ClamAV/clamsap allocates 1GB of anon memory segment for each SAP worker process

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Environment

SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server for SAP Applications 12

Situation

The system is facing high memory usage as clamAV/clamsap allocates 1GB of anonymous memory segment for each SAP worker process, which can lead to an Out Of Memory situation.

The "pmap -XX" output shows 1GB of anonymous segments for each dw.sap task mapped at 0x7f6d91e83000:

23733:   dw.sapRDX_D00 pf=/usr/sap/RDX/SYS/profile/RDX_D00_sapnode1
         Address Perm   Offset Device     Inode     Size Private_Dirty Referenced Anonymous   
    56406d94a000 r-xp 00000000  fe:01 134310103    67820             0      29024         0   
    564077378000 rw-p 00000000  00:00         0     6076          1316       1304      1372   
    564077967000 rw-p 00000000  00:00         0    17672         13700      13700     13700   
    7f6d91e83000 rw-p 00000000  00:00         0  1057904       1032992    1032992   1032992 

 32145:   dw.sapRDX_D00 pf=/usr/sap/RDX/SYS/profile/RDX_D00_sapnode1
         Address Perm   Offset Device     Inode     Size  Private_Dirty Referenced Anonymous
    56406d94a000 r-xp 00000000  fe:01 134310103    67820              0      40412         0
    564071d84000 r--p 0423a000  fe:01 134310103     1604              0        520       524
    564077967000 rw-p 00000000  00:00         0    32784          25272      25272     25272
    7f6d91e43000 rw-p 00000000  00:00         0      132            132        132       132
    7f6d91e83000 rw-p 00000000  00:00         0  1057904        1018240    1018240   1018240
...

Resolution

This issue is fixed by using the multithreaded version of libclamsap library, libclamdsap.so instead of libclamsap.so, as "Adapter Path".
This is documented here:
https://documentation.suse.com/sles-sap/15-SP4/single-html/SLES-SAP-guide/#sec-clamsap-library

Status

Reported to Engineering

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