[PATCH] Add --no-hard-links option to localedef (Bug 23923)

[PATCH] Add --no-hard-links option to localedef (Bug 23923)

[Carlos O'Donell]

[PATCH] Add --no-hard-links option to localedef (bug 23923)

Downstream distributions need consistent sets of hardlinks in
order for rpm to operate effectively. This means that even if
locales are built with a high level of parallelism that the
resulting files need to have consistent hardlink counts. The only
way to achieve this is with a post-install hardlink pass using a
program like 'hardklink' (shipped in Fedora).

If the downstream distro wants to post-process the hardlinks then
the time spent in localedef looking up sibling directories and
processing hardlinks is wasted effort.

To optimize the build and install pass we add a --no-hard-links
option to localedef to avoid doing the hardlink optimziation for
size.

Tested on x86_64 with 'make localedata/install-locale-files'
before and after. Without the patch we have files with 70+
hardlink counts. After the patch and running with --no-hard-links
all link counts are 1.

Signed-off-by: Carlos O'Donell <carlos@redhat.com>
---
 ChangeLog                   | 10 ++++++++++
 locale/programs/localedef.c | 10 ++++++++++
 locale/programs/localedef.h |  1 +
 locale/programs/locfile.c   | 16 +++++++++++++---
 4 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 03887874a2..b9bce8bc8e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2018-11-26  Carlos O'Donell  <carlos@redhat.com>
+
+	[BZ #23923]
+	* locale/programs/localedef.c: Declare boolean hard_links default true.
+	(options): Add --no-hard-links option.
+	(parse_opt): Add OPT_NO_HARD_LINKS case and set hard_links to false.
+	* locale/programs/localedef.h: Declare prototype for hard_links.
+	* locale/programs/locfile.c (write_locale_data): Don't use hard
+	links if hard_links is false.
+
 2018-11-26  Carlos O'Donell  <carlos@redhat.com>
 
 	* scripts/abilist.awk: Handle .tdata. Error for unknown combinations.
diff --git a/locale/programs/localedef.c b/locale/programs/localedef.c
index d718d2e9f4..6c4936be6b 100644
--- a/locale/programs/localedef.c
+++ b/locale/programs/localedef.c
@@ -85,6 +85,9 @@ static bool replace_archive;
 /* If true list archive content.  */
 static bool list_archive;
 
+/* If true create hard links to other locales (default).  */
+bool hard_links = true;
+
 /* Maximum number of retries when opening the locale archive.  */
 int max_locarchive_open_retry = 10;
 
@@ -105,6 +108,7 @@ void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
 #define OPT_BIG_ENDIAN 401
 #define OPT_NO_WARN 402
 #define OPT_WARN 403
+#define OPT_NO_HARD_LINKS 404
 
 /* Definitions of arguments for argp functions.  */
 static const struct argp_option options[] =
@@ -120,6 +124,8 @@ static const struct argp_option options[] =
   { NULL, 0, NULL, 0, N_("Output control:") },
   { "force", 'c', NULL, 0,
     N_("Create output even if warning messages were issued") },
+  { "no-hard-links", OPT_NO_HARD_LINKS, NULL, 0,
+    N_("Do not create hard links between installed locales") },
   { "prefix", OPT_PREFIX, N_("PATH"), 0, N_("Optional output file prefix") },
   { "posix", OPT_POSIX, NULL, 0, N_("Strictly conform to POSIX") },
   { "quiet", OPT_QUIET, NULL, 0,
@@ -389,6 +395,10 @@ parse_opt (int key, char *arg, struct argp_state *state)
       /* Enable the warnings.  */
       set_warnings (arg, true);
       break;
+    case OPT_NO_HARD_LINKS:
+      /* Do not hard link to other locales.  */
+      hard_links = false;
+      break;
     case 'c':
       force_output = 1;
       break;
diff --git a/locale/programs/localedef.h b/locale/programs/localedef.h
index 0083faceab..e2b39e78f3 100644
--- a/locale/programs/localedef.h
+++ b/locale/programs/localedef.h
@@ -118,6 +118,7 @@ extern const char *repertoire_global;
 extern int max_locarchive_open_retry;
 extern bool no_archive;
 extern const char *alias_file;
+extern bool hard_links;
 
 
 /* Prototypes for a few program-wide used functions.  */
diff --git a/locale/programs/locfile.c b/locale/programs/locfile.c
index 32e5f761f2..14c743373d 100644
--- a/locale/programs/locfile.c
+++ b/locale/programs/locfile.c
@@ -702,7 +702,7 @@ write_locale_data (const char *output_path, int catidx, const char *category,
   size_t cnt, step, maxiov;
   int fd;
   char *fname;
-  const char **other_paths;
+  const char **other_paths = NULL;
   uint32_t header[2];
   size_t n_elem;
   struct iovec vec[3];
@@ -828,8 +828,18 @@ failure while writing data for category `%s'"), category);
   close (fd);
 
   /* Compare the file with the locale data files for the same category in
-     other locales, and see if we can reuse it, to save disk space.  */
-  other_paths = siblings (output_path);
+     other locales, and see if we can reuse it, to save disk space.
+     If the user specified --no-hard-link to localedef then hard_links is
+     false, other_paths remains NULL and we skip the optimization below.
+     The use of --no-hard-link is distribution specific since some distros
+     have post-processing hard-link steps and so doing this here is a waste
+     of time.  */
+  if (hard_links)
+    other_paths = siblings (output_path);
+
+  /* If there are other paths, then walk the sibling paths looking for
+     files with the same content so we can hard link and reduce disk
+     space usage.  */
   if (other_paths != NULL)
     {
       struct stat64 fname_stat;
-- 
2.19.1


-- 
Cheers,
Carlos.

Re: [PATCH] Add --no-hard-links option to localedef (Bug 23923)

[Florian Weimer]

* Carlos O'Donell:

> +	[BZ #23923]
> +	* locale/programs/localedef.c: Declare boolean hard_links default true.
> +	(options): Add --no-hard-links option.
> +	(parse_opt): Add OPT_NO_HARD_LINKS case and set hard_links to false.
> +	* locale/programs/localedef.h: Declare prototype for hard_links.
> +	* locale/programs/locfile.c (write_locale_data): Don't use hard
> +	links if hard_links is false.

Looks reasonable to me.

This will need a makefile update, so that we can use this from “make
install-locales”.

Thanks,
Florian

Re: [PATCH] Add --no-hard-links option to localedef (Bug 23923)

[Joseph Myers]

On Mon, 26 Nov 2018, Carlos O'Donell wrote:

> If the downstream distro wants to post-process the hardlinks then
> the time spent in localedef looking up sibling directories and
> processing hardlinks is wasted effort.

Do you have figures for the time involved?

> +     other locales, and see if we can reuse it, to save disk space.
> +     If the user specified --no-hard-link to localedef then hard_links is
> +     false, other_paths remains NULL and we skip the optimization below.
> +     The use of --no-hard-link is distribution specific since some distros
> +     have post-processing hard-link steps and so doing this here is a waste
> +     of time.  */

This should refer to --no-hard-links, not --no-hard-link (twice).

This is not a review of other aspects of the patch (but I approve of 
improving determinism of the locale build, and also have such a hard-link 
post-processing step at Mentor).

-- 
Joseph S. Myers
joseph@codesourcery.com

[PATCHv2] Add --no-hard-links option to localedef (Bug 23923)

[Carlos O'Donell]

On 11/26/18 11:58 AM, Joseph Myers wrote:
> On Mon, 26 Nov 2018, Carlos O'Donell wrote:
> 
>> If the downstream distro wants to post-process the hardlinks then
>> the time spent in localedef looking up sibling directories and
>> processing hardlinks is wasted effort.
> 
> Do you have figures for the time involved?

On a fast SSD the -j1 locale build and install of SUPPORTED locales
is 3% faster, or for me roughly ~10s on a:
"make localedata/install-locale-files DESTDIR=..." iteration.

The option itself ensures that no hard links are present and that may
make the logic of the post-install hardlink creation phase simpler.
So there is more than just performance to consider.

>> +     other locales, and see if we can reuse it, to save disk space.
>> +     If the user specified --no-hard-link to localedef then hard_links is
>> +     false, other_paths remains NULL and we skip the optimization below.
>> +     The use of --no-hard-link is distribution specific since some distros
>> +     have post-processing hard-link steps and so doing this here is a waste
>> +     of time.  */
> 
> This should refer to --no-hard-links, not --no-hard-link (twice).

Fixed.

> This is not a review of other aspects of the patch (but I approve of 
> improving determinism of the locale build, and also have such a hard-link 
> post-processing step at Mentor).

v2
- Fix comments to mention '--no-hard-links'
- Update convenience target to use '--no-hard-links'

[PATCH] Add --no-hard-links option to localedef (bug 23923)

Downstream distributions need consistent sets of hardlinks in
order for rpm to operate effectively. This means that even if
locales are built with a high level of parallelism that the
resulting files need to have consistent hardlink counts. The only
way to achieve this is with a post-install hardlink pass using a
program like 'hardklink' (shipped in Fedora).

If the downstream distro wants to post-process the hardlinks then
the time spent in localedef looking up sibling directories and
processing hardlinks is wasted effort.

To optimize the build and install pass we add a --no-hard-links
option to localedef to avoid doing the hardlink optimziation for
size.

Tested on x86_64 with 'make localedata/install-locale-files'
before and after. Without the patch we have files with 100+
hardlink counts. After the patch and running with --no-hard-links
all link counts are 1. This patch also alters the convenience
target 'make localedata/install-locale-files' to use the new
option.

Signed-off-by: Carlos O'Donell <carlos@redhat.com>
---
 ChangeLog                   | 10 ++++++++++
 locale/programs/localedef.c | 10 ++++++++++
 locale/programs/localedef.h |  1 +
 locale/programs/locfile.c   | 16 +++++++++++++---
 localedata/Makefile         |  2 +-
 5 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 03887874a2..b9bce8bc8e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2018-11-26  Carlos O'Donell  <carlos@redhat.com>
+
+	[BZ #23923]
+	* locale/programs/localedef.c: Declare boolean hard_links default true.
+	(options): Add --no-hard-links option.
+	(parse_opt): Add OPT_NO_HARD_LINKS case and set hard_links to false.
+	* locale/programs/localedef.h: Declare prototype for hard_links.
+	* locale/programs/locfile.c (write_locale_data): Don't use hard
+	links if hard_links is false.
+
 2018-11-26  Carlos O'Donell  <carlos@redhat.com>
 
 	* scripts/abilist.awk: Handle .tdata. Error for unknown combinations.
diff --git a/locale/programs/localedef.c b/locale/programs/localedef.c
index d718d2e9f4..6c4936be6b 100644
--- a/locale/programs/localedef.c
+++ b/locale/programs/localedef.c
@@ -85,6 +85,9 @@ static bool replace_archive;
 /* If true list archive content.  */
 static bool list_archive;
 
+/* If true create hard links to other locales (default).  */
+bool hard_links = true;
+
 /* Maximum number of retries when opening the locale archive.  */
 int max_locarchive_open_retry = 10;
 
@@ -105,6 +108,7 @@ void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
 #define OPT_BIG_ENDIAN 401
 #define OPT_NO_WARN 402
 #define OPT_WARN 403
+#define OPT_NO_HARD_LINKS 404
 
 /* Definitions of arguments for argp functions.  */
 static const struct argp_option options[] =
@@ -120,6 +124,8 @@ static const struct argp_option options[] =
   { NULL, 0, NULL, 0, N_("Output control:") },
   { "force", 'c', NULL, 0,
     N_("Create output even if warning messages were issued") },
+  { "no-hard-links", OPT_NO_HARD_LINKS, NULL, 0,
+    N_("Do not create hard links between installed locales") },
   { "prefix", OPT_PREFIX, N_("PATH"), 0, N_("Optional output file prefix") },
   { "posix", OPT_POSIX, NULL, 0, N_("Strictly conform to POSIX") },
   { "quiet", OPT_QUIET, NULL, 0,
@@ -389,6 +395,10 @@ parse_opt (int key, char *arg, struct argp_state *state)
       /* Enable the warnings.  */
       set_warnings (arg, true);
       break;
+    case OPT_NO_HARD_LINKS:
+      /* Do not hard link to other locales.  */
+      hard_links = false;
+      break;
     case 'c':
       force_output = 1;
       break;
diff --git a/locale/programs/localedef.h b/locale/programs/localedef.h
index 0083faceab..e2b39e78f3 100644
--- a/locale/programs/localedef.h
+++ b/locale/programs/localedef.h
@@ -118,6 +118,7 @@ extern const char *repertoire_global;
 extern int max_locarchive_open_retry;
 extern bool no_archive;
 extern const char *alias_file;
+extern bool hard_links;
 
 
 /* Prototypes for a few program-wide used functions.  */
diff --git a/locale/programs/locfile.c b/locale/programs/locfile.c
index 32e5f761f2..c75eabc886 100644
--- a/locale/programs/locfile.c
+++ b/locale/programs/locfile.c
@@ -702,7 +702,7 @@ write_locale_data (const char *output_path, int catidx, const char *category,
   size_t cnt, step, maxiov;
   int fd;
   char *fname;
-  const char **other_paths;
+  const char **other_paths = NULL;
   uint32_t header[2];
   size_t n_elem;
   struct iovec vec[3];
@@ -828,8 +828,18 @@ failure while writing data for category `%s'"), category);
   close (fd);
 
   /* Compare the file with the locale data files for the same category in
-     other locales, and see if we can reuse it, to save disk space.  */
-  other_paths = siblings (output_path);
+     other locales, and see if we can reuse it, to save disk space.
+     If the user specified --no-hard-links to localedef then hard_links is
+     false, other_paths remains NULL and we skip the optimization below.
+     The use of --no-hard-links is distribution specific since some distros
+     have post-processing hard-link steps and so doing this here is a waste
+     of time.  */
+  if (hard_links)
+    other_paths = siblings (output_path);
+
+  /* If there are other paths, then walk the sibling paths looking for
+     files with the same content so we can hard link and reduce disk
+     space usage.  */
   if (other_paths != NULL)
     {
       struct stat64 fname_stat;
diff --git a/localedata/Makefile b/localedata/Makefile
index 0eea396ad8..b245f0ff54 100644
--- a/localedata/Makefile
+++ b/localedata/Makefile
@@ -423,7 +423,7 @@ $(INSTALL-SUPPORTED-LOCALE-ARCHIVE): install-locales-dir
 	$(build-one-locale)
 
 $(INSTALL-SUPPORTED-LOCALE-FILES): install-locales-dir
-	@flags="-c --no-archive"; \
+	@flags="-c --no-archive --no-hard-links"; \
 	$(build-one-locale)
 
 tst-setlocale-ENV = LC_ALL=ja_JP.EUC-JP
-- 
2.19.1

-- 
Cheers,
Carlos.

Re: [PATCHv2] Add --no-hard-links option to localedef (Bug 23923)

[Florian Weimer]

* Carlos O'Donell:

> On 11/26/18 11:58 AM, Joseph Myers wrote:
>> On Mon, 26 Nov 2018, Carlos O'Donell wrote:
>> 
>>> If the downstream distro wants to post-process the hardlinks then
>>> the time spent in localedef looking up sibling directories and
>>> processing hardlinks is wasted effort.
>> 
>> Do you have figures for the time involved?
>
> On a fast SSD the -j1 locale build and install of SUPPORTED locales
> is 3% faster, or for me roughly ~10s on a:
> "make localedata/install-locale-files DESTDIR=..." iteration.
>
> The option itself ensures that no hard links are present and that may
> make the logic of the post-install hardlink creation phase simpler.
> So there is more than just performance to consider.

The real performance win comes from the ability to use parallel make and
still get fully deterministic results.

Thanks,
Florian

Re: [PATCHv2] Add --no-hard-links option to localedef (Bug 23923)

[Carlos O'Donell]

On 11/26/18 2:26 PM, Florian Weimer wrote:
> * Carlos O'Donell:
> 
>> On 11/26/18 11:58 AM, Joseph Myers wrote:
>>> On Mon, 26 Nov 2018, Carlos O'Donell wrote:
>>>
>>>> If the downstream distro wants to post-process the hardlinks then
>>>> the time spent in localedef looking up sibling directories and
>>>> processing hardlinks is wasted effort.
>>>
>>> Do you have figures for the time involved?
>>
>> On a fast SSD the -j1 locale build and install of SUPPORTED locales
>> is 3% faster, or for me roughly ~10s on a:
>> "make localedata/install-locale-files DESTDIR=..." iteration.
>>
>> The option itself ensures that no hard links are present and that may
>> make the logic of the post-install hardlink creation phase simpler.
>> So there is more than just performance to consider.
> 
> The real performance win comes from the ability to use parallel make and
> still get fully deterministic results.

If you are OK with v2 then I'll give it a few days for others to comment
and then commit. In v2 I switch the 'make localedata/install-locale-files'
to use --no-hard-links as the default distribution way to install the
files deterministically regardless of build paralleism.

-- 
Cheers,
Carlos.

Re: [PATCHv2] Add --no-hard-links option to localedef (Bug 23923)

[Carlos O'Donell]

On 11/26/18 2:33 PM, Carlos O'Donell wrote:
> On 11/26/18 2:26 PM, Florian Weimer wrote:
>> * Carlos O'Donell:
>>
>>> On 11/26/18 11:58 AM, Joseph Myers wrote:
>>>> On Mon, 26 Nov 2018, Carlos O'Donell wrote:
>>>>
>>>>> If the downstream distro wants to post-process the hardlinks then
>>>>> the time spent in localedef looking up sibling directories and
>>>>> processing hardlinks is wasted effort.
>>>>
>>>> Do you have figures for the time involved?
>>>
>>> On a fast SSD the -j1 locale build and install of SUPPORTED locales
>>> is 3% faster, or for me roughly ~10s on a:
>>> "make localedata/install-locale-files DESTDIR=..." iteration.
>>>
>>> The option itself ensures that no hard links are present and that may
>>> make the logic of the post-install hardlink creation phase simpler.
>>> So there is more than just performance to consider.
>>
>> The real performance win comes from the ability to use parallel make and
>> still get fully deterministic results.
> 
> If you are OK with v2 then I'll give it a few days for others to comment
> and then commit. In v2 I switch the 'make localedata/install-locale-files'
> to use --no-hard-links as the default distribution way to install the
> files deterministically regardless of build paralleism.
> 

OK, I've pushed v2, and this alters 'make localedata/install-locale-files'

I have also added a note in the "Packaging Changes" for distribution maintainers
to read regarding the change in the convenience target:

https://sourceware.org/glibc/wiki/Release/2.29#Localedata_installation_without_hard_links

-- 
Cheers,
Carlos.