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 09EADC27C75 for ; Tue, 11 Jun 2024 16:40:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 676D36B0083; Tue, 11 Jun 2024 12:40:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 626406B0093; Tue, 11 Jun 2024 12:40:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4C5CD6B0089; Tue, 11 Jun 2024 12:40:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 2F9936B0093 for ; Tue, 11 Jun 2024 12:40:56 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 92169A1F28 for ; Tue, 11 Jun 2024 16:40:55 +0000 (UTC) X-FDA: 82219172070.24.1CCB714 Received: from mail-lj1-f176.google.com (mail-lj1-f176.google.com [209.85.208.176]) by imf05.hostedemail.com (Postfix) with ESMTP id 8551E100018 for ; Tue, 11 Jun 2024 16:40:53 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=J+dnnsLC; spf=pass (imf05.hostedemail.com: domain of urezki@gmail.com designates 209.85.208.176 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1718124053; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Q3cp5cBt94hqMuZOiuslwcsypWMUhnJVnOEPMjj6Pe0=; b=wTghNV2JG1qDHzboLW/D1WQMBTuxN5gPIBHxGpf2dSYp1zY2MkRmbOoYeyGK6pS1pmPSF2 BV+CswE0R3yco2KQ19IISojbxFHInKvBQrDxATD50OJ5/nMDI4+DiuSvjEuF1YMHKQSbj5 ncgLa8zw4a3MSUwhFxqacADqVeTFPqk= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=J+dnnsLC; spf=pass (imf05.hostedemail.com: domain of urezki@gmail.com designates 209.85.208.176 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1718124053; a=rsa-sha256; cv=none; b=0yhKbWD9I9xYX5mVR2hfd6ySfXxE6Fq/TNdUVn10TXsqRnQRMCrnC4nn5LmC3HGBQXJjtj NV7CiHywHujfWEW81uNA/bVVZGHLqeMrC17ZYQeCQF4ZNljgnTlDE/l9RikjmFr4R8OWXV tRS4HBwDOFFLWGdW2SeTioaFVr2VWvQ= Received: by mail-lj1-f176.google.com with SMTP id 38308e7fff4ca-2ebed33cbafso21311761fa.1 for ; Tue, 11 Jun 2024 09:40:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1718124052; x=1718728852; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=Q3cp5cBt94hqMuZOiuslwcsypWMUhnJVnOEPMjj6Pe0=; b=J+dnnsLCIUbci1wSoF4VjcfuQrDxpyQVyCwztuQtchU42ontxq1mJNxh+OmXEZEqIS HxkxF2Il90m5vGfsr7u0e79HFTpA+o42yFbkUqaqG99G0lwjBPtpU3ZYBKPr/WhfYJJ5 pq39KuQ8ojy6PRaRDS4DbBIz+5wAfIMntJ62Alyahl5aHD+eaa+N012eXPCcvxwiDqLg I0l7jagroxGUxdFrNsOq1NiPYYeN4MY3vQoCUIyTPmGgd9m4I8dmYLSQcEmPGdF/qt7j PrPWrnyH1rNaiC6GS/VVx2N7bPEDSGBpKJJ4/VgRBYFkJB55Wu+DqVNrgkt417as3MSR RyEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718124052; x=1718728852; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Q3cp5cBt94hqMuZOiuslwcsypWMUhnJVnOEPMjj6Pe0=; b=DdsRPbwC+TLxOaoVeZGz1fvNokzEr2Pln6zKCFQQUfuKB4ruegtoIW1IStPHOXyhFb Una6QGnVxs7btnTCHYuxJ1ztd1VmsVKEkucM+2LNz/rdyl3wvJktu1+y5ePgUB0MOnNi myRdX7NQYgIVRl5LPuIfPkxxwb/W8Vyi5DyGerP/I1PrI0IA7PfACz7mNIM8nKOePayB 5lpGYVEfKh693t/aW/Ct6WRmfQLAYiYI0yA44T2C7a271D8Wwt0v0nkPVE9ltoUg3x2o EeDN38AGBCAUhInC4xRkc5TAgksx3SgoAQaIzhJgYgauWUvCfjLmLu6ZywKSnmm1Yq08 9cGw== X-Forwarded-Encrypted: i=1; AJvYcCVx4ySlyYV/bdq162pPdrNTZSZHX6flk9GhPUriphjeZio/NrVKfCMSEsjrZRa+XgjGylQo5XpjVbaSh2TLMlgEmk0= X-Gm-Message-State: AOJu0YyLomFjijTbwjPR4SwYeoLMJ+jRDAJN9jf1TT7AKrOvIhNwuijw qs61ghanHoymZ44CWW6rrT0dmkJu3xlnFm5p2qCkIiqx24TGUC+w X-Google-Smtp-Source: AGHT+IEbo3JpmZ5Ejf1Kjt4blYqXT4/XXSYFYE0gsw6Uo+iMJTP8Yyob5KSxpkPUQlraHuzFQ3p+Iw== X-Received: by 2002:a2e:9588:0:b0:2eb:d798:ba7c with SMTP id 38308e7fff4ca-2ebd798bc40mr54670691fa.52.1718124051308; Tue, 11 Jun 2024 09:40:51 -0700 (PDT) Received: from pc638.lan (host-185-121-47-193.sydskane.nu. [185.121.47.193]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-57c7ef8d914sm4589340a12.71.2024.06.11.09.40.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Jun 2024 09:40:50 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Tue, 11 Jun 2024 18:40:49 +0200 To: "Paul E. McKenney" , Julia Lawall Cc: Julia Lawall , Uladzislau Rezki , Vlastimil Babka , "linux-mm@kvack.org" , RCU , cocci@inria.fr Subject: Re: [cocci] patch idea: convert trivial call_rcu users to kfree_rcu Message-ID: References: <2dd5bafb-ceb1-238d-2f51-83ebf135b73@inria.fr> <2ec7eb0f-0950-4d65-b33a-64df7c5f89c9@paulmck-laptop> <77531e55-3418-d4be-f538-7ddc904ed88f@inria.fr> <21a32cbb-d388-4a8c-9298-ef8c82330f9e@paulmck-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <21a32cbb-d388-4a8c-9298-ef8c82330f9e@paulmck-laptop> X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 8551E100018 X-Stat-Signature: oceikecno3qwos64qwkceir9stasbt7f X-HE-Tag: 1718124053-496529 X-HE-Meta: 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 whOwou/f bMUu9NeEVZXe6+NflA2WN6mURg8NEyCvNaP44/ob+ZJ6TbW5Ykbq5zh1G4Ra7NcGq5DD0oMB20as5V7VJaZ+zk8Ks7x2Z/q+M9kWhpxUlHVajJRgk3ZKhkzRYaHwa+Ut0bVZg2yVixK/ajugKiXUkwLL/tVt/CoGPFW3+t4nTRkn7mIRx1b/YXUz6llZhSKyYezMsDepKdep9RQqwgqzCH7MtP2yKlXvdM3mfiRBN7jEkIHNF75KmxPRwUDkYRknLDiCkh/hx6gbvbGo5Uh/+ZYMGVNCaxqIRKMhkndVn3nt0Nw1eGYlJKW0xipH3l/B9Pg5ATe+VSZMB740ud/uyPF6do1K55SvJfdg7iOHMKnu8mjgiWNOQJs3otfFv9m0Ur76F 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: > > > > These look ok to me. In the last two cases, the callback function is also > > stored in a data structure, eg: > > > > static struct mfc6_cache *ip6mr_cache_alloc(void) > > { > > struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL); > > if (!c) > > return NULL; > > c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1; > > c->_c.mfc_un.res.minvif = MAXMIFS; > > c->_c.free = ip6mr_cache_free_rcu; > > refcount_set(&c->_c.mfc_un.res.refcount, 1); > > return c; > > } > > > > Should that be left as it is? > > Given that ->_c.free isn't used in the RCU callback, I am guessing that > this is intended for debugging purposes, so that you can see from a crash > dump how this will be freed. But I could be completely off-base here. > > One approach would be to remove the ->_c.free field and call attention > to this in the patches' commit logs. > > Another would be to instead put the address of the allocation function > in ->_c.free, and again call attention to this in the commit logs. > > Is there a better approach than these three? ;-) > IMO, "_c.free" should be removed: diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h index 9dd4bf157255..45f220f761df 100644 --- a/include/linux/mroute_base.h +++ b/include/linux/mroute_base.h @@ -130,7 +130,6 @@ enum { * @refcount: reference count for this entry * @list: global entry list * @rcu: used for entry destruction - * @free: Operation used for freeing an entry under RCU */ struct mr_mfc { struct rhlist_head mnode; @@ -156,13 +155,12 @@ struct mr_mfc { } mfc_un; struct list_head list; struct rcu_head rcu; - void (*free)(struct rcu_head *head); }; static inline void mr_cache_put(struct mr_mfc *c) { if (refcount_dec_and_test(&c->mfc_un.res.refcount)) - call_rcu(&c->rcu, c->free); + kfree_rcu(c, rcu); } static inline void mr_cache_hold(struct mr_mfc *c) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 6c750bd13dd8..5d2e339f09cc 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -702,16 +702,9 @@ static int vif_delete(struct mr_table *mrt, int vifi, int notify, return 0; } -static void ipmr_cache_free_rcu(struct rcu_head *head) -{ - struct mr_mfc *c = container_of(head, struct mr_mfc, rcu); - - kmem_cache_free(mrt_cachep, (struct mfc_cache *)c); -} - static void ipmr_cache_free(struct mfc_cache *c) { - call_rcu(&c->_c.rcu, ipmr_cache_free_rcu); + kfree_rcu(c, _c.rcu); } /* Destroy an unresolved cache entry, killing queued skbs @@ -959,7 +952,6 @@ static struct mfc_cache *ipmr_cache_alloc(void) if (c) { c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1; c->_c.mfc_un.res.minvif = MAXVIFS; - c->_c.free = ipmr_cache_free_rcu; refcount_set(&c->_c.mfc_un.res.refcount, 1); } return c; diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index dd342e6ecf3f..1634fa794ea2 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -753,16 +753,9 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, return 0; } -static inline void ip6mr_cache_free_rcu(struct rcu_head *head) -{ - struct mr_mfc *c = container_of(head, struct mr_mfc, rcu); - - kmem_cache_free(mrt_cachep, (struct mfc6_cache *)c); -} - static inline void ip6mr_cache_free(struct mfc6_cache *c) { - call_rcu(&c->_c.rcu, ip6mr_cache_free_rcu); + kfree_rcu(c, _c.rcu); } /* Destroy an unresolved cache entry, killing queued skbs @@ -985,7 +978,6 @@ static struct mfc6_cache *ip6mr_cache_alloc(void) return NULL; c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1; c->_c.mfc_un.res.minvif = MAXMIFS; - c->_c.free = ip6mr_cache_free_rcu; refcount_set(&c->_c.mfc_un.res.refcount, 1); return c; } -- Uladzislau Rezki