Cache is not invalidated after change of content

To be more clear, I have minimum cache lifetime set to "none", if I understand it correctly that should mean invalidate cache_page immediatly if content is changed

I use http://drupal.org/node/152983 for manual clearing and it works ok, but ofcourse it's not solution to my problem

Hmmmm.... How this kind of bug could exist after so many people use memcache module ? If page cache is not flushing at all that means site is almost not working :(
These moments just make me think how much of importance proper software testing is. Guess all you guys use cache and cache_page tables in one memcache bin so you don't notice this problem (in that case 'cache_page' is flushed together with 'cache' )

So you say, after update of content function cache_clear_all() is called without $table argument
It seems so, for example from the end of node_save function in core

  // Clear the cache so an anonymous poster can see the node being added or updated.
  cache_clear_all();
}

from original cache.inc:

function cache_clear_all($cid = NULL, $table = NULL, $wildcard = FALSE) {
  global $user;

  if (!isset($cid) && !isset($table)) {
    cache_clear_all(NULL, 'cache_page');
    return;
  }

Guess we should follow same rule then and flush cache_page if both $cid and $table are null

chx, what version of memcache module you made your patch against ?
It wouldn't apply anyway, because there is no such line

$bin = empty($table) ? 'cache' : $table;

You messed it a bit :)
I guess error comes from using variable $bin in $table argument check. There is line

$bin = empty($table) ? 'cache_page' : $table;

but it's not working because we dont use $bin anymore in the function. Proper patch should include checking like this
if (!isset($cid) && !isset($table)) and setting $table variable to 'cache_page' instead of $bin variable

It seems cache_clear_all() needs serious rework, cause comments like this don't make any sense

// don't do anything if cid is unset. this matches the default drupal behavior...

It actually DOESN'T match default drupal behavior when cache_clear_all() is called without arguments to flush cache.
This is awful.

I guess we should check if $table and $cid are null then set $table to 'cache_page' and call dmemcache_flush($table) ( it isn't called now, because $cid is null and we "don't do anything if cid is unset" :P )

The following change fixed bug for me. Please test it too.

-  $bin = empty($table) ? 'cache_page' : $table;
+  if (!isset($cid) && !isset($table)) {
+    dmemcache_flush('cache_page');
+    return;
+  }

But I guess function code needs major rework to make code more clean ( and to remove nonsense comments :P )

chx, did you read my comments ? Your patch will not work because $cid is NULL too and dmemcache_flush() won't run.
Also this patch will not apply too ( same as above )

Funny thing is, in memcache.db.inc there is correct code that handles flushes:

  if (!isset($cid) && !isset($table)) {
    cache_clear_all('*', 'cache_page', TRUE);
    return;
  }

but somehow this code didn't make it to memcache.inc ... :)