1G HugeTLB Page

[syamalasaripall]

Hi,

I am trying to change HugeTLB size from 256Mb to 1G.

I observe 1G page getting allocated in kernel.

[ 0.479637] HugeTLB registered 1 GB page size, pre-allocated 1 pages
[ 0.485914] HugeTLB registered 1 MB page size, pre-allocated 0 pages
[ 0.492253] HugeTLB registered 4 MB page size, pre-allocated 0 pages
[ 0.498595] HugeTLB registered 16 MB page size, pre-allocated 0 pages
[ 0.505028] HugeTLB registered 64 MB page size, pre-allocated 0 pages
[ 0.511453] HugeTLB registered 256 MB page size, pre-allocated 0 pages

/proc/sys/kernel/shmmax is also updated to 1G
Loading DSP image also fine. But any shmmat from app to allocated segment fails 

===B4860QDS DSP boot Application (3.0.0) ===
SYSTEM MAP
DSP PrivArea: Addr=c0000000 Size=3ff00000
Shared CtrlArea: Addr=fff00000 Size=100000
DSP Core0 M2: Addr=0 Size=0
DSP Core1 M2: Addr=0 Size=0
DSP M3: Addr=c40000000 Size=8000
PA CCSRBAR: Addr =ffe000000 Size=1000000
DSP CCSRBAR: Addr =ffe000000 Size=1000000
PA Shared Area: Addr=80000000 Size=3f000000
DSP Shared Area: Addr=bf000000 Size=1000000
Loading Dsp image /usr/bin/L1_cu_combined.bin

.........
sleep 1, waiting for hw sem
sleep 1, waiting for hw sem
HS_MPR[1]=0xfe
HS_MPR[1]=0x0

== DSP Booted up ==

[root@0005B932EFD4 /]# ipcs -m

------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000002 0 root 600 1073741824 0

[root@0005B932EFD4 /]# cat /proc/meminfo | grep Huge
HugePages_Total: 1
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 1048576 kB

[root@0005B932EFD4 /]#

But from App, shmat fails for same shmid/key

dsplog -c showlog -n gstLOGDebugNC
SYSTEM MAP
DSP PrivArea: Addr=c0000000 Size=3ff00000
Shared CtrlArea: Addr=fff00000 Size=100000
DSP Core0 M2: Addr=0 Size=0
DSP Core1 M2: Addr=0 Size=0
DSP M3: Addr=c40000000 Size=8000
PA CCSRBAR: Addr =ffe000000 Size=1000000
DSP CCSRBAR: Addr =ffe000000 Size=1000000
shmat: Cannot allocate memory
Shared memory attach failure: Cannot allocate memory
Segmentation fault (core dumped)

Same works for 256Mb, but only fails for 1G. So, is there any constraint or config for 1G HugeTLB.

[yipingwang]

Hello Syamala Saripalli,

Increase huge page size, just set uboot env hugepagesz=1024m
To use 1GB on PA side: Modify this in libdspboot.c,
(shared_area).pa_ipc_shared.phys_addr = (unsigned long)pa_p;

(shared_area).pa_ipc_shared.size = MB_256 - (*het_sys_map).dsp_shared_size;
(shared_area).dsp_ipc_shared.phys_addr= (unsigned long)pa_p + MB_256 - (*het_sys_map).dsp_shared_size;

And this in /fsl_shm/lib/lg_shm.c
shmid = shmget(LG_SHM_KEY, HUGE_PAGE_256M,SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W);
if (shmid<0) {
perror("shmget");
close(fd);

return NULL;
}

memset(&shm, 0, sizeof(shm_seg_t));
shm.vaddr = (__u32)shmat(shmid, 0, 0);

if (shm.vaddr == -1) {
perror("Shared memory attach failure");
shmctl(shmid, IPC_RMID, NULL);

close(fd);
return NULL;}
shm.size = HUGE_PAGE_256M - (dsp_shared_size + IPC_METADATA_AREA_SZ);

ret = ioctl(fd, IOCTL_FSL_SHM_INIT,&shm);
if (ret == -1)

You can see the total size of pa_shared+ dsp_shared = bootm_size, you can set dsp_shared_size by passing it to hetmgr.k

Have a great day,
TIC

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