From patchwork Sun Mar 16 04:05:35 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 14018292 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-wr1-f68.google.com (mail-wr1-f68.google.com [209.85.221.68]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2CF3D19DFAB; Sun, 16 Mar 2025 04:06:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.68 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742097972; cv=none; b=BsGts0xzn6TrZIKM4pnjkXmY7O8q0sY+suAAnd1zPFFPJhjB0evaRPyicM8ImNVr4tNN7n+iu8KDVBxG8D8cHrUW6PQdXxGq4gF5uYg1fSCDLxF3IqaZJ+/HtQDxEfeiGtZeoeFsIy2WxtDvzxJYFbzo/ghsues0T/xjya1Q07s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742097972; c=relaxed/simple; bh=VwAQAxwAow7TrrvxCboQzb6cYiUbz63qPyaMUR2Lneg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HlwkGzQ8oXW2Mesh3uawsmEuZqj8uTz54Y4SPLpxxhqfaAOaHwEyEwfLHX1xKI59TY4vXFfXjejm+6CCnDE1ucXk0nzUJUJ5r/Lanh+CcVtXCbjIJEqifTfZ5+mSOmgQ+0WTZmdZB5OzFUmYA+ddD4bbTNEJcqbvtnD+zU4wkEU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=fwo5xX6D; arc=none smtp.client-ip=209.85.221.68 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fwo5xX6D" Received: by mail-wr1-f68.google.com with SMTP id ffacd0b85a97d-39141ffa9fcso2847408f8f.0; Sat, 15 Mar 2025 21:06:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1742097968; x=1742702768; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=CF4Uk2MYBA/hkoA+QSy5dWTlz17aW/WlIb/dNVcZIBA=; b=fwo5xX6D5hc7ZOR1gA13/CIoA/m8pF3mnhd/Q3/FmmOri4qvbdJ8LYhhpz2tFnBQF6 iiBeGCxc9LwBzlWjpQHtJkY3d8fEkT6E5Bc/qQkasILJGj9V6BfRK8dE4njC88r1GcHR BIsB0zahnEcMsbucZPy3qJxUoRlSRzTur/U+G3LGcG6PmBXHN2eAUp4IOFB5Fj1dZPM1 sTFSctW3JgDW5NyG5FgWTrg1LkS8Xp2HYZsMBYz0XvkRGz6zof797WJAnw0zUlYhbX2g MYcrHnYM4aVEbUt9AYwaxM/rYyEho+Xit3hat8i3p3FctBdmx+FQvb3VTNoAE7NizkCC yvHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742097968; x=1742702768; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=CF4Uk2MYBA/hkoA+QSy5dWTlz17aW/WlIb/dNVcZIBA=; b=LYxByxq0EcboaUrG+hRpQBtz44GBeJuOahplEGqHCf74qSKVy+b4X2RcR+i68bZ25n M/CZJ7HYDRGBoNDoCZNj+iH01xsTIXbNVht/I8YUBdJNq2NeZ0eQoKhbU0Q3SIOwMUAB bq5HJ6jECjoRQiZtUM6WRkGYnrbM6NBeoLTs055VQQk+1D7Zlo1iVv4RlRVQKaWutF30 TJD2pnkjGNDD9o/YbJpPyA5Z/K93bYB0lSOvtJNxtNk9M9aFFCjm5MwMRxGnDUO/PkfG YVksqxIWz3sJ1dg1winjN0MpySTwB+u1clD0vXP8944fYU1stMDrOzFAm20tjZcBgNVk 9Hzw== X-Forwarded-Encrypted: i=1; AJvYcCV2NWh7ngZCX7wdKUSh2F6SlyjWXXqDTOPaTXwsRdf9ABgI5+j2HWkzzUxJRR2dko/tU6jpCAciXGhCGMU=@vger.kernel.org X-Gm-Message-State: AOJu0YzyHMAePD393kVjZ62cIbNrkb92ixAmoQtyV3o0I0X6k+woJ+Ri xQoIxZoanWDo3l3Mnh7l24c9zc8n/S6rDMyDC6PU6jKx/uaVMOHEH/uc+TWBsJM= X-Gm-Gg: ASbGncuzumG0JsLVgOQccg5l/9Cnln5SSh6mBq+aibbIuyjHgV9GfKvMdRBJTypYfOX 2AYeDbE27HZw3rCx1JXwtKOyrXCewfqk5UsbdZGQr/t8JI3HXWi4tvZsM0B3X5BwnSO70oEfHF+ Qrci75iLCrQIEPAwAJMasVXhn3fkOopYsW/25aQS+ZkUwFUzIq5d4KaiFN8RS9JVEASkb6QpEcV jmAdL03tSiYLH06xGNSknpADBhmkQ1G14T11PGLdbEt+GdHS5UlkHYNi8SwgAuq9U/6abZooiMZ B4ZwlSIo01epkRGE3nFbxaYDGlz3f0mkRUI= X-Google-Smtp-Source: AGHT+IG/cybe/X/vKmWywaeOPxKG+ExqzgfSAMkufyXQIte9dsBNmp17N0O0pQGVtXSWVe9+PQcBvQ== X-Received: by 2002:a5d:64a2:0:b0:38f:28dc:ec23 with SMTP id ffacd0b85a97d-3971d23799cmr10157067f8f.19.1742097967532; Sat, 15 Mar 2025 21:06:07 -0700 (PDT) Received: from localhost ([2a03:2880:31ff:48::]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-395cb7eb9d7sm10695515f8f.89.2025.03.15.21.06.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 15 Mar 2025 21:06:07 -0700 (PDT) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Linus Torvalds , Peter Zijlstra , Will Deacon , Waiman Long , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Eduard Zingerman , "Paul E. McKenney" , Tejun Heo , Barret Rhoden , Josh Don , Dohyun Kim , linux-arm-kernel@lists.infradead.org, kkd@meta.com, kernel-team@meta.com Subject: [PATCH bpf-next v4 19/25] bpf: Convert hashtab.c to rqspinlock Date: Sat, 15 Mar 2025 21:05:35 -0700 Message-ID: <20250316040541.108729-20-memxor@gmail.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250316040541.108729-1-memxor@gmail.com> References: <20250316040541.108729-1-memxor@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=11131; h=from:subject; bh=VwAQAxwAow7TrrvxCboQzb6cYiUbz63qPyaMUR2Lneg=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBn1k3eGs+bJjtEdeiJjw+Cd9PjBR7SOiQpae9Vzm/W Hk3IcQyJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCZ9ZN3gAKCRBM4MiGSL8RymFdD/ 4guFTOgG2ezQtX/qNWMi70RSbmgFndzWKODlNByC2n50hmYhhX9QlUKP+tsvZw793omMVa4G7ivzR8 dj195Z7rzAQlMEA+Y2fHGnBQqQWjPQhXQk2bQ1Mvvs4/C/zBpkrWLeXIrs3l4L0VhKDvg+nTGxmJGQ 5pe6Dz+d15FajBJ5NTRVGVX6/BLShHrT3NpUFLx1iGqGO6ilzcz0SKrJXuIX1thW1XMvRbyacIxc8d c4rraPbRxMyYAuYdgHX6O2iJCeDXsVnlCJ9w4YSuWCUoiRrt8AF+73hKjEtO7yhk59ZCUsvojBLWQ6 7OaL3u0YLBcxSyG4OsaCu27eyiDMBSYTJQVfjnq63hJ00wz+6TReX4DDpYAn/KUjeQLxVBgjJ2HRYh JMe4RZjVlfiK51f7sGm9Oy5JzPDbkpQSBBg9DDeMWd+aOkMDTzERynTnkWImFKroy/83XrcICnFQDC uSy6RpJt69kFqYBIjZ3E6vOhQOsNPO2Yrf53s+utbaMKhRLyMdMWYrgSiP2r0CSyFlpEWI3ZWhW9WF mfskIl0ctWP39nXAdkW/yj8vNd3DeBVAAoWJp35wU3L1cBjMrTAyXac4M8lv5Ua+lc7vYEe85mI1ry qx+it9Hd826i/HpocK9iaHfGwuWdtF0b2JNeAuwKceiyeIVeKMW5ebSgsc3w== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA X-Patchwork-Delegate: bpf@iogearbox.net Convert hashtab.c from raw_spinlock to rqspinlock, and drop the hashed per-cpu counter crud from the code base which is no longer necessary. Closes: https://lore.kernel.org/bpf/675302fd.050a0220.2477f.0004.GAE@google.com Closes: https://lore.kernel.org/bpf/000000000000b3e63e061eed3f6b@google.com Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/hashtab.c | 102 ++++++++++++++----------------------------- 1 file changed, 32 insertions(+), 70 deletions(-) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 877298133fda..5a5adc66b8e2 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -16,6 +16,7 @@ #include "bpf_lru_list.h" #include "map_in_map.h" #include +#include #define HTAB_CREATE_FLAG_MASK \ (BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE | \ @@ -78,7 +79,7 @@ */ struct bucket { struct hlist_nulls_head head; - raw_spinlock_t raw_lock; + rqspinlock_t raw_lock; }; #define HASHTAB_MAP_LOCK_COUNT 8 @@ -104,8 +105,6 @@ struct bpf_htab { u32 n_buckets; /* number of hash buckets */ u32 elem_size; /* size of each element in bytes */ u32 hashrnd; - struct lock_class_key lockdep_key; - int __percpu *map_locked[HASHTAB_MAP_LOCK_COUNT]; }; /* each htab element is struct htab_elem + key + value */ @@ -140,45 +139,26 @@ static void htab_init_buckets(struct bpf_htab *htab) for (i = 0; i < htab->n_buckets; i++) { INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i); - raw_spin_lock_init(&htab->buckets[i].raw_lock); - lockdep_set_class(&htab->buckets[i].raw_lock, - &htab->lockdep_key); + raw_res_spin_lock_init(&htab->buckets[i].raw_lock); cond_resched(); } } -static inline int htab_lock_bucket(const struct bpf_htab *htab, - struct bucket *b, u32 hash, - unsigned long *pflags) +static inline int htab_lock_bucket(struct bucket *b, unsigned long *pflags) { unsigned long flags; + int ret; - hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1); - - preempt_disable(); - local_irq_save(flags); - if (unlikely(__this_cpu_inc_return(*(htab->map_locked[hash])) != 1)) { - __this_cpu_dec(*(htab->map_locked[hash])); - local_irq_restore(flags); - preempt_enable(); - return -EBUSY; - } - - raw_spin_lock(&b->raw_lock); + ret = raw_res_spin_lock_irqsave(&b->raw_lock, flags); + if (ret) + return ret; *pflags = flags; - return 0; } -static inline void htab_unlock_bucket(const struct bpf_htab *htab, - struct bucket *b, u32 hash, - unsigned long flags) +static inline void htab_unlock_bucket(struct bucket *b, unsigned long flags) { - hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1); - raw_spin_unlock(&b->raw_lock); - __this_cpu_dec(*(htab->map_locked[hash])); - local_irq_restore(flags); - preempt_enable(); + raw_res_spin_unlock_irqrestore(&b->raw_lock, flags); } static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node); @@ -483,14 +463,12 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU); bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC); struct bpf_htab *htab; - int err, i; + int err; htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE); if (!htab) return ERR_PTR(-ENOMEM); - lockdep_register_key(&htab->lockdep_key); - bpf_map_init_from_attr(&htab->map, attr); if (percpu_lru) { @@ -536,15 +514,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) if (!htab->buckets) goto free_elem_count; - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) { - htab->map_locked[i] = bpf_map_alloc_percpu(&htab->map, - sizeof(int), - sizeof(int), - GFP_USER); - if (!htab->map_locked[i]) - goto free_map_locked; - } - if (htab->map.map_flags & BPF_F_ZERO_SEED) htab->hashrnd = 0; else @@ -607,15 +576,12 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) free_map_locked: if (htab->use_percpu_counter) percpu_counter_destroy(&htab->pcount); - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) - free_percpu(htab->map_locked[i]); bpf_map_area_free(htab->buckets); bpf_mem_alloc_destroy(&htab->pcpu_ma); bpf_mem_alloc_destroy(&htab->ma); free_elem_count: bpf_map_free_elem_count(&htab->map); free_htab: - lockdep_unregister_key(&htab->lockdep_key); bpf_map_area_free(htab); return ERR_PTR(err); } @@ -820,7 +786,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) b = __select_bucket(htab, tgt_l->hash); head = &b->head; - ret = htab_lock_bucket(htab, b, tgt_l->hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return false; @@ -831,7 +797,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) break; } - htab_unlock_bucket(htab, b, tgt_l->hash, flags); + htab_unlock_bucket(b, flags); if (l == tgt_l) check_and_free_fields(htab, l); @@ -1150,7 +1116,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, */ } - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return ret; @@ -1201,7 +1167,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, check_and_free_fields(htab, l_old); } } - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); if (l_old) { if (old_map_ptr) map->ops->map_fd_put_ptr(map, old_map_ptr, true); @@ -1210,7 +1176,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, } return 0; err: - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); return ret; } @@ -1257,7 +1223,7 @@ static long htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value copy_map_value(&htab->map, l_new->key + round_up(map->key_size, 8), value); - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) goto err_lock_bucket; @@ -1278,7 +1244,7 @@ static long htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value ret = 0; err: - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); err_lock_bucket: if (ret) @@ -1315,7 +1281,7 @@ static long __htab_percpu_map_update_elem(struct bpf_map *map, void *key, b = __select_bucket(htab, hash); head = &b->head; - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return ret; @@ -1340,7 +1306,7 @@ static long __htab_percpu_map_update_elem(struct bpf_map *map, void *key, } ret = 0; err: - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); return ret; } @@ -1381,7 +1347,7 @@ static long __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, return -ENOMEM; } - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) goto err_lock_bucket; @@ -1405,7 +1371,7 @@ static long __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, } ret = 0; err: - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); err_lock_bucket: if (l_new) { bpf_map_dec_elem_count(&htab->map); @@ -1447,7 +1413,7 @@ static long htab_map_delete_elem(struct bpf_map *map, void *key) b = __select_bucket(htab, hash); head = &b->head; - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return ret; @@ -1457,7 +1423,7 @@ static long htab_map_delete_elem(struct bpf_map *map, void *key) else ret = -ENOENT; - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); if (l) free_htab_elem(htab, l); @@ -1483,7 +1449,7 @@ static long htab_lru_map_delete_elem(struct bpf_map *map, void *key) b = __select_bucket(htab, hash); head = &b->head; - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return ret; @@ -1494,7 +1460,7 @@ static long htab_lru_map_delete_elem(struct bpf_map *map, void *key) else ret = -ENOENT; - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); if (l) htab_lru_push_free(htab, l); return ret; @@ -1561,7 +1527,6 @@ static void htab_map_free_timers_and_wq(struct bpf_map *map) static void htab_map_free(struct bpf_map *map) { struct bpf_htab *htab = container_of(map, struct bpf_htab, map); - int i; /* bpf_free_used_maps() or close(map_fd) will trigger this map_free callback. * bpf_free_used_maps() is called after bpf prog is no longer executing. @@ -1586,9 +1551,6 @@ static void htab_map_free(struct bpf_map *map) bpf_mem_alloc_destroy(&htab->ma); if (htab->use_percpu_counter) percpu_counter_destroy(&htab->pcount); - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) - free_percpu(htab->map_locked[i]); - lockdep_unregister_key(&htab->lockdep_key); bpf_map_area_free(htab); } @@ -1631,7 +1593,7 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key, b = __select_bucket(htab, hash); head = &b->head; - ret = htab_lock_bucket(htab, b, hash, &bflags); + ret = htab_lock_bucket(b, &bflags); if (ret) return ret; @@ -1668,7 +1630,7 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key, hlist_nulls_del_rcu(&l->hash_node); out_unlock: - htab_unlock_bucket(htab, b, hash, bflags); + htab_unlock_bucket(b, bflags); if (l) { if (is_lru_map) @@ -1790,7 +1752,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, head = &b->head; /* do not grab the lock unless need it (bucket_cnt > 0). */ if (locked) { - ret = htab_lock_bucket(htab, b, batch, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) { rcu_read_unlock(); bpf_enable_instrumentation(); @@ -1813,7 +1775,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, /* Note that since bucket_cnt > 0 here, it is implicit * that the locked was grabbed, so release it. */ - htab_unlock_bucket(htab, b, batch, flags); + htab_unlock_bucket(b, flags); rcu_read_unlock(); bpf_enable_instrumentation(); goto after_loop; @@ -1824,7 +1786,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, /* Note that since bucket_cnt > 0 here, it is implicit * that the locked was grabbed, so release it. */ - htab_unlock_bucket(htab, b, batch, flags); + htab_unlock_bucket(b, flags); rcu_read_unlock(); bpf_enable_instrumentation(); kvfree(keys); @@ -1887,7 +1849,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, dst_val += value_size; } - htab_unlock_bucket(htab, b, batch, flags); + htab_unlock_bucket(b, flags); locked = false; while (node_to_free) {