Hi, Currenty linux kernel allocates memory at the boot time for crash kernel booted using kexec system call in kernel crash. It will be very useful if we can allocate memory in run time. It is possible to allocate memory for crash kernel at the boot time using CMA (Contiguous Memory Allocator). CMA is capable of allocating big chunk of memory. At the boot time we will create one (if only low memory is used) or two (if we use both high and low memory) CMA areas of size given in "crashkernel" boot time command line parameter. Then the user can allocate or free memory from those CMA areas using "/sys/kernel/kexec_crash_size" sysfs entry. I am attaching a prototype patch with the mail. I have made the patch against kernel version v4.4.11. Please give your opinions. -------------- next part -------------- A non-text attachment was scrubbed... Name: cma.patch Type: text/x-patch Size: 7874 bytes Desc: not available URL: <http://lists.infradead.org/pipermail/kexec/attachments/20160620/aaf44fdb/attachment.bin>
