From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by kanga.kvack.org (Postfix) with ESMTP id 2FB426B000D for ; Tue, 2 Oct 2018 07:03:48 -0400 (EDT) Received: by mail-pl1-f199.google.com with SMTP id 71-v6so1461453plb.11 for ; Tue, 02 Oct 2018 04:03:48 -0700 (PDT) Received: from mga07.intel.com (mga07.intel.com. [134.134.136.100]) by mx.google.com with ESMTPS id w24-v6si11465960plp.110.2018.10.02.04.03.46 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Oct 2018 04:03:47 -0700 (PDT) Date: Tue, 2 Oct 2018 14:03:38 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCHv3 4/6] tools/gup_benchmark: Allow user specified file Message-ID: <20181002110338.fw7d4jv5e5a6yd4v@black.fi.intel.com> References: <20180921223956.3485-1-keith.busch@intel.com> <20180921223956.3485-5-keith.busch@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180921223956.3485-5-keith.busch@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Keith Busch Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dave Hansen , Dan Williams On Fri, Sep 21, 2018 at 10:39:54PM +0000, Keith Busch wrote: > The gup benchmark by default maps anonymous memory. This patch allows a > user to specify a file to map, providing a means to test various > file backings, like device and filesystem DAX. > > Cc: Kirill Shutemov > Cc: Dave Hansen > Cc: Dan Williams > Signed-off-by: Keith Busch > --- > tools/testing/selftests/vm/gup_benchmark.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/vm/gup_benchmark.c b/tools/testing/selftests/vm/gup_benchmark.c > index b2082df8beb4..f2c99e2436f8 100644 > --- a/tools/testing/selftests/vm/gup_benchmark.c > +++ b/tools/testing/selftests/vm/gup_benchmark.c > @@ -33,9 +33,12 @@ int main(int argc, char **argv) > unsigned long size = 128 * MB; > int i, fd, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0; > int cmd = GUP_FAST_BENCHMARK; > + int file_map = -1; > + int flags = MAP_ANONYMOUS | MAP_PRIVATE; > + char *file = NULL; > char *p; > > - while ((opt = getopt(argc, argv, "m:r:n:tTLU")) != -1) { > + while ((opt = getopt(argc, argv, "m:r:n:f:tTLU")) != -1) { > switch (opt) { > case 'm': > size = atoi(optarg) * MB; > @@ -61,11 +64,22 @@ int main(int argc, char **argv) > case 'w': > write = 1; > break; > + case 'f': > + file = optarg; > + flags &= ~(MAP_PRIVATE | MAP_ANONYMOUS); > + flags |= MAP_SHARED; Why do we want to assume shared mapping if a file is passed? Private-file mapping is also valid target for the benchmark. Maybe a separate option for shared? It would keep options more independent. BTW, we can make a default file /dev/zero and don't have MAP_ANONYMOUS in the flags: private mapping of /dev/zero would produce anonymous mapping. No need in masking out MAP_ANONYMOUS on -f and no branch on 'if (file)' below. > + break; > default: > return -1; > } > } > > + if (file) { > + file_map = open(file, O_RDWR|O_CREAT); > + if (file_map < 0) > + perror("open"), exit(file_map); > + } > + > gup.nr_pages_per_call = nr_pages; > gup.flags = write; > > @@ -73,8 +87,7 @@ int main(int argc, char **argv) > if (fd == -1) > perror("open"), exit(1); > > - p = mmap(NULL, size, PROT_READ | PROT_WRITE, > - MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); > + p = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, file_map, 0); > if (p == MAP_FAILED) > perror("mmap"), exit(1); > gup.addr = (unsigned long)p; > -- > 2.14.4 > -- Kirill A. Shutemov