problem with power supply

hi guys, my project is almost complete,but there is problem with powering it through a single power supply. my project is gsm enabled switch. the components are:- arduino nano, gsm 900a module, led, and a servo motor( arduino is powering the gsm900a module and the led, the servo is powered by separate power suplly. if i power arduino and servo with separate 5v power adapter, the project is working, but when i power both arduino and servo with single 5v power adapter then the arduino restarts. so can someone help me out with this so that i can power both arduino and servo with a single power supply.

No experience with the GSM or servo, but I found peak currents of 1.8Amp for the GSM module, and a stall current of 1.5Amp for the servo. The supply should be able to deliver that current.

Powering with separate supplies is good - sharing power between motors (like a servo) and digital logic (like Arduino/GSM shield) is poor practice.

so what will be the best way of sharing the power supply, so that i have only one power cord going into the ac main(like a mobile power adapter) to power my project??

connect both the supplies to an IEC socket in the case of your project so a kettle-lead can be used to the wall? You can add a fuse/switch as well if it makes sense.