Consider the following four processes with arrival times (in milliseconds) and their length of CPU bursts (in milliseconds) as shown below :
These processes are run on a single processor using preemptive Shortest Remaining Time First scheduling algorithm. If the average waiting time of the processes is 1 millisecond, then the value of Z is _____.
Your input ____
2
GATE CSE 2019
Numerical
+1
-0
Consider three concurrent processes P1, P2 and P3 as shown below, which access a shared variable D that has been initialized to 100.
The processes are executed on a uniprocessor system running a time-shared operating system. If the minimum and maximum possible values of D after the three processes have completed execution are X and Y respectively, then the value of Y–X is _________.
Your input ____
3
GATE CSE 2019
MCQ (Single Correct Answer)
+2
-0.67
Consider the following snapshot of a system running $n$ concurrent processes. Process $i$ is holding $X_i$ instances of a resource $\mathrm{R}, 1 \leq i \leq n$. Assume that all instances of R are currently in use. Further, for all $i$, process $i$ can place a request for at most $Y_i$ additional instances of R while holding the $X_i$ instances it already has. Of the $n$ processes, there are exactly two processes $p$ and $q$ such that $Y_p=Y_q=0$. Which one of the following conditions guarantees that no other process apart from $p$ and $q$ can complete execution?
A
$X_p + X_q < \min \{Y_k \mid 1 \leq k \leq n, k \neq p, k \neq q\}$
B
$X_p + X_q < \max \{Y_k \mid 1 \leq k \leq n, k \neq p, k \neq q\}$
C
$\min (X_p, X_q) \geq \min \{Y_k \mid 1 \leq k \leq n, k \neq p, k \neq q\}$
D
$\min (X_p, X_q) = \max \{Y_k \mid 1 \leq k \leq n, k \neq p, k \neq q\}$
4
GATE CSE 2019
Numerical
+2
-0
The index node (inode) of a Unix-like file system has 12 direct, one single-indirect and one double-indirect pointers. The disk block size is 4 kB , and the disk block address is 32 -bits long. The maximum possible file size is (rounded off to 1 decimal place) ___________ GB.
