From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752892AbbICJLD (ORCPT ); Thu, 3 Sep 2015 05:11:03 -0400 Received: from mga09.intel.com ([134.134.136.24]:37890 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752792AbbICJLA (ORCPT ); Thu, 3 Sep 2015 05:11:00 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,461,1437462000"; d="scan'208";a="781789309" Subject: Re: [PATCH v2 1/4] perf tests: take into account address of each objdump line To: Jan Stancek References: Cc: linux-kernel@vger.kernel.org, acme@kernel.org, jolsa@kernel.org, dsahern@gmail.com, cjashfor@linux.vnet.ibm.com, fweisbec@gmail.com, mingo@kernel.org, namhyung@kernel.org, paulus@samba.org, a.p.zijlstra@chello.nl From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <55E80DFA.7090609@intel.com> Date: Thu, 3 Sep 2015 12:08:10 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/09/15 11:19, Jan Stancek wrote: > objdump output can contain repeated bytes. At the moment test reads > all output sequentially, assuming each address is represented in > output only once: > > ffffffff8164efb3 : > ffffffff8164efb3: c1 5d 00 eb rcrl $0xeb,0x0(%rbp) > ffffffff8164efb7: 00 4c 8b 5c add %cl,0x5c(%rbx,%rcx,4) > > ffffffff8164efb8 : > ffffffff8164efb8: 4c 8b 5c 24 30 mov 0x30(%rsp),%r11 > ffffffff8164efbd: 4c 8b 54 24 38 mov 0x38(%rsp),%r10 > > Store objdump output to buffer according to offset calculated > from address on each line. > > Signed-off-by: Jan Stancek > Cc: Arnaldo Carvalho de Melo > Cc: Jiri Olsa > Cc: Adrian Hunter > Cc: David Ahern > Cc: Corey Ashford > Cc: Frederic Weisbecker > Cc: Ingo Molnar > Cc: Namhyung Kim > Cc: Paul Mackerras > Cc: Peter Zijlstra Apart from a couple of nitpicks below: Acked-by: Adrian Hunter > --- > tools/perf/tests/code-reading.c | 51 ++++++++++++++++++++++++++++++----------- > 1 file changed, 38 insertions(+), 13 deletions(-) > > Changes in v2: > patch split into series > > diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c > index 39c784a100a9..38ee90bc2228 100644 > --- a/tools/perf/tests/code-reading.c > +++ b/tools/perf/tests/code-reading.c > @@ -33,20 +33,20 @@ static unsigned int hex(char c) > return c - 'A' + 10; > } > > -static void read_objdump_line(const char *line, size_t line_len, void **buf, > - size_t *len) > +static size_t read_objdump_line(const char *line, size_t line_len, void *buf, > + size_t len) Some (e.g. checkpatch) suggest that alignment should match open parenthesis > { > const char *p; > - size_t i; > + size_t i, j = 0; > > /* Skip to a colon */ > p = strchr(line, ':'); > if (!p) > - return; > + return 0; > i = p + 1 - line; > > /* Read bytes */ > - while (*len) { > + while (j < len) { > char c1, c2; > > /* Skip spaces */ > @@ -65,20 +65,26 @@ static void read_objdump_line(const char *line, size_t line_len, void **buf, > if (i < line_len && line[i] && !isspace(line[i])) > break; > /* Store byte */ > - *(unsigned char *)*buf = (hex(c1) << 4) | hex(c2); > - *buf += 1; > - *len -= 1; > + *(unsigned char *)buf = (hex(c1) << 4) | hex(c2); > + buf += 1; > + j++; > } > + /* return number of successfully read bytes */ > + return j; > } > > -static int read_objdump_output(FILE *f, void **buf, size_t *len) > +static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr) > { > char *line = NULL; > - size_t line_len; > + size_t line_len, off_last = 0; > ssize_t ret; > int err = 0; > + u64 addr; > + > + while (off_last < *len) { > + size_t off, read_bytes, written_bytes; > + unsigned char tmp[BUFSZ]; > > - while (1) { > ret = getline(&line, &line_len, f); > if (feof(f)) > break; > @@ -87,9 +93,28 @@ static int read_objdump_output(FILE *f, void **buf, size_t *len) > err = -1; > break; > } > - read_objdump_line(line, ret, buf, len); > + > + /* read objdump data into temporary buffer */ > + read_bytes = read_objdump_line(line, ret, tmp, sizeof(tmp)); > + if (!read_bytes) > + continue; > + > + if (sscanf(line, "%"PRIx64, &addr) != 1) > + continue; > + > + /* copy it from temporary buffer to 'buf' according > + * to address on current objdump line */ The preferred style for long (multi-line) comments is: /* * Copy it from temporary buffer to 'buf' according * to address on current objdump line. */ > + off = addr - start_addr; > + if (off >= *len) > + break; > + written_bytes = MIN(read_bytes, *len - off); We don't use MIN. Use min() instead. > + memcpy(buf + off, tmp, written_bytes); > + off_last = off + written_bytes; > } > > + /* len returns number of bytes that could not be read */ > + *len -= off_last; > + > free(line); > > return err; > @@ -120,7 +145,7 @@ static int read_via_objdump(const char *filename, u64 addr, void *buf, > return -1; > } > > - ret = read_objdump_output(f, &buf, &len); > + ret = read_objdump_output(f, buf, &len, addr); > if (len) { > pr_debug("objdump read too few bytes\n"); > if (!ret) >