> On Thu, Sep 03, 2015 at 11:24:47AM +0900, Yongtaek Lee wrote: > > default value of vmalloc_min was set 0xf0000000 for ARM by commit > > 0536bdf3. But actually vmalloc_min is 0xef800000 not 0xf0000000. > > > > VMALLOC_END - (240 << 20) - VMALLOC_OFFSET) > > 0xff000000 - 0x0f000000 - 0x00800000 = 0xef800000 > > > > In case of 768MB ram without CONFIG_HIGHMEM=y, last 8MB could not be > > allocated. Kernel log also print out warning message as below. > > "Truncating RAM at 80000000-afffffff to -af7fffff (vmalloc region overlap)." > > > > Although it could be solved by state "vmalloc=size" in cmdline but i think > > it would be better to change default value to 232 from 240. > > > > Signed-off-by: Yongtaek Lee <ytk....@samsung.com> > > I fail to see what the problem is here. You're adjusting the size of the > vmalloc space to accomodate the size of RAM you have. That's not a bug.
I will explain more about problem. It could happened with 768MB RAM device and CONFIG_HIGHMEN is not set. "vmalloc=size" also not stated so that default value of vmalloc_min will be used to calculate lowmem end address. before applying patch. [ 0.000000] [0: swapper: 0] [c0] Truncating RAM at 80000000-afffffff to -af7fffff (vmalloc region overlap). [ 0.000000] [0: swapper: 0] [c0] Memory: 106MB 652MB = 758MB total [ 0.000000] [0: swapper: 0] [c0] Memory: 669892k/669892k available, 108348k reserved, 0K highmem [ 0.000000] [0: swapper: 0] [c0] Virtual kernel memory layout: [ 0.000000] [0: swapper: 0] vector : 0xffff0000 - 0xffff1000 ( 4 kB) [ 0.000000] [0: swapper: 0] fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) [ 0.000000] [0: swapper: 0] vmalloc : 0xf0000000 - 0xff000000 ( 240 MB) [ 0.000000] [0: swapper: 0] lowmem : 0xc0000000 - 0xef800000 ( 760 MB) [ 0.000000] [0: swapper: 0] modules : 0xbf000000 - 0xc0000000 ( 16 MB) [ 0.000000] [0: swapper: 0] .text : 0xc0008000 - 0xc09bbee0 (9936 kB) [ 0.000000] [0: swapper: 0] .init : 0xc09bc000 - 0xc0a2b740 ( 446 kB) [ 0.000000] [0: swapper: 0] .data : 0xc0a2c000 - 0xc0ac4088 ( 609 kB) [ 0.000000] [0: swapper: 0] .bss : 0xc0ac4088 - 0xc0d3e7b4 (2538 kB) after applying patch. [ 0.000000] [0: swapper: 0] [c0] Memory: 106MB 660MB = 766MB total [ 0.000000] [0: swapper: 0] [c0] Memory: 678004k/678004k available, 108428k reserved, 0K highmem [ 0.000000] [0: swapper: 0] [c0] Virtual kernel memory layout: [ 0.000000] [0: swapper: 0] vector : 0xffff0000 - 0xffff1000 ( 4 kB) [ 0.000000] [0: swapper: 0] fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) [ 0.000000] [0: swapper: 0] vmalloc : 0xf0800000 - 0xff000000 ( 232 MB) [ 0.000000] [0: swapper: 0] lowmem : 0xc0000000 - 0xf0000000 ( 768 MB) [ 0.000000] [0: swapper: 0] modules : 0xbf000000 - 0xc0000000 ( 16 MB) [ 0.000000] [0: swapper: 0] .text : 0xc0008000 - 0xc09bbee0 (9936 kB) [ 0.000000] [0: swapper: 0] .init : 0xc09bc000 - 0xc0a2b740 ( 446 kB) [ 0.000000] [0: swapper: 0] .data : 0xc0a2c000 - 0xc0ac4088 ( 609 kB) [ 0.000000] [0: swapper: 0] .bss : 0xc0ac4088 - 0xc0d3e7b4 (2538 kB) As i know "vmalloc=size" is not mandatory so that i think default value of vmalloc_min is wrong. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
