why does malloc not give memory that is available?

[marcmerlin]

Code: Select all

printf("Heap/32-bit Memory Available: %6d bytes total, %6d bytes largest free block\n", heap_caps_get_free_size(0), heap_caps_get_largest_free_block(0));
uint32_t mallocsize = m_absMWidth * m_absBWidth * m_absMHeight * m_absBHeight * sizeof(CRGB);
p_LED = (struct CRGB *) malloc(mallocsize);
if (! p_LED) { Serial.print("Malloc LEDMatrix Failed. Bytes requested: "); Serial.println(mallocsize);}

returns

Code: Select all

Heap/32-bit Memory Available: 136444 bytes total,  82808 bytes largest free block
Malloc LEDMatrix Failed. Bytes requested: 49152

I'm confused, why?

[chegewara]

[marcmerlin]

Turns out I had to print 8bit memory, I forgot about that.
Heap/32-bit Memory Available: 139756 bytes total, 82808 bytes largest free block
8-bit/DMA Memory Available : 56804 bytes total, 43520 bytes largest free block
Malloc LEDMatrix Failed. Bytes requested: 49152

So, this explains that. Sad that ESP32 memory is hard to deal with/fragmented. I have 140KB free, but most of that memory is 32bit only, so I can't use it for a regular malloc.