default or selected kernelversion does not have config value CONFIG_NET_SCH_DSMARK.
Result is shown for kernelversion 6.7.6

Differentiated Services marker (DSMARK)

modulename: sch_dsmark.ko

configname: CONFIG_NET_SCH_DSMARK

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>QoS and/or fair queueing
└─>Differentiated Services marker (DSMARK)
In linux kernel since version 2.6.12  
Say Y if you want to schedule packets according to the
Differentiated Services architecture proposed in RFC 2475.
Technical information on this method, with pointers to associated
RFCs, is available at <http://www.gta.ufrj.br/diffserv/>.

To compile this code as a module, choose M here: the
module will be called sch_dsmark.

source code: