From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f44.google.com (mail-pj1-f44.google.com [209.85.216.44]) (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 B0A47329E5F for ; Tue, 4 Nov 2025 13:40:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762263660; cv=none; b=ZhvZeywIIe3Te1LrS7a1i154KHFAGXpgXI5mXQkfCZfhzKxHpI+PyD7AWgksNes0olLuPhNlF7adJxGIHrtCLbOMDKXfwnGV/LIpourAUvJxlXFvJrHIBckcC6EiQCVy7fdiBmb9B/L4jhL5WJN7Cp79TLOiWBfkRwAX5sYuOYM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762263660; c=relaxed/simple; bh=O6TUJSSCk6Hrp9bJcJkRtQGi3MrZ6klrSIFDZ+Yqcj0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=nKHYaeY3Gnd565tof1gKukN+TLoNN6bnnrEUzc5QKwj3OQ/0D444HFaQNgPGSpOWFTXouLuHHphFSAsCYk7lDUlq/vt5BYU86t/tXl/bM4ex+yysD2Mrh4zC5EoVbHXGDK7ObSNL1SwymH7/abYH+JTjwfHFeoG/J1uhd0ht1fo= 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=dsyeWg5v; arc=none smtp.client-ip=209.85.216.44 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="dsyeWg5v" Received: by mail-pj1-f44.google.com with SMTP id 98e67ed59e1d1-340c680fe8cso2742104a91.0 for ; Tue, 04 Nov 2025 05:40:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1762263658; x=1762868458; 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=jdH6dhdE/ct/5KpUEPIcc/WirZeO6VXg0US4f0SIffI=; b=dsyeWg5vESLqY1C4wf6DCQ7X2SnLnEJarGtvpuW90ZzO9DvG6Gb+dGTHcST3+aukXE mbrZHcutLkA2PMAfTDtWQqsRakc2aMA0XzofDw8I2plGkOQcVeRBrG4xrTG7nIuP6S+T vOfZMs2+e6vwaNowi/sJm6o5Tr9zqZm7npGtxFnMqrEFuDrMGuFYEuAgaiWlx/XvzTDO vw+SgTk9d+wxyP7VVWaSG8G7+TzsczYjBShbLvHyPt8QV+7M3c/Y9oPnL6oHyqmIeioM 9GLyqQP4rPlwGgvgX1bluEQCL5632H8JPuXHeQY7He3K4c1GNk1yoenByUVSObwAxSiB 1S4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762263658; x=1762868458; 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=jdH6dhdE/ct/5KpUEPIcc/WirZeO6VXg0US4f0SIffI=; b=cBGOaKbDyqIdNad47rppCkQXRRkRbZALNpIEjO+gjP2zpn8aTuC+Zcr2xgbaLaAbhi w27ahgC1XpbVWenMnIzY6w/mATN6EzRMTbUK8+HEPoiQWCXjFItsmrP8h4+4DYjGXtdT Sybi21/IYm0eHj2GAG4OUrTd4HYBky5IiCGx9rfV4u6fGwfNJ7ICL4JOTgqS82qj9+6r 7p2uEN4INFYyayUtdqtyyvRq7PFKTsl51cjptBwSpTn/Z6FUAHjWmf+yLb7KfOM7og8h EAkQlsac87w+u9y7Nkv2ZBsHWFF/l41neI6F925LAJWIqMcETMWmimtDCaEw+/Bpcm8G Qf+g== X-Gm-Message-State: AOJu0YyUJWCQOx4PSRROW5KY93XAmUX0fqRyfr1Mu1RXkCMd13OKmikf a5ETjPfD2tIBMuqqe2QmbVF5yGYYVba+ERCxKX4MuO7s+T21JvU5ca+E X-Gm-Gg: ASbGncuK5PORowMlPJoBMC0XZZipMaOYEVgJmz0l70oo7w3WrBnq6VLUVEqF3YPK24m 9CaUkf4Mre74dwyfdmqbYwki860gE29WTKJzh+biCbT/SvSMAPaaiIunLZ1UWyx5aqqcjm0HOpq HNtrylkfpP5yLjQLQf0uLxpRIQhBfDRrFdxAkkHBNQ+KvMRH6VoNzo8kY/8eLUuQ8Nf3VpYoaie Lr4mX0MXWcPQsU8U3Zjl+CgY3n+TgZv7vaLAJ64kQoqFL50ScRAwspwHNzRBahOHPprkaqx8pac iHnI/vP6BMG9dfZW7AAS2OuUaFIHD++lqN9zHg2iF8ceVdiYc4lTfHBYHAkFO/M6rJT+T2i+n/T Mje3l49ivT2M96SQFmdfxqBx5mQfiA5AouYpHCX5g6UA9oRJ7yuUR67x1mRS1kxtyjxhRrIIxpq kaTAe/u//QwqKbNN1+ X-Google-Smtp-Source: AGHT+IG4CexyTG0Va7f3enA8yUQx0oRFu4DeDd1sF7PSgO2tkGhxl3YEWxrzB4hWgbdaNFwN/l7fMw== X-Received: by 2002:a17:90b:5104:b0:341:88c9:6eb2 with SMTP id 98e67ed59e1d1-34188c96eb7mr1911737a91.1.1762263658014; Tue, 04 Nov 2025 05:40:58 -0800 (PST) Received: from pengdl-pc.mioffice.cn ([43.224.245.249]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-ba1f87a7287sm2499238a12.31.2025.11.04.05.40.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Nov 2025 05:40:56 -0800 (PST) From: Donglin Peng To: ast@kernel.org Cc: linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Donglin Peng , Eduard Zingerman , Andrii Nakryiko , Alan Maguire , Song Liu , pengdonglin Subject: [RFC PATCH v4 5/7] btf: Optimize type lookup with binary search Date: Tue, 4 Nov 2025 21:40:31 +0800 Message-Id: <20251104134033.344807-6-dolinux.peng@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251104134033.344807-1-dolinux.peng@gmail.com> References: <20251104134033.344807-1-dolinux.peng@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: pengdonglin Improve btf_find_by_name_kind() performance by adding binary search support for sorted types. Falls back to linear search for compatibility. Cc: Eduard Zingerman Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Alan Maguire Cc: Song Liu Signed-off-by: pengdonglin Signed-off-by: Donglin Peng --- kernel/bpf/btf.c | 111 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 101 insertions(+), 10 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 0de8fc8a0e0b..da35d8636b9b 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -259,6 +259,7 @@ struct btf { void *nohdr_data; struct btf_header hdr; u32 nr_types; /* includes VOID for base BTF */ + u32 nr_sorted_types; /* exclude VOID for base BTF */ u32 types_size; u32 data_size; refcount_t refcnt; @@ -494,6 +495,11 @@ static bool btf_type_is_modifier(const struct btf_type *t) return false; } +static int btf_start_id(const struct btf *btf) +{ + return btf->start_id + (btf->base_btf ? 0 : 1); +} + bool btf_type_is_void(const struct btf_type *t) { return t == &btf_void; @@ -544,24 +550,109 @@ u32 btf_nr_types(const struct btf *btf) return total; } -s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) +/* Find BTF types with matching names within the [left, right] index range. + * On success, updates *left and *right to the boundaries of the matching range + * and returns the leftmost matching index. + */ +static s32 btf_find_by_name_kind_bsearch(const struct btf *btf, const char *name, + s32 *left, s32 *right) { const struct btf_type *t; const char *tname; - u32 i, total; + s32 l, r, m, lmost, rmost; + int ret; - total = btf_nr_types(btf); - for (i = 1; i < total; i++) { - t = btf_type_by_id(btf, i); - if (BTF_INFO_KIND(t->info) != kind) - continue; + /* found the leftmost btf_type that matches */ + l = *left; + r = *right; + lmost = -1; + while (l <= r) { + m = l + (r - l) / 2; + t = btf_type_by_id(btf, m); + tname = btf_name_by_offset(btf, t->name_off); + ret = strcmp(tname, name); + if (ret < 0) { + l = m + 1; + } else { + if (ret == 0) + lmost = m; + r = m - 1; + } + } + if (lmost == -1) + return -ENOENT; + + /* found the rightmost btf_type that matches */ + l = lmost; + r = *right; + rmost = -1; + while (l <= r) { + m = l + (r - l) / 2; + t = btf_type_by_id(btf, m); tname = btf_name_by_offset(btf, t->name_off); - if (!strcmp(tname, name)) - return i; + ret = strcmp(tname, name); + if (ret <= 0) { + if (ret == 0) + rmost = m; + l = m + 1; + } else { + r = m - 1; + } } - return -ENOENT; + *left = lmost; + *right = rmost; + return lmost; +} + +s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) +{ + const struct btf *base_btf = btf_base_btf(btf);; + const struct btf_type *t; + const char *tname; + int err = -ENOENT; + + if (base_btf) + err = btf_find_by_name_kind(base_btf, name, kind); + + if (err == -ENOENT) { + if (btf->nr_sorted_types) { + /* binary search */ + s32 l, r; + int ret; + + l = btf_start_id(btf); + r = l + btf->nr_sorted_types - 1; + ret = btf_find_by_name_kind_bsearch(btf, name, &l, &r); + if (ret < 0) + goto out; + /* found the leftmost btf_type that matches */ + while (l <= r) { + t = btf_type_by_id(btf, l); + if (BTF_INFO_KIND(t->info) == kind) + return l; + l++; + } + } else { + /* linear search */ + u32 i, total; + + total = btf_nr_types(btf); + for (i = btf_start_id(btf); i < total; i++) { + t = btf_type_by_id(btf, i); + if (BTF_INFO_KIND(t->info) != kind) + continue; + + tname = btf_name_by_offset(btf, t->name_off); + if (!strcmp(tname, name)) + return i; + } + } + } + +out: + return err; } s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) -- 2.34.1