Tuning memory layout

Hello everyone!

I got my DSP application work but I stumble upon unexpected low performance. I suspect my memory layout is far from optimal. Now it looks like this

MEMORY
{
    DSPL2ROM     o = 0x00700000  l = 0x00100000     /* 1MB L2 Internal ROM */                
    DSPL2RAM     o = 0x00800000  l = 0x00040000     /* 256kB L2 Internal RAM */              
    DSPL1PRAM    o = 0x00E00000  l = 0x00008000     /* 32kB L1 Internal Program RAM */        
    DSPL1DRAM    o = 0x00F00000  l = 0x00008000     /* 32kB L1 Internal Data RAM */           
    SHDSPL2ROM   o = 0x11700000  l = 0x00100000     /* 1MB L2 Shared Internal ROM */         
    SHDSPL2RAM   o = 0x11800000  l = 0x00040000     /* 256kB L2 Shared Internal RAM */       
    SHDSPL1PRAM  o = 0x11E00000  l = 0x00008000     /* 32kB L1 Shared Internal Program RAM */
    SHDSPL1DRAM  o = 0x11F00000  l = 0x00008000     /* 32kB L1 Shared Internal Data RAM */    
    SHRAM        o = 0x80000000  l = 0x00020000     /* 128kB Shared RAM */                   
    EMIFBSDRAM   o = 0xC0000000  l = 0x10000000     /* 256MB SDRAM Data */                   
}                                                                       

SECTIONS
{
    .text          >  DSPL2RAM
    .stack         >  DSPL2RAM
    .bss           >  DSPL2RAM
    .cio           >  EMIFBSDRAM
    .const         >  EMIFBSDRAM
    .data          >  EMIFBSDRAM
    .switch        >  EMIFBSDRAM
    .sysmem        >  EMIFBSDRAM
    .far           >  SHDSPL2RAM
    .args          >  SHRAM
    .ppinfo        >  SHRAM
    .ppdata        >  SHRAM
  
    /* COFF sections */
    .pinit         >  EMIFBSDRAM
    .cinit         >  EMIFBSDRAM
  
    /* EABI sections */
    .binit         >  SHRAM
    .init_array    >  SHRAM
    .neardata      >  SHRAM
    .fardata       >  SHRAM
    .rodata        >  SHRAM
    .c6xabi.exidx  >  SHRAM
    .c6xabi.extab  >  SHRAM

    .cio		>		SHRAM				/* C I/O Buffer						*/
	.vecs		>		SHRAM				/* Interrupt Vectors				*/
}

To be honest I don't even know what a half of sections is for (.ppinfo, .args, .switch and so on).
Would it be better to place code and data on different memory devices (SHRAM vs DSPL2RAM)?
Speaking generally I have a lot of questions. Are there any manuals about tuning memory layout? Which document I should read first?

Thanks.