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 X-Spam-Level: X-Spam-Status: No, score=-9.3 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FA19C8300A for ; Tue, 28 Apr 2020 20:59:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BDEAE20B80 for ; Tue, 28 Apr 2020 20:59:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fBNRUevw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BDEAE20B80 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 62ED68E000A; Tue, 28 Apr 2020 16:59:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5B8ED8E0007; Tue, 28 Apr 2020 16:59:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D08B8E000A; Tue, 28 Apr 2020 16:59:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0245.hostedemail.com [216.40.44.245]) by kanga.kvack.org (Postfix) with ESMTP id 2AFBE8E0007 for ; Tue, 28 Apr 2020 16:59:36 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D8A99181AC9C6 for ; Tue, 28 Apr 2020 20:59:35 +0000 (UTC) X-FDA: 76758479910.26.milk27_53c26643e9b51 X-HE-Tag: milk27_53c26643e9b51 X-Filterd-Recvd-Size: 6967 Received: from mail-lj1-f194.google.com (mail-lj1-f194.google.com [209.85.208.194]) by imf21.hostedemail.com (Postfix) with ESMTP for ; Tue, 28 Apr 2020 20:59:35 +0000 (UTC) Received: by mail-lj1-f194.google.com with SMTP id a21so202302ljb.9 for ; Tue, 28 Apr 2020 13:59:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=sSPDLCw928vWc9z2Vz2mWvGeAMzP8/jPehX8Io29R/M=; b=fBNRUevwPDJSM6q61fYhtsse5IE6E2y49tzY82VPIID1sRrr24Y4C3aaCE9B4T1ysJ mOluuoskKtW7BHBxKOgr9NHqfsm0tFoVS2yZiEKTY/jXHX2nvMQJlIcXwoKnTU43WNfI rfVhpIDwCGbdAbrwRJ9hnIG8ov2eLEn5/PxoYgnyh9/NCqjGM8OvzN5YXwHuOgpPQudb wXIItywWBp9ndAHZ5asj6ggkGlspU+FNJ1tWf1RJ3hfOwwS6RF5xvPHNaI/EBRqoATpG oLR9O8UiOtqpy4TSULHeReidBctk5DOOnqlEdLtR8zvnc2ZMQj6x1wnzz/ToBD3zaXP6 HgoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=sSPDLCw928vWc9z2Vz2mWvGeAMzP8/jPehX8Io29R/M=; b=IKLDk98opykoIHrqSp2efaAzQ+zdQNIeDZg7RnADk6zXoHgI3Df5QZUhyUvpR+sgKm +a9IK0qcIlV5mGMnBRWNsWDat7tLq9SFt2zrqiFxVvScaSnNOIFKwDzjBjjgHvUDpMHr xkbFyQ+XHQDC/pzo4EYV2K9/mr+Vqj4gY4guAa2GgZinSDxBkcjGPb/AAasXA+ptE6D0 vp9I494y8dc0VpKDmVGAmjesbTU5XEh1JmtcZPIJExd0Tr9FOJz6eIbdjOipPc8QbZbA vYrtmHM58m8YOxkVu9rdnfR1z168njJ1JHkvt195mcS47qbq21fUDVsKg35XnaKsIStb QZZw== X-Gm-Message-State: AGi0PuYbipjGFW5Zkt9lOUL2KnxCYdJ7wazbXT2OctrAiEF6mjpwF5a2 J38VMQAoSxjZIo03hDzA6PY= X-Google-Smtp-Source: APiQypJOSkeM4KBluNbofCs+yZeBUUC4FcCWL6GUCvKOg8yk0RnaTVgUFbftNLX0tMsTwccEtDwwkw== X-Received: by 2002:a2e:b5d2:: with SMTP id g18mr18864979ljn.51.1588107574209; Tue, 28 Apr 2020 13:59:34 -0700 (PDT) Received: from pc638.lan (h5ef52e31.seluork.dyn.perspektivbredband.net. [94.245.46.49]) by smtp.gmail.com with ESMTPSA id z21sm295483ljh.42.2020.04.28.13.59.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Apr 2020 13:59:33 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: LKML , linux-mm@kvack.org Cc: Andrew Morton , "Paul E . McKenney" , "Theodore Y . Ts'o" , Matthew Wilcox , Joel Fernandes , RCU , Uladzislau Rezki , Oleksiy Avramchenko Subject: [PATCH 05/24] rcu/tree: Simplify debug_objects handling Date: Tue, 28 Apr 2020 22:58:44 +0200 Message-Id: <20200428205903.61704-6-urezki@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200428205903.61704-1-urezki@gmail.com> References: <20200428205903.61704-1-urezki@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: From: "Joel Fernandes (Google)" In order to prepare for future changes for headless RCU support, make the debug_objects handling in kfree_rcu use the final 'pointer' value of the object, instead of depending on the head. Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Joel Fernandes (Google) --- kernel/rcu/tree.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 0762ac06f0b7..767aed49d7fd 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2860,13 +2860,11 @@ EXPORT_SYMBOL_GPL(call_rcu); * @nr_records: Number of active pointers in the array * @records: Array of the kfree_rcu() pointers * @next: Next bulk object in the block chain - * @head_free_debug: For debug, when CONFIG_DEBUG_OBJECTS_RCU_HEAD is se= t */ struct kfree_rcu_bulk_data { unsigned long nr_records; void *records[KFREE_BULK_MAX_ENTR]; struct kfree_rcu_bulk_data *next; - struct rcu_head *head_free_debug; }; =20 /** @@ -2916,11 +2914,13 @@ struct kfree_rcu_cpu { static DEFINE_PER_CPU(struct kfree_rcu_cpu, krc); =20 static __always_inline void -debug_rcu_head_unqueue_bulk(struct rcu_head *head) +debug_rcu_bhead_unqueue(struct kfree_rcu_bulk_data *bhead) { #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD - for (; head; head =3D head->next) - debug_rcu_head_unqueue(head); + int i; + + for (i =3D 0; i < bhead->nr_records; i++) + debug_rcu_head_unqueue((struct rcu_head *)(bhead->records[i])); #endif } =20 @@ -2950,7 +2950,7 @@ static void kfree_rcu_work(struct work_struct *work= ) for (; bhead; bhead =3D bnext) { bnext =3D bhead->next; =20 - debug_rcu_head_unqueue_bulk(bhead->head_free_debug); + debug_rcu_bhead_unqueue(bhead); =20 rcu_lock_acquire(&rcu_callback_map); trace_rcu_invoke_kfree_bulk_callback(rcu_state.name, @@ -2972,14 +2972,15 @@ static void kfree_rcu_work(struct work_struct *wo= rk) */ for (; head; head =3D next) { unsigned long offset =3D (unsigned long)head->func; + void *ptr =3D (void *)head - offset; =20 next =3D head->next; - debug_rcu_head_unqueue(head); + debug_rcu_head_unqueue((struct rcu_head *)ptr); rcu_lock_acquire(&rcu_callback_map); trace_rcu_invoke_kfree_callback(rcu_state.name, head, offset); =20 if (!WARN_ON_ONCE(!__is_kfree_rcu_offset(offset))) - kfree((void *)head - offset); + kfree(ptr); =20 rcu_lock_release(&rcu_callback_map); cond_resched_tasks_rcu_qs(); @@ -3118,18 +3119,11 @@ kfree_call_rcu_add_ptr_to_bulk(struct kfree_rcu_c= pu *krcp, /* Initialize the new block. */ bnode->nr_records =3D 0; bnode->next =3D krcp->bhead; - bnode->head_free_debug =3D NULL; =20 /* Attach it to the head. */ krcp->bhead =3D bnode; } =20 -#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD - head->func =3D func; - head->next =3D krcp->bhead->head_free_debug; - krcp->bhead->head_free_debug =3D head; -#endif - /* Finally insert. */ krcp->bhead->records[krcp->bhead->nr_records++] =3D (void *) head - (unsigned long) func; @@ -3153,14 +3147,17 @@ void kfree_call_rcu(struct rcu_head *head, rcu_ca= llback_t func) { unsigned long flags; struct kfree_rcu_cpu *krcp; + void *ptr; =20 local_irq_save(flags); /* For safely calling this_cpu_ptr(). */ krcp =3D this_cpu_ptr(&krc); if (krcp->initialized) raw_spin_lock(&krcp->lock); =20 + ptr =3D (void *)head - (unsigned long)func; + /* Queue the object but don't yet schedule the batch. */ - if (debug_rcu_head_queue(head)) { + if (debug_rcu_head_queue(ptr)) { /* Probable double kfree_rcu(), just leak. */ WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n", __func__, head); --=20 2.20.1