88UoZouHCNaEJ705ES19xmhPVTuU+mdNEm11II5o46szseobhsvEmO PEALdS2hAZnLA6jL87I80vu9Lg9jfT/ZX+182FjI5ZhsxtETydUtUztHbEfzTEw8+cQ4O9 n/CIbZ8kZU5CSQ0FKcNR/IE/X/TfDXI= 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-out1.suse.de (Postfix) with ESMTPS id 862E72122E; Sat, 23 Nov 2024 21:38:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1732397939; 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=6UWRK3U2kwjrPDNkOYQpWf3bDm/UCvDWvz7vqXvn/og=; b=sdoFYVrSFMI6RuyvDePk4jP7NU9w3fGKNBvyIzzNjONU8/bg0B3LyCR8OgPxe9hdrnOAnt 7C/0baBG5l4OjFh85CUPRjuuxaBvJM6kmdg78Ij4g9qd0VUve/P4Tp9LII/cc+G1ulSqIs x0Uss5SGAPrUMawMz3tvyY3759MAkPA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1732397939; 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=6UWRK3U2kwjrPDNkOYQpWf3bDm/UCvDWvz7vqXvn/og=; b=5+JrooF9ZKRH1Bi+ml0N4rfPBV2SKfD+4VZKp1mthSfgG4nW4m34cqoVV2NGxM0z3w+zvB CCdceZcEPAxw+OAQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1732397939; 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=6UWRK3U2kwjrPDNkOYQpWf3bDm/UCvDWvz7vqXvn/og=; b=sdoFYVrSFMI6RuyvDePk4jP7NU9w3fGKNBvyIzzNjONU8/bg0B3LyCR8OgPxe9hdrnOAnt 7C/0baBG5l4OjFh85CUPRjuuxaBvJM6kmdg78Ij4g9qd0VUve/P4Tp9LII/cc+G1ulSqIs x0Uss5SGAPrUMawMz3tvyY3759MAkPA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1732397939; 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=6UWRK3U2kwjrPDNkOYQpWf3bDm/UCvDWvz7vqXvn/og=; b=5+JrooF9ZKRH1Bi+ml0N4rfPBV2SKfD+4VZKp1mthSfgG4nW4m34cqoVV2NGxM0z3w+zvB CCdceZcEPAxw+OAQ== 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 646E713A6E; Sat, 23 Nov 2024 21:38:59 +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 o1fdF3NLQmcPSAAAD6G6ig (envelope-from ); Sat, 23 Nov 2024 21:38:59 +0000 Message-ID: Date: Sat, 23 Nov 2024 22:38:59 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: mmap_lock: optimize mmap_lock tracepoints To: Shakeel Butt , Matthew Wilcox Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Axel Rasmussen , Steven Rostedt , Suren Baghdasaryan , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team References: <20241123060939.169978-1-shakeel.butt@linux.dev> Content-Language: en-US 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-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 77AF9120019 X-Stat-Signature: d6meqhjfed5krg44e8tb9ki381d6yeqj X-Rspam-User: X-HE-Tag: 1732397939-484861 X-HE-Meta: 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 TeN4ZGNc LnS2m627nw906XhoLY/KzJ1nbwNgqNyFVF5ED4fRlEcDpRZpXJeCBr8qvLVfy2gU2GI61ZIG5xQGxPaCXN7GfPiE5bR0aM3k7Hs2hP1AeO9j4trfAF3KZBUGE4JW6NNt13trNByDrXK3ZbkEL+Uvo8+8ncaQTwm5UZK04D7eXhTcRmzmhoRSsFKJ3LPc0l5wYCG3Hx73B3y6BaSv2YnZ7vSD1mhc57D0blD1RTMi9n9czAqA1prm4sCtvAIShBaUZgPFWwQKEsBbM8R1UKSLihEVbV2YC5Aw28qK2+N4HV2IazVXQFeVvdbgc3F8iN71K/BFiaOouRsKejjBEGyK9EZd/4g== 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 11/23/24 22:35, Shakeel Butt wrote: > On Sat, Nov 23, 2024 at 05:01:57PM +0000, Matthew Wilcox wrote: >> On Fri, Nov 22, 2024 at 10:09:39PM -0800, Shakeel Butt wrote: >> > TP_printk( >> > - "mm=%p memcg_path=%s write=%s", >> > - __entry->mm, >> > - __get_str(memcg_path), >> > + "mm=%p memcg_id=%llu write=%s", >> > + __entry->mm, __entry->memcg_id, >> > __entry->write ? "true" : "false" >> >> Is it actually useful to print out the (hashed) pointer of the mm? >> Wouldn't the PID be more useful so you could actually associate it with >> a task? >> > > For our usecase i.e. bpftrace, we don't really care about these prints > as we can directly access the arguments like mm in bpftrace. I wonder if > others are using this hased pointer in some other way. I don't mind > chaning it but I think that would be a separate patch. I wonder if it's actually hashed when trace events are obtained in binary form, i.e. via trace-cmd. Might be hashed only when doing e.g. cat trace_pipe as that's when the kernel's printk with its hashing is used? I guess that would be another argument for not using it in the tracepoint, as it would be a sidechannel...