From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by sourceware.org (Postfix) with ESMTPS id E860C3858C31 for ; Wed, 6 Dec 2023 17:07:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org E860C3858C31 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=rivosinc.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org E860C3858C31 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::1032 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701882484; cv=none; b=Hq1V1GYK9IOp0eHAA5RLX8x69uWMP7N75eD/U0qpRVETV3l9QHikNHbljiGqx37L6gPhUvlZ/RajtMnzZaSPyyUm33znlNx/kOLzKkx+Iargyp+pr/rOAe6awaB9ZBktgLyR2Av138TpBQ99pFORcV3Bu57yl/mCgtHnEu9eTg8= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701882484; c=relaxed/simple; bh=OZKHVailON9K9wljULNRAXyvbXI0sWF5dUxYs7+GFGA=; h=DKIM-Signature:Date:Subject:From:To:Message-ID:Mime-Version; b=bsb/94IB4Cp7Y+mSy12rb/aQQOgDFZ9/mfy+B1rtg0vrFQnWSltrgDMiO/K8piM3mcc6Y2jYE5/Yq+M3063iKc4+fJD/08Cz3H1jSc8+4PkRc7SkPNr5szL6znHnCuykQmQOboKGILxrFjC7Ih6EweBe8h2Cv5r5HOpuSF1bEPA= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-pj1-x1032.google.com with SMTP id 98e67ed59e1d1-28694702c18so32652a91.3 for ; Wed, 06 Dec 2023 09:07:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1701882471; x=1702487271; darn=sourceware.org; h=content-transfer-encoding:mime-version:message-id:to:from:cc :in-reply-to:subject:date:from:to:cc:subject:date:message-id :reply-to; bh=k5k42d/wlwmtBvvWq9np1zH5Db6hH+ArpZp1u+zKBEY=; b=QkhKSBkFdnM9ZL9JaMbg0ohH5vXVQflOXDWZMo8UBiKqdM7DLB+d4P/KeFQ6Qb+opK ZLbz6SEPBpz9VD6HbrDhVfZMNdt4MCTKCkWMl/ty3x3Y040yneQMSh/qYVuW0gifd3sr tFtKGhVkdl3TS0wtRlHCKT5RzYLz8RyzeLCZQ5L1VO6FtTdxH/KDaI23qneAgXjBKhuL Qp4ou3weyOrRk1o2gb0qzTZHyqNqFSM2Icd36VyGOVtjLR2vFRUTLX6Bz3dBECQ7e1wz OcLn8VAr5FCVJvNJsv5yJIIfQzBZZ0VRiHpUGnmBFw3GDyDWukRn2P++1b7ryjPbQBvt bW0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701882471; x=1702487271; h=content-transfer-encoding:mime-version:message-id:to:from:cc :in-reply-to:subject:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=k5k42d/wlwmtBvvWq9np1zH5Db6hH+ArpZp1u+zKBEY=; b=W4vj4OKx/6Bu9Wyj7hf14wfDmBeZux7mlshtKrLZnpXCovlRhnnnDP2+dMSrf93cVo Yv1qDL0tflyEFfOQaSNeRi5Bn9ysRL8ztlEfQ8LZjsEUbMhJ/VGAe2MnwrbxiWGQxVwe PU0roGUhE0UJjaUcS63sjQD0wJ5qXB9hWRIeXKNwZI1Tpo6F5UkpuuRoWdoyHVr8Iwpo LxQW0wZYjydhLQTxVHC1T9LVARlKsiqU1ioRkW+7asU8h6LQVd45fZhSHqoFbHd+HK2I l74vb9Bv3PJtqaD43u5meggSs4AEH9gaxTsM7nzCyArFtBQgfwVtXtkeWTDm+/v8iWNK IYSg== X-Gm-Message-State: AOJu0Yyt38ANxTXOYiuRGdl5iZZCQRRWQ5Qm1DWeXP0Ez8btw9quAHzn jtWA35y9txx8MglGnVPg/yORRMfBlwA3ME3fWyc= X-Google-Smtp-Source: AGHT+IGx0H2gcowMLunutggw99yNRxIczZDivazb27QfwsEH5putImqOv3pjWQstapoZQ65AgWIGSQ== X-Received: by 2002:a17:90a:1957:b0:286:6cc0:cae6 with SMTP id 23-20020a17090a195700b002866cc0cae6mr1106884pjh.93.1701882471504; Wed, 06 Dec 2023 09:07:51 -0800 (PST) Received: from localhost ([192.184.165.199]) by smtp.gmail.com with ESMTPSA id g8-20020a17090a9b8800b002853349e490sm103775pjp.34.2023.12.06.09.07.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Dec 2023 09:07:50 -0800 (PST) Date: Wed, 06 Dec 2023 09:07:50 -0800 (PST) X-Google-Original-Date: Wed, 06 Dec 2023 08:59:48 PST (-0800) Subject: Re: [PATCH v9 0/6] RISC-V: ifunced memcpy using new kernel hwprobe interface In-Reply-To: <20231130183239.598100-1-evan@rivosinc.com> CC: libc-alpha@sourceware.org, fweimer@redhat.com, Vineet Gupta , slewis@rivosinc.com, Evan Green From: Palmer Dabbelt To: Evan Green Message-ID: Mime-Version: 1.0 (MHng) Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Thu, 30 Nov 2023 10:32:33 PST (-0800), Evan Green wrote: > > This series illustrates the use of a recently accepted Linux syscall that > enumerates architectural information about the RISC-V cores the system > is running on. In this series we expose a small wrapper function around > the syscall. An ifunc selector for memcpy queries it to see if unaligned > access is "fast" on this hardware. If it is, it selects a newly provided > implementation of memcpy that doesn't work hard at aligning the src and > destination buffers. > > For applications and libraries outside of glibc that want to use > __riscv_hwprobe() in ifunc selectors, this series also sends a pointer > to the riscv_hwprobe() function in as the second argument to ifunc > selectors. A new inline convenience function can help application and > library callers to check for validity and quickly probe a single key. > > The memcpy implementation is independent enough from the rest of the > series that it can be omitted safely if desired. > > Performance numbers were compared using a small test program [1], run on > a D1 Nezha board, which supports fast unaligned access. "Fast" here > means copying unaligned words is faster than copying byte-wise, but > still slower than copying aligned words. Here's the speed of various > memcpy()s with the generic implementation. The numbers before are using > v4's memcpy implementation, with the "copy last byte via overlapping > misaligned word" fix this should get slightly better. > > memcpy size 1 count 1000000 offset 0 took 109564 us > memcpy size 3 count 1000000 offset 0 took 138425 us > memcpy size 4 count 1000000 offset 0 took 148374 us > memcpy size 7 count 1000000 offset 0 took 178433 us > memcpy size 8 count 1000000 offset 0 took 188430 us > memcpy size f count 1000000 offset 0 took 266118 us > memcpy size f count 1000000 offset 1 took 265940 us > memcpy size f count 1000000 offset 3 took 265934 us > memcpy size f count 1000000 offset 7 took 266215 us > memcpy size f count 1000000 offset 8 took 265954 us > memcpy size f count 1000000 offset 9 took 265886 us > memcpy size 10 count 1000000 offset 0 took 195308 us > memcpy size 11 count 1000000 offset 0 took 205161 us > memcpy size 17 count 1000000 offset 0 took 274376 us > memcpy size 18 count 1000000 offset 0 took 199188 us > memcpy size 19 count 1000000 offset 0 took 209258 us > memcpy size 1f count 1000000 offset 0 took 278263 us > memcpy size 20 count 1000000 offset 0 took 207364 us > memcpy size 21 count 1000000 offset 0 took 217143 us > memcpy size 3f count 1000000 offset 0 took 300023 us > memcpy size 40 count 1000000 offset 0 took 231063 us > memcpy size 41 count 1000000 offset 0 took 241259 us > memcpy size 7c count 100000 offset 0 took 32807 us > memcpy size 7f count 100000 offset 0 took 36274 us > memcpy size ff count 100000 offset 0 took 47818 us > memcpy size ff count 100000 offset 0 took 47932 us > memcpy size 100 count 100000 offset 0 took 40468 us > memcpy size 200 count 100000 offset 0 took 64245 us > memcpy size 27f count 100000 offset 0 took 82549 us > memcpy size 400 count 100000 offset 0 took 111254 us > memcpy size 407 count 100000 offset 0 took 119364 us > memcpy size 800 count 100000 offset 0 took 203899 us > memcpy size 87f count 100000 offset 0 took 222465 us > memcpy size 87f count 100000 offset 3 took 222289 us > memcpy size 1000 count 100000 offset 0 took 388846 us > memcpy size 1000 count 100000 offset 1 took 468827 us > memcpy size 1000 count 100000 offset 3 took 397098 us > memcpy size 1000 count 100000 offset 4 took 397379 us > memcpy size 1000 count 100000 offset 5 took 397368 us > memcpy size 1000 count 100000 offset 7 took 396867 us > memcpy size 1000 count 100000 offset 8 took 389227 us > memcpy size 1000 count 100000 offset 9 took 395949 us > memcpy size 3000 count 50000 offset 0 took 674837 us > memcpy size 3000 count 50000 offset 1 took 676944 us > memcpy size 3000 count 50000 offset 3 took 679709 us > memcpy size 3000 count 50000 offset 4 took 680829 us > memcpy size 3000 count 50000 offset 5 took 678024 us > memcpy size 3000 count 50000 offset 7 took 681097 us > memcpy size 3000 count 50000 offset 8 took 670004 us > memcpy size 3000 count 50000 offset 9 took 674553 us > > Here is that same test run with the assembly memcpy() in this series: > memcpy size 1 count 1000000 offset 0 took 92703 us > memcpy size 3 count 1000000 offset 0 took 112527 us > memcpy size 4 count 1000000 offset 0 took 120481 us > memcpy size 7 count 1000000 offset 0 took 149558 us > memcpy size 8 count 1000000 offset 0 took 90617 us > memcpy size f count 1000000 offset 0 took 174373 us > memcpy size f count 1000000 offset 1 took 178615 us > memcpy size f count 1000000 offset 3 took 178845 us > memcpy size f count 1000000 offset 7 took 178636 us > memcpy size f count 1000000 offset 8 took 174442 us > memcpy size f count 1000000 offset 9 took 178660 us > memcpy size 10 count 1000000 offset 0 took 99845 us > memcpy size 11 count 1000000 offset 0 took 112522 us > memcpy size 17 count 1000000 offset 0 took 179735 us > memcpy size 18 count 1000000 offset 0 took 110870 us > memcpy size 19 count 1000000 offset 0 took 121472 us > memcpy size 1f count 1000000 offset 0 took 188231 us > memcpy size 20 count 1000000 offset 0 took 119571 us > memcpy size 21 count 1000000 offset 0 took 132429 us > memcpy size 3f count 1000000 offset 0 took 227021 us > memcpy size 40 count 1000000 offset 0 took 166416 us > memcpy size 41 count 1000000 offset 0 took 180206 us > memcpy size 7c count 100000 offset 0 took 28602 us > memcpy size 7f count 100000 offset 0 took 31676 us > memcpy size ff count 100000 offset 0 took 39257 us > memcpy size ff count 100000 offset 0 took 39176 us > memcpy size 100 count 100000 offset 0 took 21928 us > memcpy size 200 count 100000 offset 0 took 35814 us > memcpy size 27f count 100000 offset 0 took 60315 us > memcpy size 400 count 100000 offset 0 took 63652 us > memcpy size 407 count 100000 offset 0 took 73160 us > memcpy size 800 count 100000 offset 0 took 121532 us > memcpy size 87f count 100000 offset 0 took 147269 us > memcpy size 87f count 100000 offset 3 took 144744 us > memcpy size 1000 count 100000 offset 0 took 232057 us > memcpy size 1000 count 100000 offset 1 took 254319 us > memcpy size 1000 count 100000 offset 3 took 256973 us > memcpy size 1000 count 100000 offset 4 took 257655 us > memcpy size 1000 count 100000 offset 5 took 259456 us > memcpy size 1000 count 100000 offset 7 took 260849 us > memcpy size 1000 count 100000 offset 8 took 232347 us > memcpy size 1000 count 100000 offset 9 took 254330 us > memcpy size 3000 count 50000 offset 0 took 382376 us > memcpy size 3000 count 50000 offset 1 took 389872 us > memcpy size 3000 count 50000 offset 3 took 385310 us > memcpy size 3000 count 50000 offset 4 took 389748 us > memcpy size 3000 count 50000 offset 5 took 391707 us > memcpy size 3000 count 50000 offset 7 took 386778 us > memcpy size 3000 count 50000 offset 8 took 385691 us > memcpy size 3000 count 50000 offset 9 took 392030 us > > The assembly routine is measurably better. > > [1] https://pastebin.com/DRyECNQW > > > Changes in v9: > - Alphabetize new entries in libc.abilist (to pass checks) > - Fix a couple of typos causing powerpc not to build > (build-many-glibcs) > - Use __inline rather than inline so c89 compiles (build-many-glibcs) Ah, sorry, I missed the v9 here -- I'd made a hwprobe-v9 testing branch with the intent of fixing the failures, but forgot it was actually your v8. So I thought I'd already looked at this. I'm testing this again on top of master, just to make sure. What I'm testing is here , I'll push it assuming it passes the test on my end too. Thanks! > > Changes in v8: > - Fix missed 2.39 in abilists (Joseph) > - Just return -r (Florian) > > Changes in v7: > - Bumped Versions up to 2.39 (Joseph) > - Used INTERNAL_SYSCALL_CALL, and return positive errno to match > pthreads API (Florian). > - Remove __THROW since it creates a warning in combination with the > fortified access decorators. > - Use INTERNAL_VSYSCALL_CALL (Florian) > - Remove __THROW from function pointer type, as it creates warnings > together with __fortified_attr_access. > - Introduced static inline helper (Richard) > - Use new helper function in memcpy ifunc selector (Richard) > > Changes in v6: > - Prefixed __riscv_hwprobe() parameters names with __ to avoid user > macro namespace pollution (Joseph) > - Introduced riscv-ifunc.h for multi-arg ifunc selectors. > - Fix a couple regressions in the assembly from v5 :/ > - Use passed hwprobe pointer in memcpy ifunc selector. > > Changes in v5: > - Do unaligned word access for final trailing bytes (Richard) > > Changes in v4: > - Remove __USE_GNU (Florian) > - __nonnull, __wur, __THROW, and __fortified_attr_access decorations > (Florian) > - change long to long int (Florian) > - Fix comment formatting (Florian) > - Update backup kernel header content copy. > - Fix function declaration formatting (Florian) > - Changed export versions to 2.38 > - Fixed comment style (Florian) > > Changes in v3: > - Update argument types to match v4 kernel interface > - Add the "return" to the vsyscall > - Fix up vdso arg types to match kernel v4 version > - Remove ifdef around INLINE_VSYSCALL (Adhemerval) > - Word align dest for large memcpy()s. > - Add tags > - Remove spurious blank line from sysdeps/riscv/memcpy.c > > Changes in v2: > - hwprobe.h: Use __has_include and duplicate Linux content to make > compilation work when Linux headers are absent (Adhemerval) > - hwprobe.h: Put declaration under __USE_GNU (Adhemerval) > - Use INLINE_SYSCALL_CALL (Adhemerval) > - Update versions > - Update UNALIGNED_MASK to match kernel v3 series. > - Add vDSO interface > - Used _MASK instead of _FAST value itself. > > Evan Green (6): > riscv: Add Linux hwprobe syscall support > riscv: Add hwprobe vdso call support > riscv: Add __riscv_hwprobe pointer to ifunc calls > riscv: Enable multi-arg ifunc resolvers > riscv: Add ifunc helper method to hwprobe.h > riscv: Add and use alignment-ignorant memcpy > > include/libc-symbols.h | 28 ++-- > sysdeps/riscv/dl-irel.h | 8 +- > sysdeps/riscv/memcopy.h | 26 ++++ > sysdeps/riscv/memcpy.c | 63 ++++++++ > sysdeps/riscv/memcpy_noalignment.S | 138 ++++++++++++++++++ > sysdeps/riscv/riscv-ifunc.h | 27 ++++ > sysdeps/unix/sysv/linux/dl-vdso-setup.c | 10 ++ > sysdeps/unix/sysv/linux/dl-vdso-setup.h | 3 + > sysdeps/unix/sysv/linux/riscv/Makefile | 8 +- > sysdeps/unix/sysv/linux/riscv/Versions | 3 + > sysdeps/unix/sysv/linux/riscv/hwprobe.c | 47 ++++++ > .../unix/sysv/linux/riscv/memcpy-generic.c | 24 +++ > .../unix/sysv/linux/riscv/rv32/libc.abilist | 1 + > .../unix/sysv/linux/riscv/rv64/libc.abilist | 1 + > sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h | 107 ++++++++++++++ > sysdeps/unix/sysv/linux/riscv/sysdep.h | 1 + > 16 files changed, 478 insertions(+), 17 deletions(-) > create mode 100644 sysdeps/riscv/memcopy.h > create mode 100644 sysdeps/riscv/memcpy.c > create mode 100644 sysdeps/riscv/memcpy_noalignment.S > create mode 100644 sysdeps/riscv/riscv-ifunc.h > create mode 100644 sysdeps/unix/sysv/linux/riscv/hwprobe.c > create mode 100644 sysdeps/unix/sysv/linux/riscv/memcpy-generic.c > create mode 100644 sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h