On Wed, 4 Nov 2020 08:55:11 -0500 Hsin-Hui Wu <hsinhuiwu@xxxxxxxxx> wrote: > > With a machine with 3 TB (more than 2 TB memory). If you use vmalloc to > > allocate > 2 TB memory, the array_size below will be overflowed. > > How was this observed? > > Is there any know userspace operation which causes the kernel to try to > vmalloc such a large hunk of memory? > > [Frank] The Dell PowerEdge R740/R940 can have up to 3TB/6TB memory. > installed. Our application requires reserve consecutive memory in the kernel > space and protected from userspace programs. Did this require custom kernel changes? If not, precisely which system calls were used to cause this allocation attempt? > ---------------------------------------------------------------------------------------------------- > OK, thanks. Against current mainline your proposed change would look > like this, yes? > > [Frank] Yes. This will support up to less than 16 TB. If you want to support > more than 16 TB, we need to expand nr_pages to unsigned long as > Matthew pointed out. > > Will it be possible to add this to kernel 3.10.0-957.27.2.el7.x86_64? That is up to Red Hat to decide.
