Messages in this thread Patch in this message |  | | From | Jim Cromie <> | Subject | [RFC PATCH v6 31/34] dyndbg: detect repeated site recs in add_module | Date | Sat, 29 May 2021 14:00:26 -0600 |
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Since the 1st patch in this series, which partitioned into structs _ddebug & _ddebug_site while leaving lineno in _ddebug, we have had chunks of repeating site records; every pr_debug in a function has identical site data.
To avoid reliance on the redundant data, we need: 0. ._map field (added HEAD~1) 1. detection of repeating sites.
In ddebug_add_module(), alter the index initialization loop to recognize the 1st record in each block of repeats, remember it in "j", and use it to ._map all the pr_debugs in that block. To find the block starts, we can just look for a new .function in each row.
This gives us, for each function; 1st used row, 2nd-Nth unused rows. To actually reclaim useful memory chunks, we will have to pack the site records up towards the header.
Heres what booting with dynamic_debug.verbose=3 will show:
1st 3 builtin modules: - cols 3,4 row 1 - shows +1 due to previous head64 - cols 2,4 - shows repeat detection working
rcu: Hierarchical SRCU implementation. dyndbg: add-module: head64.1 sites dyndbg: skip header head64 dyndbg: add-module: main.6 sites Callback from call_rcu_tasks_trace() invoked. dyndbg: 0 0 1 1 main.run_init_process.1358 dyndbg: 1 0 2 1 main.run_init_process.1356 dyndbg: 2 0 3 1 main.run_init_process.1355 dyndbg: 3 0 4 1 main.run_init_process.1353 dyndbg: 4 4 5 5 main.initcall_blacklisted.1142 dyndbg: 5 5 6 6 main.initcall_blacklist.1103 dyndbg: 6 debug prints in module main (in 3 functions) dyndbg: add-module: initramfs.1 sites dyndbg: 0 0 7 7 initramfs.unpack_to_rootfs.496 dyndbg: 1 debug prints in module initramfs (in 1 functions) dyndbg: add-module: ibs.3 sites dyndbg: 0 0 8 8 ibs.force_ibs_eilvt_setup.926 dyndbg: 1 1 9 9 ibs.setup_ibs_ctl.897 dyndbg: 2 1 10 9 ibs.setup_ibs_ctl.890 dyndbg: 3 debug prints in module ibs (in 2 functions)
for a loaded module: - row 0000 - is the header (function==module) - lineno is garbage - cols 2,4 - show repeat detect - 9 functions - over by 1, due to counting the header
dyndbg: add-module: intel_rapl_common.13 sites dyndbg: 0 0 0 0 intel_rapl_common.intel_rapl_common.16928 dyndbg: 1 1 1 1 intel_rapl_common.rapl_remove_package.1279 dyndbg: 2 2 2 2 intel_rapl_common.rapl_detect_domains.1245 dyndbg: 3 2 3 2 intel_rapl_common.rapl_detect_domains.1242 dyndbg: 4 4 4 4 intel_rapl_common.rapl_package_register_powercap.1159 dyndbg: 5 4 5 4 intel_rapl_common.rapl_package_register_powercap.1145 dyndbg: 6 4 6 4 intel_rapl_common.rapl_package_register_powercap.1114 dyndbg: 7 4 7 4 intel_rapl_common.rapl_package_register_powercap.1108 dyndbg: 8 8 8 8 intel_rapl_common.rapl_update_domain_data.1083 dyndbg: 9 9 9 9 intel_rapl_common.rapl_check_unit_atom.824 dyndbg: 10 10 10 10 intel_rapl_common.rapl_check_unit_core.796 dyndbg: 11 11 11 11 intel_rapl_common.rapl_read_data_raw.722 dyndbg: 12 12 12 12 intel_rapl_common.contraint_to_pl.303 dyndbg: 13 debug prints in module intel_rapl_common (in 9 functions) Signed-off-by: Jim Cromie <jim.cromie@gmail.com> --- lib/dynamic_debug.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 524303a04462..e12538640b51 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -1073,7 +1073,7 @@ static int __ddebug_add_module(struct _ddebug *tab, struct _ddebug_site *sites, { struct ddebug_table *dt; union _ddebug_header *dh = (union _ddebug_header *) &tab[0]; - int i; + int i, j, ct; v3pr_info("add-module: %s.%d sites\n", modname, numdbgs); @@ -1107,10 +1107,22 @@ static int __ddebug_add_module(struct _ddebug *tab, struct _ddebug_site *sites, dt->ddebugs = tab; dt->sites = sites; - for (i = 0; i < numdbgs; i++) { - tab[i]._back = base + i; - tab[i]._map = base + i; - v3pr_info(" %d %d %d %s.%s.%d\n", i, tab[i]._back, tab[i]._map, + /* + * Since sites don't have lineno (thats in struct _ddebug), + * all pr_debugs in a function have identical site data. So + * we watch for repeats on site.function, and reuse the index + * of the 1st site record in a repeating block. + */ + for (ct = i = j = 0; i < numdbgs; i++) { + tab[i]._back = base + i; /* index back to header */ + + if (sites[i].function != sites[j].function) { + j = i; /* remember 1st row with new fn */ + ct++; + } + tab[i]._map = base + j; + + v3pr_info(" %d %d %d %d %s.%s.%d\n", i, j, tab[i]._back, tab[i]._map, modname, sites[i].function, tab[i].lineno); } @@ -1118,7 +1130,9 @@ static int __ddebug_add_module(struct _ddebug *tab, struct _ddebug_site *sites, list_add(&dt->link, &ddebug_tables); mutex_unlock(&ddebug_lock); - v2pr_info("%3u debug prints in module %s\n", numdbgs, modname); + v2pr_info("%3u debug prints in module %s (in %d functions)\n", + numdbgs, modname, ++ct); + return 0; } -- 2.31.1
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