On Wed, Aug 02, 2023 at 11:48:18AM -0400, Stefan Berger wrote: > When a kernel dump is present then restrict the high memory regions to > avoid allocating memory where the kernel dump resides. Use the > ibm,kernel-dump node under /rtas to determine whether a kernel dump exists > and up to which limit grub can use available memory. Set the > upper_mem_limit to the size of the kernel dump section of type > 'REAL_MODE_REGION' and therefore only allow grub's memory usage for high > addresses from RMO_ADDR_MAX to 'upper_mem_limit'. This means that grub can > use high memory in the range of RMO_ADDR_MAX (768MB) to upper_mem_limit and > the kernel-dump memory regions above 'upper_mem_limit' remain untouched. > This change has no effect on memory allocations below 'linux_rmo_save' > (typically at 640MB). > > Also, fall back to allocating below rmo_linux_save in case the chunk of > memory there would be larger than the chunk of memory above RMO_ADDR_MAX. > This can for example occur if a free memory area is found starting at 300MB > extending up to 1GB but a kernel dump is located at 768MB and therefore > does not allow the allocation of the high memory area but requiring to use > the chunk starting at 300MB to avoid an unnecessary out-of-memory > condition. > > Signed-off-by: Stefan Berger <stef...@linux.ibm.com> > Reviewed-by: Hari Bathini <hbath...@linux.ibm.com>
Please do not add RBs of folks who has not reply to an email publicly with their own RB. I will take this patch with Hari's RB when he confirms it here. > Cc: Pavithra Prakash <pavra...@in.ibm.com> > Cc: Michael Ellerman <m...@ellerman.id.au> > Cc: Carolyn Scherrer <cpsch...@us.ibm.com> > Cc: Mahesh Salgaonkar <mah...@linux.ibm.com> > Cc: Sourabh Jain <sourabhj...@linux.ibm.com> ... otherwise Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com>... Daniel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
