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Subject: Re: [PATCH] perf vendor events: fix processing for xfs
To:     Arnaldo Carvalho de Melo <acme@kernel.org>
References: <1521047452-28565-1-git-send-email-john.garry@huawei.com>
 <20180314185355.GC27335@kernel.org>
 <fa4f4c83-1a1a-761f-9259-ce21ee000fc3@huawei.com>
 <20180314202643.GG27335@kernel.org>
CC:     <peterz@infradead.org>, <mingo@redhat.com>,
        <alexander.shishkin@linux.intel.com>, <jolsa@redhat.com>,
        <namhyung@kernel.org>, <ak@linux.intel.com>, <wcohen@redhat.com>,
        <sukadev@linux.vnet.ibm.com>, <linux-kernel@vger.kernel.org>,
        <linuxarm@huawei.com>
From:   John Garry <john.garry@huawei.com>
Message-ID: <4f8d9085-8415-5b99-daee-34994ae95cb1@huawei.com>
Date:   Wed, 14 Mar 2018 20:58:33 +0000
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On 14/03/2018 20:26, Arnaldo Carvalho de Melo wrote:
> Em Wed, Mar 14, 2018 at 07:39:25PM +0000, John Garry escreveu:
>> On 14/03/2018 18:53, Arnaldo Carvalho de Melo wrote:
>>> Em Thu, Mar 15, 2018 at 01:10:52AM +0800, John Garry escreveu:
>>>> In the recently introduced support for vendor subdirectory,
>>>> the checking for directory entries under xfs (or any other fs
>>>> which does not support dirent.d_type) is missing the check
>>>> for links for current and parent directory. This can result
>>>> in a broken pmu_events.c being generated.
>>>>
>>>> Fix this by adding the appropriate check in is_leaf_dir().
>>>
>>> So I'll lookup the patch that introduced the patch and squash this one
>>> with it, so that we don't break 'git bisect' on ppc.
>>
>> Right, so it's going to be "perf vendor events: add support for pmu events
>> vendor subdirectory".
>>
>> BTW, I don't think it's specifically ppc which was broken, but just when
>> building from xfs.
>>
>> Much appreciated,
>> John
>
> This is the ammended cset, and yes, I mentioned just XFS not ppc, added
> Sukadev to the CC list and the link to your patch that he tested. Also
> stamped his Tested-by there.
>
> This will all go again the container build test set before a new pull
> req to Ingo, where I'll avoid sending the previous 31 patches to the
> mailing list, just the ones that came after it, as perf/core keeps
> growing :-)

It looks ok,

Thanks a lot,
John

>
> - Arnaldo
>
> commit d24081387a00d2e10789eb012429144c549598be
> Author: John Garry <john.garry@huawei.com>
> Date:   Thu Mar 8 18:58:29 2018 +0800
>
>     perf vendor events: Add support for pmu events vendor subdirectory
>
>     For some architectures (like arm), it is required to support a vendor
>     subdirectory and not locate all the JSONs for a specific vendor in the
>     same folder.
>
>     This is because all the events for the same vendor will be placed in the
>     same pmu events table, which may cause conflict.  This conflict would be
>     in the instance that a vendor's custom implemented events do have the
>     same meaning on different platforms, so events in the pmu table would
>     conflict. In addition, per list command may show events which are not
>     even supported for a given platform.
>
>     This patch adds support for a arch/vendor/platform directory hierarchy,
>     while maintaining backwards-compatibility for existing arch/platform
>     structure. In this, each platform would always have its own pmu events
>     table.
>
>     In generated file pmu_events.c, each platform table name is in the
>     format pme{_vendor}_platform, like this:
>
>     struct pmu_events_map pmu_events_map[] = {
>     {
>             .cpuid = "0x00000000420f5160",
>             .version = "v1",
>             .type = "core",
>             .table = pme_cavium_thunderx2
>     },
>     {
>             .cpuid = 0,
>             .version = 0,
>             .type = 0,
>             .table = 0,
>     },
>     };
>
>     Signed-off-by: John Garry <john.garry@huawei.com>
>     Acked-by: Jiri Olsa <jolsa@kernel.org>
>     Tested-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
>     Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
>     Cc: Andi Kleen <ak@linux.intel.com>
>     Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
>     Cc: Namhyung Kim <namhyung@kernel.org>
>     Cc: Peter Zijlstra <peterz@infradead.org>
>     Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
>     Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
>     Cc: Will Deacon <will.deacon@arm.com>
>     Cc: William Cohen <wcohen@redhat.com>
>     Cc: linux-arm-kernel@lists.infradead.org
>     Cc: linuxarm@huawei.com
>     Link: http://lkml.kernel.org/r/1520506716-197429-5-git-send-email-john.garry@huawei.com
>     Link: http://lkml.kernel.org/r/1521047452-28565-1-git-send-email-john.garry@huawei.com
>     [ Add missing limits.h include, fixing the build on at least all Alpine Linux versions tested (3.4 to 3.7 + edge), ]
>     [ Applied a patch to fix reading ./.. directories in XFS, see second Link tag ]
>     Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
>
> diff --git a/tools/perf/pmu-events/README b/tools/perf/pmu-events/README
> index 2407abc1d441..655286ff8767 100644
> --- a/tools/perf/pmu-events/README
> +++ b/tools/perf/pmu-events/README
> @@ -28,6 +28,10 @@ sub directory. Thus for the Silvermont X86 CPU:
>  	Cache.json 	Memory.json 	Virtual-Memory.json
>  	Frontend.json 	Pipeline.json
>
> +The JSONs folder for a CPU model/family may be placed in the root arch
> +folder, or may be placed in a vendor sub-folder under the arch folder
> +for instances where the arch and vendor are not the same.
> +
>  Using the JSON files and the mapfile, 'jevents' generates the C source file,
>  'pmu-events.c', which encodes the two sets of tables:
>
> diff --git a/tools/perf/pmu-events/jevents.c b/tools/perf/pmu-events/jevents.c
> index 1d02fafdc34d..0981d313064f 100644
> --- a/tools/perf/pmu-events/jevents.c
> +++ b/tools/perf/pmu-events/jevents.c
> @@ -39,6 +39,7 @@
>  #include <unistd.h>
>  #include <stdarg.h>
>  #include <libgen.h>
> +#include <limits.h>
>  #include <dirent.h>
>  #include <sys/time.h>			/* getrlimit */
>  #include <sys/resource.h>		/* getrlimit */
> @@ -572,7 +573,7 @@ static char *file_name_to_table_name(char *fname)
>  	 * Derive rest of table name from basename of the JSON file,
>  	 * replacing hyphens and stripping out .json suffix.
>  	 */
> -	n = asprintf(&tblname, "pme_%s", basename(fname));
> +	n = asprintf(&tblname, "pme_%s", fname);
>  	if (n < 0) {
>  		pr_info("%s: asprintf() error %s for file %s\n", prog,
>  				strerror(errno), fname);
> @@ -582,7 +583,7 @@ static char *file_name_to_table_name(char *fname)
>  	for (i = 0; i < strlen(tblname); i++) {
>  		c = tblname[i];
>
> -		if (c == '-')
> +		if (c == '-' || c == '/')
>  			tblname[i] = '_';
>  		else if (c == '.') {
>  			tblname[i] = '\0';
> @@ -739,25 +740,80 @@ static int get_maxfds(void)
>  static FILE *eventsfp;
>  static char *mapfile;
>
> +static int is_leaf_dir(const char *fpath)
> +{
> +	DIR *d;
> +	struct dirent *dir;
> +	int res = 1;
> +
> +	d = opendir(fpath);
> +	if (!d)
> +		return 0;
> +
> +	while ((dir = readdir(d)) != NULL) {
> +		if (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."))
> +			continue;
> +
> +		if (dir->d_type == DT_DIR) {
> +			res = 0;
> +			break;
> +		} else if (dir->d_type == DT_UNKNOWN) {
> +			char path[PATH_MAX];
> +			struct stat st;
> +
> +			sprintf(path, "%s/%s", fpath, dir->d_name);
> +			if (stat(path, &st))
> +				break;
> +
> +			if (S_ISDIR(st.st_mode)) {
> +				res = 0;
> +				break;
> +			}
> +		}
> +	}
> +
> +	closedir(d);
> +
> +	return res;
> +}
> +
>  static int process_one_file(const char *fpath, const struct stat *sb,
>  			    int typeflag, struct FTW *ftwbuf)
>  {
> -	char *tblname, *bname  = (char *) fpath + ftwbuf->base;
> +	char *tblname, *bname;
>  	int is_dir  = typeflag == FTW_D;
>  	int is_file = typeflag == FTW_F;
>  	int level   = ftwbuf->level;
>  	int err = 0;
>
> +	if (level == 2 && is_dir) {
> +		/*
> +		 * For level 2 directory, bname will include parent name,
> +		 * like vendor/platform. So search back from platform dir
> +		 * to find this.
> +		 */
> +		bname = (char *) fpath + ftwbuf->base - 2;
> +		for (;;) {
> +			if (*bname == '/')
> +				break;
> +			bname--;
> +		}
> +		bname++;
> +	} else
> +		bname = (char *) fpath + ftwbuf->base;
> +
>  	pr_debug("%s %d %7jd %-20s %s\n",
>  		 is_file ? "f" : is_dir ? "d" : "x",
>  		 level, sb->st_size, bname, fpath);
>
> -	/* base dir */
> -	if (level == 0)
> +	/* base dir or too deep */
> +	if (level == 0 || level > 3)
>  		return 0;
>
> +
>  	/* model directory, reset topic */
> -	if (level == 1 && is_dir) {
> +	if ((level == 1 && is_dir && is_leaf_dir(fpath)) ||
> +	    (level == 2 && is_dir)) {
>  		if (close_table)
>  			print_events_table_suffix(eventsfp);
>
>
> .
>