Re: [Mesa-dev] [PATCH 1/4] util/disk_cache: rename mesa cache dir and introduce cache versioning

[Emil Velikov]

Hi Tim,

A couple of small suggestions which should be applicable, regardless
of the current discussion.

On 15 August 2017 at 00:26, Timothy Arceri  wrote:
> Steam is already analysing cache items, unfortunatly we did not
s/unfortunatly/unfortunately/


> -   check_directories_created(CACHE_TEST_TMP "/xdg-cache-home/mesa");
> +   check_directories_created(CACHE_TEST_TMP
> + "/xdg-cache-home/mesa_shader_cache");
>
Replace "mesa_shader_cache" instances with the define?

At some misc later stage:
 - introduce defines for xdg-cache-home and mesa-glsl-cache-dir


> +#define CACHE_DIR_NAME "mesa_shader_cache"
> +
> +/* The cache version should be bumped whenever a change is made to the
> + * structure of cache entries or the index. This will give any 3rd party
> + * applications reading the cache entries a chance to adjust to the changes.
> + */
I don't have strong opinion on each of the following, although I think
it's important to have them documented:
 - is the version checked in internally
 - is forward/backward compatibility expected

> +#define CACHE_VERSION 1
> +


> -   memcpy(cache->driver_keys_blob, timestamp, ts_size);
> -   memcpy(cache->driver_keys_blob + ts_size, gpu_name, gpu_name_size);
> -   memcpy(cache->driver_keys_blob + ts_size + gpu_name_size, _size,
> -  ptr_size_size);
> -   memcpy(cache->driver_keys_blob + ts_size + gpu_name_size + ptr_size_size,
> +   memcpy(cache->driver_keys_blob, _version, cv_size);
> +   memcpy(cache->driver_keys_blob + cv_size, timestamp, ts_size);
> +   memcpy(cache->driver_keys_blob + cv_size + ts_size, gpu_name,
> +  gpu_name_size);
> +   memcpy(cache->driver_keys_blob + cv_size + ts_size + gpu_name_size,
> +  _size, ptr_size_size);
> +   memcpy(cache->driver_keys_blob + cv_size + ts_size +
> +  gpu_name_size + ptr_size_size,
>_flags, driver_flags_size);
>
In case you're not a huge fan of the memcpy(ptr + a + b + ... + z,
...) bits something like the following should help.

// One could also kill off _src_size
#define FOO_CPY(_dst, _src, _src_size) { \
   memcpy(_dst, _src, _src_size); \
   _dst += _src_size; \
} while (0)


-Emil
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Re: [Mesa-dev] [PATCH 1/4] util/disk_cache: rename mesa cache dir and introduce cache versioning

[Timothy Arceri]

On 18/08/17 23:05, Nicolai Hähnle wrote:

On 18.08.2017 13:45, Timothy Arceri wrote:



On 18/08/17 21:02, Nicolai Hähnle wrote:

On 15.08.2017 01:26, Timothy Arceri wrote:

Steam is already analysing cache items, unfortunatly we did not
introduce a versioning mechanism for identifying structural changes
to cache entries earlier so the only way to do so is to rename the
cache directory.

Since we are renaming it we take the opportunity to give the directory
a more meaningful name.

Adding a version field to the header of cache entries will help us to
avoid having to rename the directory in future. Please note this is
versioning for the internal structure of the entries as defined in
disk_cache.{c,h} as opposed to the structure of the data provided to
the disk cache by the GLSL compiler and the various driver backends.


If the version is intended to reflect the disk cache-internal 
structure of files, shouldn't you check the version when loading a file?


Not really we have been relying on cache collisions being improbable 
up to this point. We can check but it doesn't add a great deal of 
value, the version is also unlikely to change very often.


Okay, so the version is basically intended as a version of the header. 
That's fine.


Still, consider what happens in a theoretical update where the header 
format is changed. Then loading files of the old version will likely 
fail mysteriously either during inflating the payload or during the CRC 
check, because Mesa will calculate the header size incorrectly. That's 
not ideal.


But that can only happen if there is a collision, I did mention in the 
commit messages that this extra info can indeed be used to help 
safeguard against collisions if we want to go down that road. Crashing 
loading the header is probably better than the alternative which could 
include system lockups if and invalid program is passed to the gpu. The 
cache entries should be safe enough because the build time is part of 
the sha.


Anyway it can easily be added as an improvement, I don't think it should 
block this series.




BTW, it may be useful to put the total header size in the file as well, 
so we can just skip it quickly at load, since Mesa doesn't use it. (And 
probably won't use it -- checking those GLSL source hashes shouldn't be 
necessary.)


If we are going to bother with collision avoidance i.e checking the 
header version as you are suggesting above, then it would actually be 
much more useful to check those shas as well.






Also, what about the index file? Shouldn't it get the version as well?


The index can be rebuilt from the from the cache entries once this 
series lands. I don't think we need to bother with it.


I suppose a corrupt index doesn't really hurt (other than perhaps 
forcing a delayed shader compile), so I guess it's fine.


Cheers,
Nicolai






Cheers,
Nicolai



---
  src/compiler/glsl/tests/cache_test.c |  6 --
  src/util/disk_cache.c| 37 
+---

  2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/compiler/glsl/tests/cache_test.c 
b/src/compiler/glsl/tests/cache_test.c

index af1b66fb3d..aa779e3985 100644
--- a/src/compiler/glsl/tests/cache_test.c
+++ b/src/compiler/glsl/tests/cache_test.c
@@ -178,38 +178,40 @@ test_disk_cache_create(void)
 /* Test with XDG_CACHE_HOME set */
 setenv("XDG_CACHE_HOME", CACHE_TEST_TMP "/xdg-cache-home", 1);
 cache = disk_cache_create("test", "make_check", 0);
 expect_null(cache, "disk_cache_create with XDG_CACHE_HOME set 
with"

 "a non-existing parent directory");
 mkdir(CACHE_TEST_TMP, 0755);
 cache = disk_cache_create("test", "make_check", 0);
 expect_non_null(cache, "disk_cache_create with XDG_CACHE_HOME 
set");

-   check_directories_created(CACHE_TEST_TMP "/xdg-cache-home/mesa");
+   check_directories_created(CACHE_TEST_TMP
+ "/xdg-cache-home/mesa_shader_cache");
 disk_cache_destroy(cache);
 /* Test with MESA_GLSL_CACHE_DIR set */
 err = rmrf_local(CACHE_TEST_TMP);
 expect_equal(err, 0, "Removing " CACHE_TEST_TMP);
 setenv("MESA_GLSL_CACHE_DIR", CACHE_TEST_TMP 
"/mesa-glsl-cache-dir", 1);

 cache = disk_cache_create("test", "make_check", 0);
 expect_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR 
set with"

 "a non-existing parent directory");
 mkdir(CACHE_TEST_TMP, 0755);
 cache = disk_cache_create("test", "make_check", 0);
 expect_non_null(cache, "disk_cache_create with 
MESA_GLSL_CACHE_DIR set");
-   check_directories_created(CACHE_TEST_TMP 
"/mesa-glsl-cache-dir/mesa");

+   check_directories_created(CACHE_TEST_TMP
+ 
"/mesa-glsl-cache-dir/mesa_shader_cache");

 disk_cache_destroy(cache);
  }
  static bool
  does_cache_contain(struct disk_cache *cache, const cache_key key)
  {
 void *result;
 result = disk_cache_get(cache, key, NULL);
diff --git 

Re: [Mesa-dev] [PATCH 1/4] util/disk_cache: rename mesa cache dir and introduce cache versioning

[Nicolai Hähnle]

On 18.08.2017 13:45, Timothy Arceri wrote:



On 18/08/17 21:02, Nicolai Hähnle wrote:

On 15.08.2017 01:26, Timothy Arceri wrote:

Steam is already analysing cache items, unfortunatly we did not
introduce a versioning mechanism for identifying structural changes
to cache entries earlier so the only way to do so is to rename the
cache directory.

Since we are renaming it we take the opportunity to give the directory
a more meaningful name.

Adding a version field to the header of cache entries will help us to
avoid having to rename the directory in future. Please note this is
versioning for the internal structure of the entries as defined in
disk_cache.{c,h} as opposed to the structure of the data provided to
the disk cache by the GLSL compiler and the various driver backends.


If the version is intended to reflect the disk cache-internal 
structure of files, shouldn't you check the version when loading a file?


Not really we have been relying on cache collisions being improbable up 
to this point. We can check but it doesn't add a great deal of value, 
the version is also unlikely to change very often.


Okay, so the version is basically intended as a version of the header. 
That's fine.


Still, consider what happens in a theoretical update where the header 
format is changed. Then loading files of the old version will likely 
fail mysteriously either during inflating the payload or during the CRC 
check, because Mesa will calculate the header size incorrectly. That's 
not ideal.


BTW, it may be useful to put the total header size in the file as well, 
so we can just skip it quickly at load, since Mesa doesn't use it. (And 
probably won't use it -- checking those GLSL source hashes shouldn't be 
necessary.)




Also, what about the index file? Shouldn't it get the version as well?


The index can be rebuilt from the from the cache entries once this 
series lands. I don't think we need to bother with it.


I suppose a corrupt index doesn't really hurt (other than perhaps 
forcing a delayed shader compile), so I guess it's fine.


Cheers,
Nicolai






Cheers,
Nicolai



---
  src/compiler/glsl/tests/cache_test.c |  6 --
  src/util/disk_cache.c| 37 
+---

  2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/compiler/glsl/tests/cache_test.c 
b/src/compiler/glsl/tests/cache_test.c

index af1b66fb3d..aa779e3985 100644
--- a/src/compiler/glsl/tests/cache_test.c
+++ b/src/compiler/glsl/tests/cache_test.c
@@ -178,38 +178,40 @@ test_disk_cache_create(void)
 /* Test with XDG_CACHE_HOME set */
 setenv("XDG_CACHE_HOME", CACHE_TEST_TMP "/xdg-cache-home", 1);
 cache = disk_cache_create("test", "make_check", 0);
 expect_null(cache, "disk_cache_create with XDG_CACHE_HOME set with"
 "a non-existing parent directory");
 mkdir(CACHE_TEST_TMP, 0755);
 cache = disk_cache_create("test", "make_check", 0);
 expect_non_null(cache, "disk_cache_create with XDG_CACHE_HOME 
set");

-   check_directories_created(CACHE_TEST_TMP "/xdg-cache-home/mesa");
+   check_directories_created(CACHE_TEST_TMP
+ "/xdg-cache-home/mesa_shader_cache");
 disk_cache_destroy(cache);
 /* Test with MESA_GLSL_CACHE_DIR set */
 err = rmrf_local(CACHE_TEST_TMP);
 expect_equal(err, 0, "Removing " CACHE_TEST_TMP);
 setenv("MESA_GLSL_CACHE_DIR", CACHE_TEST_TMP 
"/mesa-glsl-cache-dir", 1);

 cache = disk_cache_create("test", "make_check", 0);
 expect_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR 
set with"

 "a non-existing parent directory");
 mkdir(CACHE_TEST_TMP, 0755);
 cache = disk_cache_create("test", "make_check", 0);
 expect_non_null(cache, "disk_cache_create with 
MESA_GLSL_CACHE_DIR set");
-   check_directories_created(CACHE_TEST_TMP 
"/mesa-glsl-cache-dir/mesa");

+   check_directories_created(CACHE_TEST_TMP
+ "/mesa-glsl-cache-dir/mesa_shader_cache");
 disk_cache_destroy(cache);
  }
  static bool
  does_cache_contain(struct disk_cache *cache, const cache_key key)
  {
 void *result;
 result = disk_cache_get(cache, key, NULL);
diff --git a/src/util/disk_cache.c b/src/util/disk_cache.c
index b2229874e0..283856b15c 100644
--- a/src/util/disk_cache.c
+++ b/src/util/disk_cache.c
@@ -51,20 +51,28 @@
  /* Number of bits to mask off from a cache key to get an index. */
  #define CACHE_INDEX_KEY_BITS 16
  /* Mask for computing an index from a key. */
  #define CACHE_INDEX_KEY_MASK ((1 << CACHE_INDEX_KEY_BITS) - 1)
  /* The number of keys that can be stored in the index. */
  #define CACHE_INDEX_MAX_KEYS (1 << CACHE_INDEX_KEY_BITS)
+#define CACHE_DIR_NAME "mesa_shader_cache"
+
+/* The cache version should be bumped whenever a change is made to the
+ * structure of cache entries or the index. This will give any 3rd 
party
+ * applications reading the cache entries a chance to adjust to the 
changes.

+ */
+#define 

Re: [Mesa-dev] [PATCH 1/4] util/disk_cache: rename mesa cache dir and introduce cache versioning

[Timothy Arceri]

On 18/08/17 21:02, Nicolai Hähnle wrote:

On 15.08.2017 01:26, Timothy Arceri wrote:

Steam is already analysing cache items, unfortunatly we did not
introduce a versioning mechanism for identifying structural changes
to cache entries earlier so the only way to do so is to rename the
cache directory.

Since we are renaming it we take the opportunity to give the directory
a more meaningful name.

Adding a version field to the header of cache entries will help us to
avoid having to rename the directory in future. Please note this is
versioning for the internal structure of the entries as defined in
disk_cache.{c,h} as opposed to the structure of the data provided to
the disk cache by the GLSL compiler and the various driver backends.


If the version is intended to reflect the disk cache-internal structure 
of files, shouldn't you check the version when loading a file?


Not really we have been relying on cache collisions being improbable up 
to this point. We can check but it doesn't add a great deal of value, 
the version is also unlikely to change very often.




Also, what about the index file? Shouldn't it get the version as well?


The index can be rebuilt from the from the cache entries once this 
series lands. I don't think we need to bother with it.




Cheers,
Nicolai



---
  src/compiler/glsl/tests/cache_test.c |  6 --
  src/util/disk_cache.c| 37 
+---

  2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/compiler/glsl/tests/cache_test.c 
b/src/compiler/glsl/tests/cache_test.c

index af1b66fb3d..aa779e3985 100644
--- a/src/compiler/glsl/tests/cache_test.c
+++ b/src/compiler/glsl/tests/cache_test.c
@@ -178,38 +178,40 @@ test_disk_cache_create(void)
 /* Test with XDG_CACHE_HOME set */
 setenv("XDG_CACHE_HOME", CACHE_TEST_TMP "/xdg-cache-home", 1);
 cache = disk_cache_create("test", "make_check", 0);
 expect_null(cache, "disk_cache_create with XDG_CACHE_HOME set with"
 "a non-existing parent directory");
 mkdir(CACHE_TEST_TMP, 0755);
 cache = disk_cache_create("test", "make_check", 0);
 expect_non_null(cache, "disk_cache_create with XDG_CACHE_HOME set");
-   check_directories_created(CACHE_TEST_TMP "/xdg-cache-home/mesa");
+   check_directories_created(CACHE_TEST_TMP
+ "/xdg-cache-home/mesa_shader_cache");
 disk_cache_destroy(cache);
 /* Test with MESA_GLSL_CACHE_DIR set */
 err = rmrf_local(CACHE_TEST_TMP);
 expect_equal(err, 0, "Removing " CACHE_TEST_TMP);
 setenv("MESA_GLSL_CACHE_DIR", CACHE_TEST_TMP 
"/mesa-glsl-cache-dir", 1);

 cache = disk_cache_create("test", "make_check", 0);
 expect_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR 
set with"

 "a non-existing parent directory");
 mkdir(CACHE_TEST_TMP, 0755);
 cache = disk_cache_create("test", "make_check", 0);
 expect_non_null(cache, "disk_cache_create with 
MESA_GLSL_CACHE_DIR set");
-   check_directories_created(CACHE_TEST_TMP 
"/mesa-glsl-cache-dir/mesa");

+   check_directories_created(CACHE_TEST_TMP
+ "/mesa-glsl-cache-dir/mesa_shader_cache");
 disk_cache_destroy(cache);
  }
  static bool
  does_cache_contain(struct disk_cache *cache, const cache_key key)
  {
 void *result;
 result = disk_cache_get(cache, key, NULL);
diff --git a/src/util/disk_cache.c b/src/util/disk_cache.c
index b2229874e0..283856b15c 100644
--- a/src/util/disk_cache.c
+++ b/src/util/disk_cache.c
@@ -51,20 +51,28 @@
  /* Number of bits to mask off from a cache key to get an index. */
  #define CACHE_INDEX_KEY_BITS 16
  /* Mask for computing an index from a key. */
  #define CACHE_INDEX_KEY_MASK ((1 << CACHE_INDEX_KEY_BITS) - 1)
  /* The number of keys that can be stored in the index. */
  #define CACHE_INDEX_MAX_KEYS (1 << CACHE_INDEX_KEY_BITS)
+#define CACHE_DIR_NAME "mesa_shader_cache"
+
+/* The cache version should be bumped whenever a change is made to the
+ * structure of cache entries or the index. This will give any 3rd party
+ * applications reading the cache entries a chance to adjust to the 
changes.

+ */
+#define CACHE_VERSION 1
+
  struct disk_cache {
 /* The path to the cache directory. */
 char *path;
 /* Thread queue for compressing and writing cache entries to disk */
 struct util_queue cache_queue;
 /* Seed for rand, which is used to pick a random directory */
 uint64_t seed_xorshift128plus[2];
@@ -181,41 +189,41 @@ disk_cache_create(const char *gpu_name, const 
char *timestamp,

 if (local == NULL)
goto fail;
 /* At user request, disable shader cache entirely. */
 if (getenv("MESA_GLSL_CACHE_DISABLE"))
goto fail;
 /* Determine path for cache based on the first defined name as 
follows:

  *
  *   $MESA_GLSL_CACHE_DIR
-*   $XDG_CACHE_HOME/mesa
-*   /.cache/mesa
+*   $XDG_CACHE_HOME/mesa_shader_cache
+*   

Re: [Mesa-dev] [PATCH 1/4] util/disk_cache: rename mesa cache dir and introduce cache versioning

[Nicolai Hähnle]

On 15.08.2017 01:26, Timothy Arceri wrote:

Steam is already analysing cache items, unfortunatly we did not
introduce a versioning mechanism for identifying structural changes
to cache entries earlier so the only way to do so is to rename the
cache directory.

Since we are renaming it we take the opportunity to give the directory
a more meaningful name.

Adding a version field to the header of cache entries will help us to
avoid having to rename the directory in future. Please note this is
versioning for the internal structure of the entries as defined in
disk_cache.{c,h} as opposed to the structure of the data provided to
the disk cache by the GLSL compiler and the various driver backends.


If the version is intended to reflect the disk cache-internal structure 
of files, shouldn't you check the version when loading a file?


Also, what about the index file? Shouldn't it get the version as well?

Cheers,
Nicolai



---
  src/compiler/glsl/tests/cache_test.c |  6 --
  src/util/disk_cache.c| 37 +---
  2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/compiler/glsl/tests/cache_test.c 
b/src/compiler/glsl/tests/cache_test.c
index af1b66fb3d..aa779e3985 100644
--- a/src/compiler/glsl/tests/cache_test.c
+++ b/src/compiler/glsl/tests/cache_test.c
@@ -178,38 +178,40 @@ test_disk_cache_create(void)
 /* Test with XDG_CACHE_HOME set */
 setenv("XDG_CACHE_HOME", CACHE_TEST_TMP "/xdg-cache-home", 1);
 cache = disk_cache_create("test", "make_check", 0);
 expect_null(cache, "disk_cache_create with XDG_CACHE_HOME set with"
 "a non-existing parent directory");
  
 mkdir(CACHE_TEST_TMP, 0755);

 cache = disk_cache_create("test", "make_check", 0);
 expect_non_null(cache, "disk_cache_create with XDG_CACHE_HOME set");
  
-   check_directories_created(CACHE_TEST_TMP "/xdg-cache-home/mesa");

+   check_directories_created(CACHE_TEST_TMP
+ "/xdg-cache-home/mesa_shader_cache");
  
 disk_cache_destroy(cache);
  
 /* Test with MESA_GLSL_CACHE_DIR set */

 err = rmrf_local(CACHE_TEST_TMP);
 expect_equal(err, 0, "Removing " CACHE_TEST_TMP);
  
 setenv("MESA_GLSL_CACHE_DIR", CACHE_TEST_TMP "/mesa-glsl-cache-dir", 1);

 cache = disk_cache_create("test", "make_check", 0);
 expect_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR set with"
 "a non-existing parent directory");
  
 mkdir(CACHE_TEST_TMP, 0755);

 cache = disk_cache_create("test", "make_check", 0);
 expect_non_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR set");
  
-   check_directories_created(CACHE_TEST_TMP "/mesa-glsl-cache-dir/mesa");

+   check_directories_created(CACHE_TEST_TMP
+ "/mesa-glsl-cache-dir/mesa_shader_cache");
  
 disk_cache_destroy(cache);

  }
  
  static bool

  does_cache_contain(struct disk_cache *cache, const cache_key key)
  {
 void *result;
  
 result = disk_cache_get(cache, key, NULL);

diff --git a/src/util/disk_cache.c b/src/util/disk_cache.c
index b2229874e0..283856b15c 100644
--- a/src/util/disk_cache.c
+++ b/src/util/disk_cache.c
@@ -51,20 +51,28 @@
  
  /* Number of bits to mask off from a cache key to get an index. */

  #define CACHE_INDEX_KEY_BITS 16
  
  /* Mask for computing an index from a key. */

  #define CACHE_INDEX_KEY_MASK ((1 << CACHE_INDEX_KEY_BITS) - 1)
  
  /* The number of keys that can be stored in the index. */

  #define CACHE_INDEX_MAX_KEYS (1 << CACHE_INDEX_KEY_BITS)
  
+#define CACHE_DIR_NAME "mesa_shader_cache"

+
+/* The cache version should be bumped whenever a change is made to the
+ * structure of cache entries or the index. This will give any 3rd party
+ * applications reading the cache entries a chance to adjust to the changes.
+ */
+#define CACHE_VERSION 1
+
  struct disk_cache {
 /* The path to the cache directory. */
 char *path;
  
 /* Thread queue for compressing and writing cache entries to disk */

 struct util_queue cache_queue;
  
 /* Seed for rand, which is used to pick a random directory */

 uint64_t seed_xorshift128plus[2];
  
@@ -181,41 +189,41 @@ disk_cache_create(const char *gpu_name, const char *timestamp,

 if (local == NULL)
goto fail;
  
 /* At user request, disable shader cache entirely. */

 if (getenv("MESA_GLSL_CACHE_DISABLE"))
goto fail;
  
 /* Determine path for cache based on the first defined name as follows:

  *
  *   $MESA_GLSL_CACHE_DIR
-*   $XDG_CACHE_HOME/mesa
-*   /.cache/mesa
+*   $XDG_CACHE_HOME/mesa_shader_cache
+*   /.cache/mesa_shader_cache
  */
 path = getenv("MESA_GLSL_CACHE_DIR");
 if (path) {
if (mkdir_if_needed(path) == -1)
   goto fail;
  
-  path = concatenate_and_mkdir(local, path, "mesa");

+  path = concatenate_and_mkdir(local, path, CACHE_DIR_NAME);
if (path == NULL)
   goto fail;

Re: [Mesa-dev] [PATCH 1/4] util/disk_cache: rename mesa cache dir and introduce cache versioning

[Dieter Nützel]

For the series:

Tested-by: Dieter Nützel 

on RX580

with Steam (wine-staging / Nine and CSMT)

Dieter

Am 15.08.2017 01:26, schrieb Timothy Arceri:

Steam is already analysing cache items, unfortunatly we did not
introduce a versioning mechanism for identifying structural changes
to cache entries earlier so the only way to do so is to rename the
cache directory.

Since we are renaming it we take the opportunity to give the directory
a more meaningful name.

Adding a version field to the header of cache entries will help us to
avoid having to rename the directory in future. Please note this is
versioning for the internal structure of the entries as defined in
disk_cache.{c,h} as opposed to the structure of the data provided to
the disk cache by the GLSL compiler and the various driver backends.
---
 src/compiler/glsl/tests/cache_test.c |  6 --
 src/util/disk_cache.c| 37 
+---

 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/compiler/glsl/tests/cache_test.c
b/src/compiler/glsl/tests/cache_test.c
index af1b66fb3d..aa779e3985 100644
--- a/src/compiler/glsl/tests/cache_test.c
+++ b/src/compiler/glsl/tests/cache_test.c
@@ -178,38 +178,40 @@ test_disk_cache_create(void)
/* Test with XDG_CACHE_HOME set */
setenv("XDG_CACHE_HOME", CACHE_TEST_TMP "/xdg-cache-home", 1);
cache = disk_cache_create("test", "make_check", 0);
expect_null(cache, "disk_cache_create with XDG_CACHE_HOME set with"
"a non-existing parent directory");

mkdir(CACHE_TEST_TMP, 0755);
cache = disk_cache_create("test", "make_check", 0);
expect_non_null(cache, "disk_cache_create with XDG_CACHE_HOME 
set");


-   check_directories_created(CACHE_TEST_TMP "/xdg-cache-home/mesa");
+   check_directories_created(CACHE_TEST_TMP
+ "/xdg-cache-home/mesa_shader_cache");

disk_cache_destroy(cache);

/* Test with MESA_GLSL_CACHE_DIR set */
err = rmrf_local(CACHE_TEST_TMP);
expect_equal(err, 0, "Removing " CACHE_TEST_TMP);

setenv("MESA_GLSL_CACHE_DIR", CACHE_TEST_TMP 
"/mesa-glsl-cache-dir", 1);

cache = disk_cache_create("test", "make_check", 0);
expect_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR set 
with"

"a non-existing parent directory");

mkdir(CACHE_TEST_TMP, 0755);
cache = disk_cache_create("test", "make_check", 0);
expect_non_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR 
set");


-   check_directories_created(CACHE_TEST_TMP 
"/mesa-glsl-cache-dir/mesa");

+   check_directories_created(CACHE_TEST_TMP
+ 
"/mesa-glsl-cache-dir/mesa_shader_cache");


disk_cache_destroy(cache);
 }

 static bool
 does_cache_contain(struct disk_cache *cache, const cache_key key)
 {
void *result;

result = disk_cache_get(cache, key, NULL);
diff --git a/src/util/disk_cache.c b/src/util/disk_cache.c
index b2229874e0..283856b15c 100644
--- a/src/util/disk_cache.c
+++ b/src/util/disk_cache.c
@@ -51,20 +51,28 @@

 /* Number of bits to mask off from a cache key to get an index. */
 #define CACHE_INDEX_KEY_BITS 16

 /* Mask for computing an index from a key. */
 #define CACHE_INDEX_KEY_MASK ((1 << CACHE_INDEX_KEY_BITS) - 1)

 /* The number of keys that can be stored in the index. */
 #define CACHE_INDEX_MAX_KEYS (1 << CACHE_INDEX_KEY_BITS)

+#define CACHE_DIR_NAME "mesa_shader_cache"
+
+/* The cache version should be bumped whenever a change is made to the
+ * structure of cache entries or the index. This will give any 3rd 
party
+ * applications reading the cache entries a chance to adjust to the 
changes.

+ */
+#define CACHE_VERSION 1
+
 struct disk_cache {
/* The path to the cache directory. */
char *path;

/* Thread queue for compressing and writing cache entries to disk 
*/

struct util_queue cache_queue;

/* Seed for rand, which is used to pick a random directory */
uint64_t seed_xorshift128plus[2];

@@ -181,41 +189,41 @@ disk_cache_create(const char *gpu_name, const
char *timestamp,
if (local == NULL)
   goto fail;

/* At user request, disable shader cache entirely. */
if (getenv("MESA_GLSL_CACHE_DISABLE"))
   goto fail;

/* Determine path for cache based on the first defined name as 
follows:

 *
 *   $MESA_GLSL_CACHE_DIR
-*   $XDG_CACHE_HOME/mesa
-*   /.cache/mesa
+*   $XDG_CACHE_HOME/mesa_shader_cache
+*   /.cache/mesa_shader_cache
 */
path = getenv("MESA_GLSL_CACHE_DIR");
if (path) {
   if (mkdir_if_needed(path) == -1)
  goto fail;

-  path = concatenate_and_mkdir(local, path, "mesa");
+  path = concatenate_and_mkdir(local, path, CACHE_DIR_NAME);
   if (path == NULL)
  goto fail;
}

if (path == NULL) {
   char *xdg_cache_home = getenv("XDG_CACHE_HOME");

   if (xdg_cache_home) {
  if (mkdir_if_needed(xdg_cache_home) == -1)
 goto fail;

-