dcr0@harvey.gte.com (David Robbins) (04/10/91)
I am running some programs that make heavy use of shared memory. At times, one or the other of the programs dies with a "Memory Fault". Using sdb, I can see that the memory fault occurs on the first access to a page of shared memory. The address is, however, a valid address in the shared memory region, and indeed sdb can happily read and write the address. Furthermore, if I continue the program's execution, it will go on as if nothing bad had happened (until the next time it hits one of these memory faults). This seems to happen randomly, because most of the time when the program visits a page of shared memory for the first time, nothing goes wrong at all. So, I am rather mystified -- if no problem occurs most of the time, and if sdb and subsequent execution of the program can read and write the page at the address where the memory fault occurred, what exactly is going on here? Have any of you A/UX gurus out there seen anything like this? Is there a situation in A/UX where a page fault is somehow not caught? Is there something I should be doing in my program to make sure that the page is handled properly? Any suggestions, thoughts, advice, flames, or what have you would be appreciated. -- Dave Robbins GTE Laboratories Incorporated drobbins@bunny.gte.com 40 Sylvan Rd. ...!harvard!bunny!drobbins Waltham, MA 02254 CYA: I speak only for myself; GTE may disagree with what I say.