malloc() in libc.obj gets at least 4k every time #205

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rgimad · 2025-04-10T12:53:10+02:00

rgimad commented

2025-04-10 12:53:10 +02:00

malloc() in libc.obj gets at least 4k every time, because it is just a wrapper of sysfn 68.12 (

		programs/develop/ktcc/trunk/libc.obj/source/stdlib/malloc.c
		Line 6 in fcb9f49785
	
				    return _ksys_alloc(size);

) that allocates at least 4k page even if you need i.e 20 bytes.

TODO: write a normal allocator (e.g. dlmalloc, etc.) in malloc() that will request new pages only when neccessary

malloc() in libc.obj gets at least 4k every time, because it is just a wrapper of sysfn 68.12 (https://git.kolibrios.org/KolibriOS/kolibrios/src/commit/fcb9f49785bf55de1616350d942edca9f2a33034/programs/develop/ktcc/trunk/libc.obj/source/stdlib/malloc.c#L6) that allocates at least 4k page even if you need i.e 20 bytes. TODO: write a normal allocator (e.g. dlmalloc, etc.) in malloc() that will request new pages only when neccessary

rgimad added the

labels 2025-04-10 12:53:10 +02:00

Leency commented

2025-04-10 12:58:35 +02:00

TODO: write a normal allocator for malloc that will request new pages only when neccessary

Previous devepers told that heap alloc must not be requested for a small portions, such feature has to be done at app level.

> TODO: write a normal allocator for malloc that will request new pages only when neccessary Previous devepers told that heap alloc must not be requested for a small portions, such feature has to be done at app level.

rgimad commented

2025-04-10 13:03:17 +02:00

Previous devepers told that heap alloc must not be requested for a small portions, such feature has to be done at app level.

I say the same thing, sysfn is okay, malloc in library is not okay

> Previous devepers told that heap alloc must not be requested for a small portions, such feature has to be done at app level. I say the same thing, sysfn is okay, malloc in library is not okay

👍 1

dunkaist commented

2025-04-10 14:23:42 +02:00

Do you plan to implement something like this? https://git.kolibrios.org/KolibriOS/kolibrios/src/branch/main/programs/system/os/malloc.inc