From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57066C4320E for ; Tue, 17 Aug 2021 14:53:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E4DF60F41 for ; Tue, 17 Aug 2021 14:53:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238030AbhHQOyG (ORCPT ); Tue, 17 Aug 2021 10:54:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:56766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236592AbhHQOyG (ORCPT ); Tue, 17 Aug 2021 10:54:06 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1211B60F41; Tue, 17 Aug 2021 14:53:32 +0000 (UTC) Date: Tue, 17 Aug 2021 10:53:26 -0400 From: Steven Rostedt To: "Tzvetomir Stoyanov (VMware)" Cc: linux-trace-devel@vger.kernel.org Subject: Re: [PATCH v2 24/87] trace-cmd library: Add local helper function for data compression Message-ID: <20210817105326.0ef34247@oasis.local.home> In-Reply-To: <20210729050959.12263-25-tz.stoyanov@gmail.com> References: <20210729050959.12263-1-tz.stoyanov@gmail.com> <20210729050959.12263-25-tz.stoyanov@gmail.com> X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Thu, 29 Jul 2021 08:08:56 +0300 "Tzvetomir Stoyanov (VMware)" wrote: > The newly added helper functions read data from a file and compress it, > before writing into the trace file. The trace data is comressed in > chunks, which are page aligned. A new local define is introduced: > PAGES_IN_CHUNK > which can be used to tune how big a compression chunk is. > > Signed-off-by: Tzvetomir Stoyanov (VMware) > --- > lib/trace-cmd/trace-output.c | 70 ++++++++++++++++++++++++++++++++---- > 1 file changed, 64 insertions(+), 6 deletions(-) > > diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c > index 6a44a99b..90625c4e 100644 > --- a/lib/trace-cmd/trace-output.c > +++ b/lib/trace-cmd/trace-output.c > @@ -285,18 +285,26 @@ static unsigned long get_size(const char *file) > return size; > } > > -static tsize_t copy_file_fd(struct tracecmd_output *handle, int fd) > +static tsize_t copy_file_fd(struct tracecmd_output *handle, int fd, unsigned long long max) > { > + tsize_t rsize = 0; > tsize_t size = 0; > char buf[BUFSIZ]; > stsize_t r; > > do { > - r = read(fd, buf, BUFSIZ); > + if (max > 0 && (max - size) < BUFSIZ) > + rsize = (max - size); > + else > + rsize = BUFSIZ; > + > + r = read(fd, buf, rsize); > if (r > 0) { > size += r; > if (do_write_check(handle, buf, r)) > return 0; > + if (max > 0 && size >= max) > + break; > } > } while (r > 0); I think this would be a bit cleaner: static tsize_t copy_file_fd(struct tracecmd_output *handle, int fd, unsigned long long max) { tsize_t rsize = BUFSIZ; tsize_t size = 0; char buf[BUFSIZ]; stsize_t r; do { if (max && rsize > max) rsize = max; r = read(fd, buf, rsize); if (r > 0) { size += r; if (do_write_check(handle, buf, r)) return 0; if (max) { max -= r; if (!max) break; } } } while (r > 0); return size; } > > @@ -314,12 +322,62 @@ static tsize_t copy_file(struct tracecmd_output *handle, > tracecmd_warning("Can't read '%s'", file); > return 0; > } > - size = copy_file_fd(handle, fd); > + size = copy_file_fd(handle, fd, 0); > close(fd); > > return size; > } > > +#define PAGES_IN_CHUNK 10 > +__hidden unsigned long long out_copy_fd_compress(struct tracecmd_output *handle, The above name is also hard to understand. "out_copy_fd_compress"? Would "copy_out_fd_compress()" be better? Also, why is it __hidden and not static. it's not used outside this file. If it gets used outside this file in a follow up patch, please convert it from static to __hidden then. -- Steve > + int fd, unsigned long long max, > + unsigned long long *write_size) > +{ > + unsigned long long rsize = 0; > + unsigned long long wsize = 0; > + unsigned long long size; > + int ret; > + > + if (handle->compress) { > + rsize = max; > + ret = tracecmd_compress_copy_from(handle->compress, fd, > + PAGES_IN_CHUNK * handle->page_size, > + &rsize, &wsize); > + if (ret < 0) > + return 0; > + > + size = rsize; > + if (write_size) > + *write_size = wsize; > + } else { > + size = copy_file_fd(handle, fd, max); > + if (write_size) > + *write_size = size; > + } > + > + return size; > +} > + > +static tsize_t copy_file_compress(struct tracecmd_output *handle, > + const char *file, unsigned long long *write_size) > +{ > + int ret; > + int fd; > + > + fd = open(file, O_RDONLY); > + if (fd < 0) { > + tracecmd_warning("Can't read '%s'", file); > + return 0; > + } > + > + ret = out_copy_fd_compress(handle, fd, 0, write_size); > + if (!ret) > + tracecmd_warning("Can't compress '%s'", file); > + > + close(fd); > + return ret; > +} > + > /* > * Finds the path to the debugfs/tracing > * Allocates the string and stores it. > @@ -516,7 +574,7 @@ static int read_header_files(struct tracecmd_output *handle, bool compress) > endian8 = convert_endian_8(handle, size); > if (do_write_check(handle, &endian8, 8)) > goto out_close; > - check_size = copy_file_fd(handle, fd); > + check_size = copy_file_fd(handle, fd, 0); > close(fd); > if (size != check_size) { > tracecmd_warning("wrong size for '%s' size=%lld read=%lld", path, size, check_size); > @@ -542,7 +600,7 @@ static int read_header_files(struct tracecmd_output *handle, bool compress) > endian8 = convert_endian_8(handle, size); > if (do_write_check(handle, &endian8, 8)) > goto out_close; > - check_size = copy_file_fd(handle, fd); > + check_size = copy_file_fd(handle, fd, 0); > close(fd); > if (size != check_size) { > tracecmd_warning("wrong size for '%s'", path); > @@ -1984,7 +2042,7 @@ __hidden int out_write_cpu_data(struct tracecmd_output *handle, > if (lseek64(data[i].fd, data[i].offset, SEEK_SET) == (off64_t)-1) > goto out_free; > if (data[i].size) { > - read_size = copy_file_fd(handle, data[i].fd); > + read_size = copy_file_fd(handle, data[i].fd, data[i].size); > if (read_size != data_files[i].file_size) { > errno = EINVAL; > tracecmd_warning("did not match size of %lld to %lld",