Shared Memory error

[Larrhy-Martin]

Hello,

I urgently need your help to solve this : running on an HP-UX server 11.11 a process that loads from a database Xref files to the shared memory, I have the following error : Illegal Shared Memory Size -2140822496.
From the log of the process, I notice that the files loading stops at a file that might be above 2Gb.
What can be the reason of this ? The shared memory can not contain a file bigger than 2Gb ? Is there any tunable kernel parameter related to this ? My RAM is 16Gb and below, my Kernel params.

root@rating2:/root#kmtune
Parameter Current Dyn Planned Module Version
===============================================================================
NSTRBLKSCHED - - 2
NSTREVENT 50 - 50
NSTRPUSH 16 - 16
NSTRSCHED 0 - 0
STRCTLSZ 1024 - 1024
STRMSGSZ 65535 - 65535
acctresume 4 - 4
acctsuspend 2 - 2
aio_listio_max 256 - 256
aio_max_ops 2048 - 2048
aio_physmem_pct 10 - 10
aio_prio_delta_max 20 - 20
allocate_fs_swapmap 0 - 0
alwaysdump 1 - 1
bcvmap_size_factor 2 - 2
bootspinlocks - - 256
bufcache_hash_locks 128 - 128
bufpages 0 - (NBUF*2)
chanq_hash_locks 256 - 256
core_addshmem_read 0 Y 0
core_addshmem_write 0 Y 0
create_fastlinks 0 - 0
dbc_max_pct 5 - 5
dbc_min_pct 2 - 2
default_disk_ir 0 - 0
desfree - - 0
disksort_seconds 0 - 0
dmp_max_msecs 10000 - 10000
dmp_pathsw_bshift 10 - 10
dmp_rootdev_is_vol 0 - 0
dmp_swapdev_is_vol 0 - 0
dnlc_hash_locks 512 - 512
dontdump 0 - 0
dskless_node - - 0
dst 1 - 1
effective_maxpid - - ((NPROC<=30000)?30000:(NPROC*5/4))
eisa_io_estimate - - 0x300
enable_idds 0 - 0
eqmemsize 15 - 15
executable_stack 1 - 1
fcp_large_config 0 - 0
file_pad - - 10
fs_async 0 - 0
ftable_hash_locks 64 - 64
hdlpreg_hash_locks 128 - 128
hfs_max_ra_blocks 20 - 20
hfs_max_revra_blocks 8 - 8
hfs_ra_per_disk 256 - 256
hfs_revra_per_disk 64 - 64
hp_hfs_mtra_enabled 1 - 1
hpux_aes_override - - 0
initmodmax 50 - 50
io_ports_hash_locks 64 - 64
iomemsize - - 40000
ksi_alloc_max 81920 - (NPROC*8)
ksi_send_max 32 - 32
lotsfree - - 0
max_async_ports 50 - 50
max_fcp_reqs 512 - 512
max_mem_window 0 - 0
max_thread_proc 2048 - 2048
maxdsiz 3221225472 - 3221225472
maxdsiz_64bit 274877906944 - 274877906944
maxfiles 2048 - 2048
maxfiles_lim 2048 Y 2048
maxqueuetime - - 0
maxssiz 134217728 - 134217728
maxssiz_64bit 1073741824 - 1073741824
maxswapchunks 16384 - 16384
maxtsiz 0x3ff00000 Y 0X3FF00000
maxtsiz_64bit 0xffff0000 Y 0XFFFF0000
maxuprc 9216 Y ((NPROC*9)/10)
maxusers 1024 - 1024
maxvgs 80 - 80
mesg 1 - 1
minfree - - 0
modstrmax 500 - 500
msgmap 10242 - (2+MSGTQL)
msgmax 32768 Y 32768
msgmnb 65536 Y 65536
msgmni 10240 - (NPROC)
msgseg 32767 - 32767
msgssz 128 - 128
msgtql 10240 - (NPROC)
nbuf 0 - 0
ncallout 17952 - (16+NKTHREAD)
ncdnode 150 - 150
nclist 16484 - (100+16*MAXUSERS)
ncsize 96064 - (NINODE+VX_NCSIZE)+(8*DNLC_HASH_LOCKS)
ndilbuffers 30 - 30
netisr_priority - - -1
netmemmax - - 0
nfile 155648 - (15*NPROC+2048)
nflocks 10240 - (NPROC)
nhtbl_scale 0 - 0
ninode 83968 - (8*NPROC+2048)
nkthread 17936 - (((NPROC*7)/4)+16)
nni - - 2
no_lvm_disks 0 - 0
nproc 10240 - (2048+8*MAXUSERS)
npty 200 - 200
nstrpty 200 - 200
nstrtel 60 - 60
nswapdev 10 - 10
nswapfs 10 - 10
nsysmap 20480 - ((NPROC)>800?2*(NPROC):800)
nsysmap64 20480 - ((NPROC)>800?2*(NPROC):800)
o_sync_is_o_dsync 0 - 0
page_text_to_local - - 0
pfdat_hash_locks 128 - 128
public_shlibs 1 - 1
region_hash_locks 128 - 128
remote_nfs_swap 0 - 0
rtsched_numpri 32 - 32
scroll_lines 100 - 100
scsi_max_qdepth 8 Y 8
scsi_maxphys 1048576 - 1048576
select_enh 0 Y 0
sema 1 - 1
semaem 16384 - 16384
semmap 10242 - (SEMMNI+2)
semmni 10240 - (NPROC)
semmns 20480 - (SEMMNI*2)
semmnu 10236 - (NPROC-4)
semmsl 2048 Y 2048
semume 512 - 512
semvmx 32767 - 32767
sendfile_max 0 - 0
shmem 1 - 1
shmmax 0x3ffe00000 Y 0X3FFE00000
shmmni 1024 - 1024
shmseg 768 Y 768
st_ats_enabled 0 - 0
st_fail_overruns 0 - 0
st_large_recs 0 - 0
st_san_safe 0 - 0
streampipes 0 - 0
swapmem_on 1 - 1
swchunk 2560 - 2560
sysv_hash_locks 128 - 128
tcphashsz 0 - 0
timeslice 10 - (100/10)
timezone 420 - 420
unlockable_mem 0 - 0
vas_hash_locks 128 - 128
vnode_cd_hash_locks 128 - 128
vnode_hash_locks 128 - 128
vol_checkpt_default 10240 - 10240
vol_dcm_replay_size 262144 - (256*1024)
vol_default_iodelay 50 - 50
vol_fmr_logsz 4 - 4
vol_max_bchain 32 - 32
vol_max_nconfigs 20 - 20
vol_max_nlogs 20 - 20
vol_max_nmpool_sz 4194304 - (4*1024*1024)
vol_max_prm_dgs 1024 - 1024
vol_max_rdback_sz 4194304 - (4*1024*1024)
vol_max_vol 8388608 - (8*1024*1024)
vol_maxio 256 - 256
vol_maxioctl 32768 - 32768
vol_maxkiocount 2048 - 2048
vol_maxparallelio 256 - 256
vol_maxspecialio 256 - 256
vol_maxstablebufsize 256 - 256
vol_min_lowmem_sz 524288 - (512*1024)
vol_mvr_maxround 256 - 256
vol_nm_hb_timeout 10 - (10)
vol_subdisk_num 4096 - 4096
vol_vvr_transport 1 - (1)
vol_vvr_use_nat 0 - (0)
volcvm_cluster_size 16 - 16
volcvm_smartsync 1 - 1
voldrl_max_drtregs 2048 - 2048
voldrl_min_regionsz 512 - 512
voliomem_chunk_size 65536 - (64*1024)
voliomem_maxpool_sz 4194304 - (4*1024*1024)
voliot_errbuf_dflt 16384 - 16384
voliot_iobuf_default 8192 - 8192
voliot_iobuf_limit 131072 - 131072
voliot_iobuf_max 65536 - 65536
voliot_max_open 32 - 32
volraid_rsrtransmax 1 - 1
vps_ceiling 64 - 64
vps_chatr_ceiling 1048576 - 1048576
vps_pagesize 4 - 4
vx_fancyra_enable 0 - 0
vx_maxlink 32767 - 32767
vx_ncsize 8000 - 8000
vx_ninode 0 - 0
vxfs_max_ra_kbytes 1024 - 1024
vxfs_ra_per_disk 1024 - 1024
vxtask_max_monitors 32 - 32
x25_setup_pvc_timer - - 0


Thanks to all !

[Dennis Handly]

>a process that loads from a database Xref files to the shared memory, I have the following error: Illegal Shared Memory Size -2140822496.

This application is broken. It should not be treating shmmax as a signed int, it should be unsigned in or unsigned long long.

(gdb) p /x -2140822496 -> 0x8065a420
(gdb) p (unsigned int)-2140822496 -> 2154144800
(Unfortunately I can't see how that number comes from your shmmax 0x3ffe00000?

>Is there any tunable kernel parameter related to this?

You might have to reduce shmmax if you can't get your application fixed.

>The shared memory can not contain a file bigger than 2Gb?

Note a 32 bit application can't really get a segment above 1 Gb.

[Steven E. Protter]

Shalom,

set shmmax as big as you can, up to 16 GB and that should resolve the problem.

Some of the parameters on this system appear to be default.

SEP