From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f47.google.com (mail-ot1-f47.google.com [209.85.210.47]) (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 6EC892AF1C for ; Mon, 11 Nov 2024 17:09:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731344960; cv=none; b=UnM3RBn1m8KHOEZQ6NI9S2xPZyATK3DG1jCIOzwMO1uqSElyr8RRawcZdJY81u70h92ybhWbUqUkocCruPTTg8kd9XcPv1M36dPeJA1QIX6u4aDHk0PKXEg3i4kK6Xx93n8k5a6uA6Gmzp0dkylHjKIOiYr8K4cYyVfjvUahKHc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731344960; c=relaxed/simple; bh=FWFU++bHMwg8DYm85y0XjcNuvtTGRgPVpTC09F8Y7xE=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=gydyy0aE0Y1tlrt1PmYrIzeCDWS7dmkzMOLEBwUDfiqiTj9uX+7pIsgE24mKQyJ0N4ag1XkYE7YZNv2BJQF6qOvenTKKErucW2bcqOT7wAD3tSO+mvIig+aXndgWDPche1d/Fl3Br11lHkJJB1jr/+qp8uXyuup5uco9notpFqU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=K6AMPVyq; arc=none smtp.client-ip=209.85.210.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="K6AMPVyq" Received: by mail-ot1-f47.google.com with SMTP id 46e09a7af769-71811aba576so2984535a34.1 for ; Mon, 11 Nov 2024 09:09:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1731344956; x=1731949756; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:from:subject:user-agent:mime-version:date:message-id:from:to :cc:subject:date:message-id:reply-to; bh=f6fLv7NDwAwgh2zTfiGl9xXcUzRaOQnOkOpbb/tKGe0=; b=K6AMPVyqy4twA+xwqmYbYJytw4z2hIsW+NQr4mbx7rDwRPZsc7P3UQzXYOiXxOq5vz XnHipzTeBHtAZ4NLD7DD3NVjGPdJSVG+5w9/M8KmNpvAxX0J/6D56QJCwzH8bo9RIXC1 RjdzoihivyhdzLBock49IEDiK9K/D1UwDgT6p0nSdcc2cJxWdeJOAnvVijHqD7Z1QIVo qTaz8qanaTOUa2K87l9n4vw5pEHAGB0h1ubA64MA0kDtmTyQYek5/O25pB951VjmR35Z LwOO2k2vpmltuxR3uWFQj8R7IKSsq/qtuB82SQ4QMz8oxK9lo7vWbq2nP8U8rg0eyxq2 cNvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731344956; x=1731949756; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:from:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=f6fLv7NDwAwgh2zTfiGl9xXcUzRaOQnOkOpbb/tKGe0=; b=pHxQYRu30iIece7Pbdc7a0La3XuPbqGyLCqjZD4Pj6snqjmMBAXp2dBaj5kqX2JTFM H0gFfD8gnFArOt8prRodXzZ5Tt0SRtuwrZzyEZUQJh60N3yhOCOm8klSXMv0+eOpd7AH hdJ/e4d3uWxHxWNDZcxZg59VxjbsrJIGkhnSvld17ile5PDxctCOYjht+WHD/sVsCUd5 smDiNRVmfRoWG/vAMN+dSR3poSLsN1iFEN00iJ9xr4aF0W7ygVjXudhksPEAraIMAKt6 Jc8bCFow32oyrNfyLmRdlE+v5cHBUbe4IVJpzacRat/1pdjFJ56ilHDg1Y5vibXxDEcz FLQg== X-Forwarded-Encrypted: i=1; AJvYcCXqFCnvtzDKfNHDlJfBEzUnZBGdjzOUIBu71Ag1nTBhnLZm/72VMcKlj5GQ9JXAMUlz4AimwemVaqtuEFM=@vger.kernel.org X-Gm-Message-State: AOJu0YzrolYQ3sfZ/kLgl6q/5cDaVkpWvqBey4MA1PZ381U+YbPQl+Qc wHIUdpQCqYocjqmwiVoW4G9ZEj8iBBGiiXgvBiKm8Wf3r7kNjObPz8M8NZFun/Q= X-Google-Smtp-Source: AGHT+IFNZamT2bZFDaSjw1Yl3jaxXvbQV8DNZNoPpnlYjKrFHE1JGXIOAPe3KflgKlcoZRhw+QrWwg== X-Received: by 2002:a9d:4c12:0:b0:710:e1e4:1bc3 with SMTP id 46e09a7af769-71a1b013b2bmr6535107a34.6.1731344956471; Mon, 11 Nov 2024 09:09:16 -0800 (PST) Received: from [192.168.1.116] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-71a107eb5desm2315700a34.3.2024.11.11.09.09.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 11 Nov 2024 09:09:15 -0800 (PST) Message-ID: <31db6462-83d1-48b6-99b9-da38c399c767@kernel.dk> Date: Mon, 11 Nov 2024 10:09:14 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 08/15] mm/filemap: add read support for RWF_UNCACHED From: Jens Axboe To: Christoph Hellwig Cc: "Kirill A. Shutemov" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, hannes@cmpxchg.org, clm@meta.com, linux-kernel@vger.kernel.org, willy@infradead.org References: <20241110152906.1747545-1-axboe@kernel.dk> <20241110152906.1747545-9-axboe@kernel.dk> <221590fa-b230-426a-a8ec-7f18b74044b8@kernel.dk> <04fd04b3-c19e-4192-b386-0487ab090417@kernel.dk> Content-Language: en-US In-Reply-To: <04fd04b3-c19e-4192-b386-0487ab090417@kernel.dk> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/11/24 8:17 AM, Jens Axboe wrote: > On 11/11/24 8:16 AM, Christoph Hellwig wrote: >> On Mon, Nov 11, 2024 at 07:12:35AM -0700, Jens Axboe wrote: >>> Ok thanks, let me take a look at that and create a test case that >>> exercises that explicitly. >> >> Please add RWF_UNCACHED to fsstress.c in xfstests also. That is our >> exerciser for concurrent issuing of different I/O types to hit these >> kinds of corner cases. > > Sure, can do. Not familiar with fsstress at all, but something like the below? Will use it if available, if it gets EOPNOTSUPP it'll just fallback to using writev_f()/readv_f() instead. Did give it a quick test spin and I see uncached reads and writes on the kernel that supports it. diff --git a/ltp/fsstress.c b/ltp/fsstress.c index 3d248ee25791..6430f10efbc7 100644 --- a/ltp/fsstress.c +++ b/ltp/fsstress.c @@ -82,6 +82,12 @@ static int renameat2(int dfd1, const char *path1, #define RENAME_WHITEOUT (1 << 2) /* Whiteout source */ #endif +#ifndef RWF_UNCACHED +#define RWF_UNCACHED 0x80 +#endif + +static int have_rwf_uncached = 1; + #define FILELEN_MAX (32*4096) typedef enum { @@ -117,6 +123,7 @@ typedef enum { OP_COLLAPSE, OP_INSERT, OP_READ, + OP_READ_UNCACHED, OP_READLINK, OP_READV, OP_REMOVEFATTR, @@ -143,6 +150,7 @@ typedef enum { OP_URING_READ, OP_URING_WRITE, OP_WRITE, + OP_WRITE_UNCACHED, OP_WRITEV, OP_EXCHANGE_RANGE, OP_LAST @@ -248,6 +256,7 @@ void zero_f(opnum_t, long); void collapse_f(opnum_t, long); void insert_f(opnum_t, long); void unshare_f(opnum_t, long); +void read_uncached_f(opnum_t, long); void read_f(opnum_t, long); void readlink_f(opnum_t, long); void readv_f(opnum_t, long); @@ -273,6 +282,7 @@ void unlink_f(opnum_t, long); void unresvsp_f(opnum_t, long); void uring_read_f(opnum_t, long); void uring_write_f(opnum_t, long); +void write_uncached_f(opnum_t, long); void write_f(opnum_t, long); void writev_f(opnum_t, long); void exchangerange_f(opnum_t, long); @@ -315,6 +325,7 @@ struct opdesc ops[OP_LAST] = { [OP_COLLAPSE] = {"collapse", collapse_f, 1, 1 }, [OP_INSERT] = {"insert", insert_f, 1, 1 }, [OP_READ] = {"read", read_f, 1, 0 }, + [OP_READ_UNCACHED] = {"read_uncached", read_uncached_f, 1, 0 }, [OP_READLINK] = {"readlink", readlink_f, 1, 0 }, [OP_READV] = {"readv", readv_f, 1, 0 }, /* remove (delete) extended attribute */ @@ -346,6 +357,7 @@ struct opdesc ops[OP_LAST] = { [OP_URING_WRITE] = {"uring_write", uring_write_f, 1, 1 }, [OP_WRITE] = {"write", write_f, 4, 1 }, [OP_WRITEV] = {"writev", writev_f, 4, 1 }, + [OP_WRITE_UNCACHED]= {"write_uncaced", write_uncached_f,4, 1 }, [OP_EXCHANGE_RANGE]= {"exchangerange", exchangerange_f, 2, 1 }, }, *ops_end; @@ -4635,6 +4647,76 @@ readv_f(opnum_t opno, long r) close(fd); } +void +read_uncached_f(opnum_t opno, long r) +{ + int e; + pathname_t f; + int fd; + int64_t lr; + off64_t off; + struct stat64 stb; + int v; + char st[1024]; + struct iovec iov; + + if (!have_rwf_uncached) { + readv_f(opno, r); + return; + } + + init_pathname(&f); + if (!get_fname(FT_REGFILE, r, &f, NULL, NULL, &v)) { + if (v) + printf("%d/%lld: read - no filename\n", procid, opno); + free_pathname(&f); + return; + } + fd = open_path(&f, O_RDONLY); + e = fd < 0 ? errno : 0; + check_cwd(); + if (fd < 0) { + if (v) + printf("%d/%lld: read - open %s failed %d\n", + procid, opno, f.path, e); + free_pathname(&f); + return; + } + if (fstat64(fd, &stb) < 0) { + if (v) + printf("%d/%lld: read - fstat64 %s failed %d\n", + procid, opno, f.path, errno); + free_pathname(&f); + close(fd); + return; + } + inode_info(st, sizeof(st), &stb, v); + if (stb.st_size == 0) { + if (v) + printf("%d/%lld: read - %s%s zero size\n", procid, opno, + f.path, st); + free_pathname(&f); + close(fd); + return; + } + lr = ((int64_t)random() << 32) + random(); + off = (off64_t)(lr % stb.st_size); + iov.iov_len = (random() % FILELEN_MAX) + 1; + iov.iov_base = malloc(iov.iov_len); + e = preadv2(fd, &iov, 1, off, RWF_UNCACHED) < 0 ? errno : 0; + if (e == EOPNOTSUPP) { + have_rwf_uncached = 0; + e = 0; + } + free(iov.iov_base); + if (v) + printf("%d/%lld: read uncached %s%s [%lld,%d] %d\n", + procid, opno, f.path, st, (long long)off, + (int)iov.iov_len, e); + free_pathname(&f); + close(fd); +} + void removefattr_f(opnum_t opno, long r) { @@ -5509,6 +5591,70 @@ writev_f(opnum_t opno, long r) close(fd); } +void +write_uncached_f(opnum_t opno, long r) +{ + int e; + pathname_t f; + int fd; + int64_t lr; + off64_t off; + struct stat64 stb; + int v; + char st[1024]; + struct iovec iov; + + if (!have_rwf_uncached) { + writev_f(opno, r); + return; + } + + init_pathname(&f); + if (!get_fname(FT_REGm, r, &f, NULL, NULL, &v)) { + if (v) + printf("%d/%lld: write - no filename\n", procid, opno); + free_pathname(&f); + return; + } + fd = open_path(&f, O_WRONLY); + e = fd < 0 ? errno : 0; + check_cwd(); + if (fd < 0) { + if (v) + printf("%d/%lld: write - open %s failed %d\n", + procid, opno, f.path, e); + free_pathname(&f); + return; + } + if (fstat64(fd, &stb) < 0) { + if (v) + printf("%d/%lld: write - fstat64 %s failed %d\n", + procid, opno, f.path, errno); + free_pathname(&f); + close(fd); + return; + } + inode_info(st, sizeof(st), &stb, v); + lr = ((int64_t)random() << 32) + random(); + off = (off64_t)(lr % MIN(stb.st_size + (1024 * 1024), MAXFSIZE)); + off %= maxfsize; + iov.iov_len = (random() % FILELEN_MAX) + 1; + iov.iov_base = malloc(iov.iov_len); + memset(iov.iov_base, nameseq & 0xff, iov.iov_len); + e = pwritev2(fd, &iov, 1, off, RWF_UNCACHED) < 0 ? errno : 0; + free(iov.iov_base); + if (v) + printf("%d/%lld: write uncached %s%s [%lld,%d] %d\n", + procid, opno, f.path, st, (long long)off, + (int)iov.iov_len, e); + free_pathname(&f); + close(fd); + if (e == EOPNOTSUPP) { + writev_f(opno, r); + have_rwf_uncached = 0; + } +} + char * xattr_flag_to_string(int flag) { -- Jens Axboe