dm: core: Add a command to show driver model statistics

This command shows the memory used by driver model along with various
hints as to what it might be if some 'core' tags were moved to use the
tag list instead of a core (i.e. always-there) pointer.

This may help with future work to reduce memory usage.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/cmd/dm.c b/cmd/dm.c
index 0c7554a1b1df0b463f547217f6d512ab2c32a9da..eb40f0865fe0776bcad9d3bb55793de94223865c 100644 (file)
--- a/cmd/dm.c
+++ b/cmd/dm.c
@@ -8,6 +8,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <dm/root.h>
 #include <dm/util.h>
 
 static int do_dm_dump_driver_compat(struct cmd_tbl *cmdtp, int flag, int argc,
@@ -34,6 +35,19 @@ static int do_dm_dump_drivers(struct cmd_tbl *cmdtp, int flag, int argc,
        return 0;
 }
 
+#if CONFIG_IS_ENABLED(DM_STATS)
+static int do_dm_dump_mem(struct cmd_tbl *cmdtp, int flag, int argc,
+                         char *const argv[])
+{
+       struct dm_stats mem;
+
+       dm_get_mem(&mem);
+       dm_dump_mem(&mem);
+
+       return 0;
+}
+#endif /* DM_STATS */
+
 static int do_dm_dump_static_driver_info(struct cmd_tbl *cmdtp, int flag,
                                         int argc, char * const argv[])
 {
@@ -58,11 +72,20 @@ static int do_dm_dump_uclass(struct cmd_tbl *cmdtp, int flag, int argc,
        return 0;
 }
 
+#if CONFIG_IS_ENABLED(DM_STATS)
+#define DM_MEM_HELP    "dm mem           Provide a summary of memory usage\n"
+#define DM_MEM         U_BOOT_SUBCMD_MKENT(mem, 1, 1, do_dm_dump_mem),
+#else
+#define DM_MEM_HELP
+#define DM_MEM
+#endif
+
 #if CONFIG_IS_ENABLED(SYS_LONGHELP)
 static char dm_help_text[] =
        "compat        Dump list of drivers with compatibility strings\n"
        "dm devres        Dump list of device resources for each device\n"
        "dm drivers       Dump list of drivers with uclass and instances\n"
+       DM_MEM_HELP
        "dm static        Dump list of drivers with static platform data\n"
        "dn tree          Dump tree of driver model devices ('*' = activated)\n"
        "dm uclass        Dump list of instances for each uclass"
@@ -73,6 +96,7 @@ U_BOOT_CMD_WITH_SUBCMDS(dm, "Driver model low level access", dm_help_text,
        U_BOOT_SUBCMD_MKENT(compat, 1, 1, do_dm_dump_driver_compat),
        U_BOOT_SUBCMD_MKENT(devres, 1, 1, do_dm_dump_devres),
        U_BOOT_SUBCMD_MKENT(drivers, 1, 1, do_dm_dump_drivers),
+       DM_MEM
        U_BOOT_SUBCMD_MKENT(static, 1, 1, do_dm_dump_static_driver_info),
        U_BOOT_SUBCMD_MKENT(tree, 1, 1, do_dm_dump_tree),
        U_BOOT_SUBCMD_MKENT(uclass, 1, 1, do_dm_dump_uclass));

diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig
index 9b9a7148a1a48457c9d0996a7461f484ff41221e..97dc699e969a72d118d4a3ce6cd9115792765377 100644 (file)
--- a/drivers/core/Kconfig
+++ b/drivers/core/Kconfig
@@ -75,6 +75,17 @@ config DM_DEBUG
        help
          Say Y here if you want to compile in debug messages in DM core.
 
+config DM_STATS
+       bool "Collect and show driver model stats"
+       depends on DM
+       default y if SANDBOX
+       help
+         Enable this to collect and display memory statistics about driver
+         model. This can help to figure out where all the memory is going and
+         to find optimisations.
+
+         To display the memory stats, use the 'dm mem' command.
+
 config DM_DEVICE_REMOVE
        bool "Support device removal"
        depends on DM

diff --git a/drivers/core/dump.c b/drivers/core/dump.c
index e434fe04728b0d79ab733fa2281534e8ce19e044..1c1f7e4d3082b73ce7d6c2154a6b7642d9611b13 100644 (file)
--- a/drivers/core/dump.c
+++ b/drivers/core/dump.c
@@ -172,3 +172,76 @@ void dm_dump_static_driver_info(void)
        for (entry = drv; entry != drv + n_ents; entry++)
                printf("%-25.25s %p\n", entry->name, entry->plat);
 }
+
+void dm_dump_mem(struct dm_stats *stats)
+{
+       int total, total_delta;
+       int i;
+
+       /* Support SPL printf() */
+       printf("Struct sizes: udevice %x, driver %x, uclass %x, uc_driver %x\n",
+              (int)sizeof(struct udevice), (int)sizeof(struct driver),
+              (int)sizeof(struct uclass), (int)sizeof(struct uclass_driver));
+       printf("Memory: device %x:%x, device names %x, uclass %x:%x\n",
+              stats->dev_count, stats->dev_size, stats->dev_name_size,
+              stats->uc_count, stats->uc_size);
+       printf("\n");
+       printf("%-15s  %5s  %5s  %5s  %5s  %5s\n", "Attached type", "Count",
+              "Size", "Cur", "Tags", "Save");
+       printf("%-15s  %5s  %5s  %5s  %5s  %5s\n", "---------------", "-----",
+              "-----", "-----", "-----", "-----");
+       total_delta = 0;
+       for (i = 0; i < DM_TAG_ATTACH_COUNT; i++) {
+               int cur_size, new_size, delta;
+
+               cur_size = stats->dev_count * sizeof(struct udevice);
+               new_size = stats->dev_count * (sizeof(struct udevice) -
+                       sizeof(void *));
+               /*
+                * Let's assume we can fit each dmtag_node into 32 bits. We can
+                * limit the 'tiny tags' feature to SPL with
+                * CONFIG_SPL_SYS_MALLOC_F_LEN <= 64KB, so needing 14 bits to
+                * point to anything in that region (with 4-byte alignment).
+                * So:
+                *    4 bits for tag
+                *    14 bits for offset of dev
+                *    14 bits for offset of data
+                */
+               new_size += stats->attach_count[i] * sizeof(u32);
+               delta = cur_size - new_size;
+               total_delta += delta;
+               printf("%-16s %5x %6x %6x %6x %6x (%d)\n", tag_get_name(i),
+                      stats->attach_count[i], stats->attach_size[i],
+                      cur_size, new_size, delta > 0 ? delta : 0, delta);
+       }
+       printf("%-16s %5x %6x\n", "uclass", stats->uc_attach_count,
+              stats->uc_attach_size);
+       printf("%-16s %5x %6x  %5s  %5s  %6x (%d)\n", "Attached total",
+              stats->attach_count_total + stats->uc_attach_count,
+              stats->attach_size_total + stats->uc_attach_size, "", "",
+              total_delta > 0 ? total_delta : 0, total_delta);
+       printf("%-16s %5x %6x\n", "tags", stats->tag_count, stats->tag_size);
+       printf("\n");
+       printf("Total size: %x (%d)\n", stats->total_size, stats->total_size);
+       printf("\n");
+
+       total = stats->total_size;
+       total -= total_delta;
+       printf("With tags:       %x (%d)\n", total, total);
+
+       /* Use singly linked lists in struct udevice (3 nodes in each) */
+       total -= sizeof(void *) * 3 * stats->dev_count;
+       printf("- singly-linked: %x (%d)\n", total, total);
+
+       /* Use an index into the struct_driver list instead of a pointer */
+       total = total + stats->dev_count * (1 - sizeof(void *));
+       printf("- driver index:  %x (%d)\n", total, total);
+
+       /* Same with the uclass */
+       total = total + stats->dev_count * (1 - sizeof(void *));
+       printf("- uclass index:  %x (%d)\n", total, total);
+
+       /* Drop the device name */
+       printf("Drop device name (not SRAM): %x (%d)\n", stats->dev_name_size,
+              stats->dev_name_size);
+}

diff --git a/drivers/core/tag.c b/drivers/core/tag.c
index 2961725b658070cc018fce61bc8d7ab855910a5d..a3c5cb7e57cc8c0f32bffab4fb763b55e1d1dc7a 100644 (file)
--- a/drivers/core/tag.c
+++ b/drivers/core/tag.c
@@ -16,6 +16,24 @@ struct udevice;
 
 DECLARE_GLOBAL_DATA_PTR;
 
+static const char *const tag_name[] = {
+       [DM_TAG_PLAT]           = "plat",
+       [DM_TAG_PARENT_PLAT]    = "parent_plat",
+       [DM_TAG_UC_PLAT]        = "uclass_plat",
+
+       [DM_TAG_PRIV]           = "priv",
+       [DM_TAG_PARENT_PRIV]    = "parent_priv",
+       [DM_TAG_UC_PRIV]        = "uclass_priv",
+       [DM_TAG_DRIVER_DATA]    = "driver_data",
+
+       [DM_TAG_EFI]            = "efi",
+};
+
+const char *tag_get_name(enum dm_tag_t tag)
+{
+       return tag_name[tag];
+}
+
 int dev_tag_set_ptr(struct udevice *dev, enum dm_tag_t tag, void *ptr)
 {
        struct dmtag_node *node;

diff --git a/include/dm/root.h b/include/dm/root.h
index 382f83c7f5b71a7a1927e710fcb4bab192b03bd5..b2f30a842f515d70982ec8af7599a86d12002176 100644 (file)
--- a/include/dm/root.h
+++ b/include/dm/root.h
@@ -182,7 +182,7 @@ void dm_get_stats(int *device_countp, int *uclass_countp);
 /**
  * dm_get_mem() - Get stats on memory usage in driver model
  *
- * @mem: Place to put the information
+ * @stats: Place to put the information
  */
 void dm_get_mem(struct dm_stats *stats);
 

diff --git a/include/dm/tag.h b/include/dm/tag.h
index 1ea3c9f7af381772d4ed1c1a5de4d2e523bde1cd..745088ffcff464ea73931d140292bb1fa423fca0 100644 (file)
--- a/include/dm/tag.h
+++ b/include/dm/tag.h
@@ -129,4 +129,12 @@ int dev_tag_del_all(struct udevice *dev);
  */
 void dev_tag_collect_stats(struct dm_stats *stats);
 
+/**
+ * tag_get_name() - Get the name of a tag
+ *
+ * @tag: Tag to look up, which must be valid
+ * Returns: Name of tag
+ */
+const char *tag_get_name(enum dm_tag_t tag);
+
 #endif /* _DM_TAG_H */

diff --git a/include/dm/util.h b/include/dm/util.h
index c52daa87ef310c6c7842463a4e0f15151da8de6a..e10c6060ce000b5c1c1269b415a2fd69a0e635e7 100644 (file)
--- a/include/dm/util.h
+++ b/include/dm/util.h
@@ -6,6 +6,8 @@
 #ifndef __DM_UTIL_H
 #define __DM_UTIL_H
 
+struct dm_stats;
+
 #if CONFIG_IS_ENABLED(DM_WARN)
 #define dm_warn(fmt...) log(LOGC_DM, LOGL_WARNING, ##fmt)
 #else
@@ -48,6 +50,13 @@ void dm_dump_driver_compat(void);
 /* Dump out a list of drivers with static platform data */
 void dm_dump_static_driver_info(void);
 
+/**
+ * dm_dump_mem() - Dump stats on memory usage in driver model
+ *
+ * @mem: Stats to dump
+ */
+void dm_dump_mem(struct dm_stats *stats);
+
 #if CONFIG_IS_ENABLED(OF_PLATDATA_INST) && CONFIG_IS_ENABLED(READ_ONLY)
 void *dm_priv_to_rw(void *priv);
 #else