From nobody Sun Feb 8 13:53:11 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB400C77B73 for ; Wed, 24 May 2023 10:02:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230107AbjEXKB7 (ORCPT ); Wed, 24 May 2023 06:01:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38504 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232020AbjEXKBn (ORCPT ); Wed, 24 May 2023 06:01:43 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA93312F; Wed, 24 May 2023 03:01:39 -0700 (PDT) Date: Wed, 24 May 2023 10:01:35 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1684922496; h=from:from:sender:sender:reply-to: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; bh=6FvvkhJf/VpDV2K3UEFi36r/TgLCYSuRfq0un7lMtc0=; b=Apcsf/ldQ3STJDYdOFw4txp9D9A5NgP6Tu5uaYIFrw05BacWvG/tNygtjIgSlxah5bPz5S Fs+Ggglat0z7o80EetmQkwkdGAX4cM6MkmPP769FqZuLPzCiCQl+0iyJGfqhWu4Vbgtjh+ pmyQ5M1sk1DFugUTKVYUp240V4pqd+g9NLy1UN83u62zRr8E1EXCw8i2mEiyGFJrj01Vhr 7jUveAHauKHgtFiuZLMlZx7B9ml8GTX3MlfWwdOhxB7rAqXMb2I8ONVszaW+rrCZcRKZI/ DVQWYxpyzvy4AdzHSpL/fX/vzqtrvB+vWj2Z2ECX+vaMhE9F1KPUztSGX9y4Vg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1684922496; h=from:from:sender:sender:reply-to: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; bh=6FvvkhJf/VpDV2K3UEFi36r/TgLCYSuRfq0un7lMtc0=; b=3QG3fcFPzMPy6K7+OGiGNu2KqawvhQ1XK9e6yzqUKRQepvqWefL23gwA60EMx9Ous4egUF eBKXoIh3ze15cHBw== From: "tip-bot2 for Shanker Donthineni" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: irq/core] genirq: Use a maple tree for interrupt descriptor management Cc: Shanker Donthineni , Thomas Gleixner , x86@kernel.org, linux-kernel@vger.kernel.org, maz@kernel.org In-Reply-To: <20230519134902.1495562-4-sdonthineni@nvidia.com> References: <20230519134902.1495562-4-sdonthineni@nvidia.com> MIME-Version: 1.0 Message-ID: <168492249583.404.6723379224465568533.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the irq/core branch of tip: Commit-ID: 721255b9826bd11c7a38b585905fc2dd0fb94e52 Gitweb: https://git.kernel.org/tip/721255b9826bd11c7a38b585905fc2dd0= fb94e52 Author: Shanker Donthineni AuthorDate: Fri, 19 May 2023 08:49:02 -05:00 Committer: Thomas Gleixner CommitterDate: Wed, 24 May 2023 11:39:44 +02:00 genirq: Use a maple tree for interrupt descriptor management The current implementation uses a static bitmap for interrupt descriptor allocation and a radix tree to pointer store the pointer for lookup. However, the size of the bitmap is constrained by the build time macro MAX_SPARSE_IRQS, which may not be sufficient to support high-end servers, particularly those with GICv4.1 hardware, which require a large interrupt space to cover LPIs and vSGIs. Replace the bitmap and the radix tree with a maple tree, which not only stores pointers for lookup, but also provides a mechanism to find free ranges. That removes the build time hardcoded upper limit. Signed-off-by: Shanker Donthineni Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230519134902.1495562-4-sdonthineni@nvidia= .com --- kernel/irq/internals.h | 2 +- kernel/irq/irqdesc.c | 57 +++++++++++++++++++++++------------------ 2 files changed, 33 insertions(+), 26 deletions(-) diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index f3f2090..7bdb750 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -12,7 +12,7 @@ #include =20 #ifdef CONFIG_SPARSE_IRQ -# define MAX_SPARSE_IRQS (NR_IRQS + 8196) +# define MAX_SPARSE_IRQS INT_MAX #else # define MAX_SPARSE_IRQS NR_IRQS #endif diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index e0d9dd9..27ca1c8 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -12,8 +12,7 @@ #include #include #include -#include -#include +#include #include #include =20 @@ -131,17 +130,39 @@ int nr_irqs =3D NR_IRQS; EXPORT_SYMBOL_GPL(nr_irqs); =20 static DEFINE_MUTEX(sparse_irq_lock); -static DECLARE_BITMAP(allocated_irqs, MAX_SPARSE_IRQS); +static struct maple_tree sparse_irqs =3D MTREE_INIT_EXT(sparse_irqs, + MT_FLAGS_ALLOC_RANGE | + MT_FLAGS_LOCK_EXTERN | + MT_FLAGS_USE_RCU, + sparse_irq_lock); =20 static int irq_find_free_area(unsigned int from, unsigned int cnt) { - return bitmap_find_next_zero_area(allocated_irqs, MAX_SPARSE_IRQS, - from, cnt, 0); + MA_STATE(mas, &sparse_irqs, 0, 0); + + if (mas_empty_area(&mas, from, MAX_SPARSE_IRQS, cnt)) + return -ENOSPC; + return mas.index; } =20 static unsigned int irq_find_at_or_after(unsigned int offset) { - return find_next_bit(allocated_irqs, nr_irqs, offset); + unsigned long index =3D offset; + struct irq_desc *desc =3D mt_find(&sparse_irqs, &index, nr_irqs); + + return desc ? irq_desc_get_irq(desc) : nr_irqs; +} + +static void irq_insert_desc(unsigned int irq, struct irq_desc *desc) +{ + MA_STATE(mas, &sparse_irqs, irq, irq); + WARN_ON(mas_store_gfp(&mas, desc, GFP_KERNEL) !=3D 0); +} + +static void delete_irq_desc(unsigned int irq) +{ + MA_STATE(mas, &sparse_irqs, irq, irq); + mas_erase(&mas); } =20 #ifdef CONFIG_SPARSE_IRQ @@ -355,26 +376,14 @@ static void irq_sysfs_del(struct irq_desc *desc) {} =20 #endif /* CONFIG_SYSFS */ =20 -static RADIX_TREE(irq_desc_tree, GFP_KERNEL); - -static void irq_insert_desc(unsigned int irq, struct irq_desc *desc) -{ - radix_tree_insert(&irq_desc_tree, irq, desc); -} - struct irq_desc *irq_to_desc(unsigned int irq) { - return radix_tree_lookup(&irq_desc_tree, irq); + return mtree_load(&sparse_irqs, irq); } #ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE EXPORT_SYMBOL_GPL(irq_to_desc); #endif =20 -static void delete_irq_desc(unsigned int irq) -{ - radix_tree_delete(&irq_desc_tree, irq); -} - #ifdef CONFIG_SMP static void free_masks(struct irq_desc *desc) { @@ -517,7 +526,6 @@ static int alloc_descs(unsigned int start, unsigned int= cnt, int node, irq_sysfs_add(start + i, desc); irq_add_debugfs_entry(start + i, desc); } - bitmap_set(allocated_irqs, start, cnt); return start; =20 err: @@ -557,7 +565,6 @@ int __init early_irq_init(void) =20 for (i =3D 0; i < initcnt; i++) { desc =3D alloc_desc(i, node, 0, NULL, NULL); - set_bit(i, allocated_irqs); irq_insert_desc(i, desc); } return arch_early_irq_init(); @@ -612,6 +619,7 @@ static void free_desc(unsigned int irq) raw_spin_lock_irqsave(&desc->lock, flags); desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL); raw_spin_unlock_irqrestore(&desc->lock, flags); + delete_irq_desc(irq); } =20 static inline int alloc_descs(unsigned int start, unsigned int cnt, int no= de, @@ -624,8 +632,8 @@ static inline int alloc_descs(unsigned int start, unsig= ned int cnt, int node, struct irq_desc *desc =3D irq_to_desc(start + i); =20 desc->owner =3D owner; + irq_insert_desc(start + i, desc); } - bitmap_set(allocated_irqs, start, cnt); return start; } =20 @@ -637,7 +645,7 @@ static int irq_expand_nr_irqs(unsigned int nr) void irq_mark_irq(unsigned int irq) { mutex_lock(&sparse_irq_lock); - bitmap_set(allocated_irqs, irq, 1); + irq_insert_desc(irq, irq_desc + irq); mutex_unlock(&sparse_irq_lock); } =20 @@ -781,7 +789,6 @@ void irq_free_descs(unsigned int from, unsigned int cnt) for (i =3D 0; i < cnt; i++) free_desc(from + i); =20 - bitmap_clear(allocated_irqs, from, cnt); mutex_unlock(&sparse_irq_lock); } EXPORT_SYMBOL_GPL(irq_free_descs); @@ -844,7 +851,7 @@ EXPORT_SYMBOL_GPL(__irq_alloc_descs); * irq_get_next_irq - get next allocated irq number * @offset: where to start the search * - * Returns next irq number at or after offset or nr_irqs if none is found. + * Returns next irq number after offset or nr_irqs if none is found. */ unsigned int irq_get_next_irq(unsigned int offset) {