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| author | Christian Biesinger <cbiesinger@google.com> | 2019-11-18 16:37:31 -0600 |
|---|---|---|
| committer | Christian Biesinger <cbiesinger@google.com> | 2019-11-22 11:42:41 -0600 |
| commit | f8bab2d61d84b4e122ca667c4e458cd2ca29e3b6 (patch) | |
| tree | 05b3a9dc41b308d031b3ed2b084a0f52fecf2001 | |
| parent | 85e7588dc4b191326f90d4e2358566d9cc14242a (diff) | |
| download | gdb-f8bab2d61d84b4e122ca667c4e458cd2ca29e3b6.zip gdb-f8bab2d61d84b4e122ca667c4e458cd2ca29e3b6.tar.gz gdb-f8bab2d61d84b4e122ca667c4e458cd2ca29e3b6.tar.bz2 | |
Create a correctly-sized demangled names hashtable
If we have a minsym count, we know the demangled names hashtable will
be at least that big. So use that count to size it, so we don't
have to resize/rehash it as much.
This is a 6% improvement in minsym loading time.
2019-11-22 Christian Biesinger <cbiesinger@google.com>
* symtab.c (create_demangled_names_hash): Use per_bfd->
minimal_symbol_count for computing the initial size, if greater
than our default size.
Change-Id: I1f074d38e1d90af58705ec852f90c84cc034cd2e
| -rw-r--r-- | gdb/ChangeLog | 6 | ||||
| -rw-r--r-- | gdb/symtab.c | 14 |
2 files changed, 18 insertions, 2 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 93258c3..838262e 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2019-11-22 Christian Biesinger <cbiesinger@google.com> + + * symtab.c (create_demangled_names_hash): Use per_bfd-> + minimal_symbol_count for computing the initial size, if greater + than our default size. + 2019-11-22 Tom de Vries <tdevries@suse.de> * contrib/words.sh: Improve words extraction. diff --git a/gdb/symtab.c b/gdb/symtab.c index 0064800..6affdef 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -770,10 +770,20 @@ create_demangled_names_hash (struct objfile_per_bfd_storage *per_bfd) /* Choose 256 as the starting size of the hash table, somewhat arbitrarily. The hash table code will round this up to the next prime number. Choosing a much larger table size wastes memory, and saves only about - 1% in symbol reading. */ + 1% in symbol reading. However, if the minsym count is already + initialized (e.g. because symbol name setting was deferred to + a background thread) we can initialize the hashtable with a count + based on that, because we will almost certainly have at least that + many entries. If we have a nonzero number but less than 256, + we still stay with 256 to have some space for psymbols, etc. */ + + /* htab will expand the table when it is 3/4th full, so we account for that + here. +2 to round up. */ + int minsym_based_count = (per_bfd->minimal_symbol_count + 2) / 3 * 4; + int count = std::max (per_bfd->minimal_symbol_count, minsym_based_count); per_bfd->demangled_names_hash.reset (htab_create_alloc - (256, hash_demangled_name_entry, eq_demangled_name_entry, + (count, hash_demangled_name_entry, eq_demangled_name_entry, free_demangled_name_entry, xcalloc, xfree)); } |