[Monotone-devel] slow update/status on NFS

[Benoît Dejean]

Hello,

I have a repository of 2000 files over NFS. update and status are very
slow. I have strace/truss it and found a lot of stat calls. I think this
just kill performance on a network filesystem. When doing a status, each
file is stat'ed 4 times in a row. The following patch saves 2 calls. The
1 remaining is triggered by an assert_path_is_file in calculate_ident. I
don't know if it's good, but on my workspace, it saves a lot of stat
calls. It goes from ~8000 to ~4000. This almost saves 15% of the time to
do a status. On a local filesystem, this makes no difference at all.
(If it worths it, please let me push :)
-- 
Benoît Dejean
GNOME http://www.gnomefr.org/
LibGTop http://directory.fsf.org/libgtop.html

#
# old_revision [5af0ed3151ef2c1ad92a4b353ffd7b86dcd6a4d3]
#
# patch "file_io.cc"
#  from [1edaa600f491b3cddb7628be8f0ab5d218971815]
#    to [60011f929084283e969ee8a5b9d591d43edb86af]
# 
# patch "file_io.hh"
#  from [a9c4eac0ba8fd78a612dc775dcef76424769e2be]
#    to [2c7717337282a9f47e587ae7095b07d11b602f9c]
# 
# patch "work.cc"
#  from [9b78a7cb064436d0eed809eaa14c46b548b46096]
#    to [776774635a7ac315d0f22c8386145569e5813cdb]
#
============================================================
--- file_io.cc  1edaa600f491b3cddb7628be8f0ab5d218971815
+++ file_io.cc  60011f929084283e969ee8a5b9d591d43edb86af
@@ -556,7 +556,13 @@ ident_existing_file(file_path const & p,
 bool
 ident_existing_file(file_path const & p, file_id & ident)
 {
-  switch (get_path_status(p))
+  return ident_existing_file(p, ident, get_path_status(p));
+}
+
+bool
+ident_existing_file(file_path const & p, file_id & ident, path::status status)
+{
+  switch (status)
     {
     case path::nonexistent:
       return false;
============================================================
--- file_io.hh  a9c4eac0ba8fd78a612dc775dcef76424769e2be
+++ file_io.hh  2c7717337282a9f47e587ae7095b07d11b602f9c
@@ -13,6 +13,7 @@
 #include "vocab.hh"
 #include "paths.hh"
 #include "sanity.hh"
+#include "platform.hh"
 
 // this layer deals with talking to the filesystem, loading and saving
 // files, walking trees, etc.
@@ -116,6 +117,8 @@ bool ident_existing_file(file_path const
 
 
 bool ident_existing_file(file_path const & p, file_id & ident);
+bool ident_existing_file(file_path const & p, file_id & ident, path::status 
status);
+
 void calculate_ident(file_path const & file,
                      hexenc<id> & ident);
 
============================================================
--- work.cc     9b78a7cb064436d0eed809eaa14c46b548b46096
+++ work.cc     776774635a7ac315d0f22c8386145569e5813cdb
@@ -1179,14 +1179,16 @@ workspace::update_current_roster_from_fi
       ros.get_name(nid, sp);
       file_path fp(sp);
 
+      const path::status status(get_path_status(fp));
+
       if (is_dir_t(node))
         {
-          if (!path_exists(fp))
+          if (status == path::nonexistent)
             {
               W(F("missing directory '%s'") % (fp));
               missing_items++;
             }
-          else if (!directory_exists(fp))
+          else if (status != path::directory)
             {
               W(F("not a directory '%s'") % (fp));
               missing_items++;
@@ -1199,19 +1201,19 @@ workspace::update_current_roster_from_fi
           if (inodeprint_unchanged(ipm, fp))
             continue;
 
-          if (!path_exists(fp))
+          if (status == path::nonexistent)
             {
               W(F("missing file '%s'") % (fp));
               missing_items++;
             }
-          else if (!file_exists(fp))
+          else if (status != path::file)
             {
               W(F("not a file '%s'") % (fp));
               missing_items++;
             }
 
           file_t file = downcast_to_file_t(node);
-          ident_existing_file(fp, file->content);
+          ident_existing_file(fp, file->content, status);
         }
 
     }

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