>If nothing else, then when the first huge block is detected >give a warning: > huge block detected (%lu bytes); consider adjusting --freelist-vol Note that in this case, the problem is not the free list. The default value of the free list is quite small (20Mb). See my other mail(s) for a description of why this "realloc" program is failing under Valgrind (and the patch improving Valgrind).
However, there are real problems with the free list when huge blocks are allocated and freed by the client: there is in fact no (good) protection anymore by memcheck against dangling pointer pointing to big memory blocks, as these have a lot of chance to be re-used directly after free (as they do not go to the free list). I am even suspecting that free-ing a huge block (> freelist-vol) will flush the whole of freelist-vol, so in effect removing all the memcheck dangling pointer protection for all the recently allocated and freed small blocks. I was intending to work on improving the free-list behaviour, but I think it is first needed to have https://bugs.kde.org/show_bug.cgi?id=250101 fixed. (and as always, my current priority is gdbserver patch :). Philippe ____ This message and any files transmitted with it are legally privileged and intended for the sole use of the individual(s) or entity to whom they are addressed. If you are not the intended recipient, please notify the sender by reply and delete the message and any attachments from your system. Any unauthorised use or disclosure of the content of this message is strictly prohibited and may be unlawful. Nothing in this e-mail message amounts to a contractual or legal commitment on the part of EUROCONTROL, unless it is confirmed by appropriately signed hard copy. Any views expressed in this message are those of the sender. ------------------------------------------------------------------------------ Create and publish websites with WebMatrix Use the most popular FREE web apps or write code yourself; WebMatrix provides all the features you need to develop and publish your website. http://p.sf.net/sfu/ms-webmatrix-sf _______________________________________________ Valgrind-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/valgrind-users
