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1.1     ! root        1: 
        !             2: HATARI MEMORY USAGE
        !             3: 
        !             4: Here are some stats on Hatari 0.81 memory usage (on Linux) and what
        !             5: could be done to decrease it for embedded devices.
        !             6: 
        !             7: 
        !             8: First the binary size from "size ./hatari":
        !             9:    text    data      bss       dec
        !            10: 1382406   10712 18255264  19648382
        !            11: 
        !            12: I.e. the binary size is 1.3MB, it has 10KB of pre-defined arrays and
        !            13: 18MB of non-initialized fixed size arrays.  The names of the arrays
        !            14: are listed at the bottom, but STRam is the one taking 16MB.
        !            15: 
        !            16: Happily Hatari doesn't dirty (zero) all of STRam, just first 4MB
        !            17: (accessible as ST ram) and 2MB at the top (used as IO-memory,
        !            18: TOS and cartridge memory).  In next Hatari version Hatari will
        !            19: zero only part of the ST ram that user has configured
        !            20: (e.g. 0.5MB instead of 4MB -> 3.5MB private memory save).
        !            21: 
        !            22: 
        !            23: When I profiled Hatari with Valgrind (valgrind.kde.org) Massif plugin,
        !            24: it tells that Hatari malloc()s about 3MB of memory. The allocations
        !            25: and how to make them smaller for embedded devices (no generic way
        !            26: unfortunately) are:
        !            27: 
        !            28: * In includes/vdi.h set MAX_VDI_WIDTH and MAX_VDI_HEIGHT from 1024 and
        !            29:   768 to 640 and 400 respectively. This decrease memory usage from 1.5MB
        !            30:   to 0.5MB (btw. for page flipping Allocation 2*2 framebuffers).
        !            31:   - Change list of VDI modes in Hatari dialog accordingly
        !            32: 
        !            33: * Do not load bigfont in gui-sdl/sdlgui.c, especially if the device
        !            34:   screen is smaller than VGA.  Both fonts together take about 1/3 MB.
        !            35: 
        !            36: * Change uncompressed file read to use mmap() instead, currently
        !            37:   memory is allocated for the whole disk image before reading it.
        !            38:   - With normal DD floppy image Hatari would use that amount which
        !            39:     might be acceptable, but with e.g. 2MB disk needed for running
        !            40:     Wolf3D v0.8, mmap() sounds much better
        !            41:   - For compressed disk images memory needs to be allocated for
        !            42:     uncompressed image data, i.e. there we cannot save memory.
        !            43: 
        !            44: * Check whether the m86k instruction table could be made smaller:
        !            45:         #include "uae-cpu/readcpu.h"
        !            46:         printf("%d -> %d\n", sizeof(struct instr), sizeof(struct instr) * 65536);
        !            47:   On x86 it's slightly over 1MB.
        !            48: 
        !            49: You can also Massif Hatari yourself, its allocation calltrees
        !            50: are very short, so it's easy to find these from the produced
        !            51: PostScript graph and txt/html calltree listing.
        !            52: 
        !            53: 
        !            54: From /proc/sysvipc/shm one can see how much shared memory Hatari/libSDL
        !            55: has allocated and that it shares it with the X server:
        !            56: - >100KB in lowrez
        !            57: - ~200KB in lowrez with borders
        !            58: - ~500KB in monochrome or zoomed lowrez
        !            59: - >800KB in zoomed lowrez with borders
        !            60: I don't think these could be made smaller from the code. Besides
        !            61: user can just use a the smaller Hatari screen mode.
        !            62: 
        !            63: According to Xrestop, Hatari doesn't keep any Pixmap resources
        !            64: at the X server side.
        !            65: 
        !            66: 
        !            67: Finally when looking at the Hatari process with "pmap", you can
        !            68: see that the binaries Hatari links don't use so much private
        !            69: (writable) memory:
        !            70:     map <Hatari PID>|grep /|grep w
        !            71: 
        !            72: Rest of the 30MB Hatari VMSIZE you see in "top" (about 10MB), goes to
        !            73: shared library code (their .text sections with "r-x" rights) Hatari
        !            74: links.  That is memory mapped read-only / read in on-demand / pagable
        !            75: back to disk so it's not so much of a problem.
        !            76: 
        !            77: 
        !            78: Unmodified Hatari runs on (Linux) systems having about 20MB of free
        !            79: memory (e.g. according to /proc/meminfo free+buffers+cached fields).
        !            80: Using low-rez without borders nor zooming, setting emulated ST memory
        !            81: amount to <=1MB, limiting the VDI screen size and removing bigfont
        !            82: (discussed with Massif findings above) should enable running Hatari
        !            83: well on a system with only 10MB free memory, if it's otherwise fast
        !            84: enough.
        !            85: 
        !            86: 
        !            87:        - Eero Tamminen
        !            88: 
        !            89: To see the objects in the binary BSS section, get the datadump script
        !            90: from here:
        !            91:      http://live.gnome.org/MemoryReduction_2fTools
        !            92: 
        !            93: Compile Hatari without stripping, and use:
        !            94:      datadump.py -n -s .bss ./hatari
        !            95: 
        !            96: As a result you see these array variables (larger ones):
        !            97: 16777216 STRam hatari
        !            98:   321536 CyclePalettes hatari
        !            99:   262144 mem_banks hatari
        !           100:   262144 cpufunctbl hatari
        !           101:   131072 pInterceptWriteTable hatari
        !           102:   131072 pInterceptReadTable hatari
        !           103:    69632 InternalDTAs hatari
        !           104:    65536 EnvelopeShapeValues hatari
        !           105:    53588 DialogParams hatari
        !           106:    53588 ConfigureParams hatari
        !           107:    19976 FrameBuffers hatari
        !           108:    16384 ST2RGB hatari

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