From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f179.google.com (mail-pf1-f179.google.com [209.85.210.179]) (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 0C0C731A800 for ; Wed, 26 Nov 2025 08:50:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764147034; cv=none; b=fU2CycdudE0tXlVdidPgz3+MB9WdWpNRStaN43zhgJTFz6T59uKi4klvkZIwIQ7oofhlHBQB+PLbqrSB8zMKEYpflJLlXdoAxD8PgkWG4nhVW1NliHdPUGg8CfK2WY9+aq8sPqkrRCPTCNBgOfB8kd8GByBtO2LgRGdJJFJIZHI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764147034; c=relaxed/simple; bh=evRz1+RSm19y+i3oY7bdpBtGC57ReMDJiKJsw3sQlM0=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=N9XLZDWXn692nOyKumt6QS3q2377ydtaXnGnRKm6d1DzJ7B+3ehQljOEryzvE+llMPcd/RLQCPFP2CKMEvfqJ7Vwooh4XbllCc8eY+8F7kr9ZVvyyhLUsLzVuQ4X2kTkimW/t5O646W/IsCoXhEKFe7AXgm0DcdzZR8gv1q+OdU= 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=dbyaEBvs; arc=none smtp.client-ip=209.85.210.179 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="dbyaEBvs" Received: by mail-pf1-f179.google.com with SMTP id d2e1a72fcca58-7a9cdf62d31so7754802b3a.3 for ; Wed, 26 Nov 2025 00:50:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1764147032; x=1764751832; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=BxNPd6xRith5Tmbdr3Wot2eK29BxDgV+As0Pvo83p7s=; b=dbyaEBvs9sQs4p4BAcalyfiJRwv+fJo6/Byitwms7jvG8lph03fptcGSv7+hS/mmV1 7Z6VSwOZTQXCWpANavbHtuVeoQJq3QgKwFYO+76ychExOvj5l55znoeVLbYcFgbVpL7H mR8SPxCfZk5EaaphpB1eH5YNtEvI/ZayjhNmfoCtM5fbej0juHa3wb6QQy5l1edupGIf kdpBNVyZCPAsl+/OD8+G6kD2peu82YukJouN+WpNmdQvd1Z6TZGxSqWishhoY884hXIp ypXH81TNXTTfyEnSmj8GTGINUrXCQFj/3s6RV6zeP+RaenTiV84uERhZQCkntEE42r+k 26eA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764147032; x=1764751832; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=BxNPd6xRith5Tmbdr3Wot2eK29BxDgV+As0Pvo83p7s=; b=fjZc3cv6WpX1HT/pe54hyXwMJ73OVNnS4/0I134fc5exj72VCNd4NEHY18y92H4UQM uOVaNExnlpVm2bd0H7oUUDqyZH0WZikxc8JQ6haZms/q0caVbndgmNSs9WGmO28cASat Sz6tx3AkeakOW52hUnIEHsjhaFgYHm9hbdTPua34Z2vTXgAUQg21nbIXFWcs+rRLWsZy 5HjdrOGCXBPcCjbI/DeJXAqtUSRWi9NUX9PU5MKiI7/kgZwvEKHepkM5O2NZwumIPwHH AJc9RY8S4lCTckg7JnG125ZWQOQwtkU6yJUqA+QfSBh6iRYG1V8w3g2o5BmgjmrxS6VJ vcIg== X-Forwarded-Encrypted: i=1; AJvYcCX0smxTqdfaihumya4exLW51RLGC17P46daugjbitcPezQGpkUz9GSPW2qlOEdJ6AMsUpRh9l2r9Pcwn2s=@vger.kernel.org X-Gm-Message-State: AOJu0YziXcA4yb58+6IMBRkXvbE07BWmq1KM/ZOkcaUUwkeJHp4JBT27 WXFx1AuZxt1LUcsNtQC7Hq2yXKJl5hKa6iiPW8dOv5OXVlhSifcfCKDM X-Gm-Gg: ASbGncsBwMG/PxbK0sfTCRvn71ahXEggNJ33uARzBA1MM35qE3z0sKJlcoBsZmgZvA4 3zcDamiXiVTE7vV0Kx3Q2DuzT19Gd7po7LYRWb+XYlxqJqbmz12CEHYUShaMqyLAy34rych1U+r i7mjDnp9vK5MrNM1eOYvmupLTcyp4zWLxYaDXks+OcIfprOYIrnwZxM+/99i9dIM8e+635SJFHB O2CssfHscPPnpI7VHIpfyve0EdW/oygMVSHLbAQK8/KMOvzyWK0gGOS3snVT2bz4ZU1dFdfr/m6 rf2VBdiFMK5Ft+pj4l7B/9rDEapCDF+p/hl7t3ZfrpNArMAiiTDXF6l5fhS41/UPiuG96CWq65c ZTbtOGAUG76CpjDb2eNlpdm/4l65SjfZa6lxFZo3rxzOZpr+REcck8JEDEA2TmfpZXOoDP2p7bl owOa+vlOdAojrEdF2WxMxZfkOpBa0= X-Google-Smtp-Source: AGHT+IGwLyfOcKohWhkx4wsLXmUqJy8CxtZzVuBRUWq8FkbjIG+P5Po6itxt7NmRJiyuHIpiKAEfBw== X-Received: by 2002:a05:6a00:10c6:b0:7aa:d1d4:bb68 with SMTP id d2e1a72fcca58-7c58e112cb4mr17344571b3a.20.1764147032313; Wed, 26 Nov 2025 00:50:32 -0800 (PST) Received: from pengdl-pc.mioffice.cn ([43.224.245.249]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7c3f023fd82sm20885721b3a.42.2025.11.26.00.50.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Nov 2025 00:50:31 -0800 (PST) From: Donglin Peng To: ast@kernel.org, andrii.nakryiko@gmail.com Cc: eddyz87@gmail.com, zhangxiaoqin@xiaomi.com, ihor.solodrai@linux.dev, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, pengdonglin Subject: [RFC bpf-next v8 0/9] Improve the performance of BTF type lookups with binary search Date: Wed, 26 Nov 2025 16:50:16 +0800 Message-Id: <20251126085025.784288-1-dolinux.peng@gmail.com> X-Mailer: git-send-email 2.34.1 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 This patch series introduces significant performance improvements (~2855x) for BTF type lookups by implementing type permutation and binary search optimizations. The series addresses the performance limitations of linear search in large BTFs by: 1. Adding BTF permutation support 2. Using resolve_btfids to sort BTF during the build phase 3. Checking BTF sorting 4. Using binary search when looking up types Patch #1 introduces an interface for btf__permute in libbpf to relay out BTF. Patch #2 adds test cases to validate the functionality of btf__permute in base and split BTF scenarios. Patch #3 introduces a new phase in the resolve_btfids tool to sort BTF by name in ascending order. Patches #4-#7 implement the sorting check and binary search. Patches #8-#9 optimize type lookup performance of two kernel functions. Here is a simple performance result [1] to find 60,995 named types in vmlinux BTF: ./vmtest.sh -- ./test_progs -t btf_permute/perf -v Results: | Condition | Lookup Time | Improvement | |--------------------|-------------|--------------| | Unsorted (Linear) | 27,697.4 ms | Baseline | | Sorted (Binary) | 9.7 ms | 2855x faster | The binary search implementation reduces lookup time from 27.7 seconds to 9.7 milliseconds, achieving a **2855x** speedup for large-scale type queries. Changelog: v8: - Remove the type dropping feature of btf__permute (Andrii) - Refactor the code of btf__permute (Andrii, Eduard) - Make the self-test code cleaner (Eduard) - Reconstruct the BTF sorting patch based on Ihor's patch series [2] - Simplify the sorting logic and place anonymous types before named types (Andrii, Eduard) - Optimize type lookup performance of two kernel functions - Refactoring the binary search and type lookup logic achieves a 4.2% performance gain, reducing the average lookup time (via the perf test code in [1] for 60,995 named types in vmlinux BTF) from 10,217 us (v7) to 9,783 us (v8). v7: - Link: https://lore.kernel.org/all/20251119031531.1817099-1-dolinux.peng@gmail.com/ - btf__permute API refinement: Adjusted id_map and id_map_cnt parameter usage so that for base BTF, id_map[0] now contains the new id of original type id 1 (instead of VOID type id 0), improving logical consistency - Selftest updates: Modified test cases to align with the API usage changes - Refactor the code of resolve_btfids v6: - Link: https://lore.kernel.org/all/20251117132623.3807094-1-dolinux.peng@gmail.com/ - ID Map-based reimplementation of btf__permute (Andrii) - Build-time BTF sorting using resolve_btfids (Alexei, Eduard) - Binary search method refactoring (Andrii) - Enhanced selftest coverage v5: - Link: https://lore.kernel.org/all/20251106131956.1222864-1-dolinux.peng@gmail.com/ - Refactor binary search implementation for improved efficiency (Thanks to Andrii and Eduard) - Extend btf__permute interface with 'ids_sz' parameter to support type dropping feature (suggested by Andrii). Plan subsequent reimplementation of id_map version for comparative analysis with current sequence interface - Add comprehensive test coverage for type dropping functionality - Enhance function comment clarity and accuracy v4: - Link: https://lore.kernel.org/all/20251104134033.344807-1-dolinux.peng@gmail.com/ - Abstracted btf_dedup_remap_types logic into a helper function (suggested by Eduard). - Removed btf_sort.c and implemented sorting separately for libbpf and kernel (suggested by Andrii). - Added test cases for both base BTF and split BTF scenarios (suggested by Eduard). - Added validation for name-only sorting of types (suggested by Andrii) - Refactored btf__permute implementation to reduce complexity (suggested by Andrii) - Add doc comments for btf__permute (suggested by Andrii) v3: - Link: https://lore.kernel.org/all/20251027135423.3098490-1-dolinux.peng@gmail.com/ - Remove sorting logic from libbpf and provide a generic btf__permute() interface (suggested by Andrii) - Omitted the search direction patch to avoid conflicts with base BTF (suggested by Eduard). - Include btf_sort.c directly in btf.c to reduce function call overhead v2: - Link: https://lore.kernel.org/all/20251020093941.548058-1-dolinux.peng@gmail.com/ - Moved sorting to the build phase to reduce overhead (suggested by Alexei). - Integrated sorting into btf_dedup_compact_and_sort_types (suggested by Eduard). - Added sorting checks during BTF parsing. - Consolidated common logic into btf_sort.c for sharing (suggested by Alan). v1: - Link: https://lore.kernel.org/all/20251013131537.1927035-1-dolinux.peng@gmail.com/ [1] https://github.com/pengdonglin137/btf_sort_test [2] https://lore.kernel.org/bpf/20251126012656.3546071-1-ihor.solodrai@linux.dev/ pengdonglin (9): libbpf: Add BTF permutation support for type reordering selftests/bpf: Add test cases for btf__permute functionality tools/resolve_btfids: Support BTF sorting feature libbpf: Optimize type lookup with binary search for sorted BTF libbpf: Verify BTF Sorting btf: Optimize type lookup with binary search btf: Verify BTF Sorting bpf: Optimize the performance of find_btf_percpu_datasec bpf: Optimize the performance of find_bpffs_btf_enums include/linux/btf.h | 1 + kernel/bpf/btf.c | 148 +++++++++- kernel/bpf/inode.c | 42 ++- kernel/bpf/verifier.c | 7 +- tools/bpf/resolve_btfids/main.c | 68 +++++ tools/lib/bpf/btf.c | 260 ++++++++++++++++-- tools/lib/bpf/btf.h | 36 +++ tools/lib/bpf/libbpf.map | 1 + .../selftests/bpf/prog_tests/btf_permute.c | 228 +++++++++++++++ 9 files changed, 733 insertions(+), 58 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/btf_permute.c -- 2.34.1