Re: [Success] XEmacs 21.5-b20 "cilantro" (+CVS-20050311) i586-pc-win32

AA> Marcus, could you please give the setting of AA> KKCC_BT_STACK_SIZE AA> some more thought. Definitely: I'll move to dynamic allocation of the backtrace stack, because the stack size depends on dynamically allocated data. In your crash, the benchmark creates lists with a few million elements, which leads to a backtrace stack containing a few million entries. To cover this special case statically with a big value for KKCC_BT_STACK_SIZE does not make sense: it would be a waste of memory for most applications, whereas it would still be easy to create an application which again exceedes the limit. The only way to catch everything (despite of full memory exhaustion, of course) is to allocate the stack dynamically. I should have realized this earlier; I'll work on that next week. AA> We need to find a way for ERROR_CHECK_GC to not CAUSE crashes, else it AA> is doomed. This is not a general problem of ERROR_CHECK_GC (actually, in your tests this crash should only be triggered by DEBUG_XEMACS). The problem is, that I chose a static data structure (I chose a static data structure because it is fast and it is already used in pdump's backtrace. But estimating a working backtrace size limit at dump time is easier than during run time). AA> Which parts of KKCC error checking is actually enabled by AA> --error-checking This checks that marked data really is a Lisp_Object, and that not already freed data is marked. It does not use any additional memory, but it is more time intensive. AA> and which by AA> --debug The KKCC backtrace is the only debug mechanism for KKCC. Before the backtrace there was no debugging aid. It consumes a lot of additional memory (as you experienced) and a little bit more time (some assignments and the time it takes to manage a stack, which will be higher for a dynamically allocated stack). AA> While --debug should not slow down XEmacs, --error-checking is known AA> and specified to do so. KKCC follows these specifications. -- Marcus