Commit 9e4c9d0a authored by Raymond Toy's avatar Raymond Toy
Browse files

Reduce maximum heap size for Linux. 

According to the message from Chisheng Huang on cmucl-help,
2016-02-27, 32-bit Ubuntu 11.10 (in VirtualBox) cannot use the full
heap space.  There's something already allocated at address 0xb7b82000,
so limit the max heap to address 0xb7b80000, for a total of 1530 MB
instead of 1632 MB.

(It would be nice to be able to detect this somehow.)
parent 8d6a01fb

src/lisp/x86-validate-linux.h

+12 −3
Original line number Diff line number Diff line
@@ -22,12 +22,21 @@ 
 *	0x38000000->0x40000000  128M Control stack growing down.

 *	0x40000000->0x48000000  128M Reserved for shared libraries.

 *      0x58000000->0x58100000   16M Foreign Linkage Table

 *	0x58100000->0xBE000000 1631M Dynamic Space.

 *      0xBFFF0000->0xC0000000       Unknown Linux mapping

 *	0x58100000->0xB7B00000 1530M Dynamic Space.

 *      0xB7B82000->0xC0000000       Unknown Linux mapping, including stack

 *

 *     

 *      (Note: 0x58000000 allows us to run on a Linux system on an AMD

 *      x86-64.  Hence we have a gap of unused memory starting at

 *      0x48000000.)

 *

 * It appears as if the actual upper limit depends on the particular

 * Linux distribution.  Ubuntu 11.10 (32-bit) appears to have

 * something mapped at 0xb78b2000, so we can't allocate the dynamic

 * space past that.  That results in a max heap size of 1530 MB.

 * However, Fedora 22 ther appears to be nothing mapped there.  In

 * fact it appears to be free all the way to 0xf7c1b000.  That would

 * allow a heap of size 2555 MB.

 */



#define READ_ONLY_SPACE_START   (SpaceStart_TargetReadOnly)
@@ -48,7 +57,7 @@ 
#define DYNAMIC_0_SPACE_START	(SpaceStart_TargetDynamic)



#ifdef GENCGC

#define DYNAMIC_SPACE_SIZE	(0x66000000)	/* 1.632GB */

#define DYNAMIC_SPACE_SIZE	(0x5FA00000)	/* 1.530GB */

#else

#define DYNAMIC_SPACE_SIZE	(0x04000000)	/* 64MB */

#endif