Quantcast
Channel: Make -j (multiple jobs) with number specified doesn't work in QNX - Stack Overflow
Viewing all articles
Browse latest Browse all 2

Make -j (multiple jobs) with number specified doesn't work in QNX

0
0

From various sources (like this) state that you can parallelise your build jobs with:

make -j n

where n is the number of jobs. In QNX 6.5.0 with GNU Make 3.81 I noticed that the number doesnt seem to work. If i call make -j (no number) a huge number of compilers will be started and the processors will be used fully:

CPU states: 80.5% user, 5.0% kernel
CPU  0 Idle: 15.2%
CPU  1 Idle: 13.2%
CPU  2 Idle: 14.7%
Memory: 0 total, 281M avail, page size 4K

      PID   TID PRI STATE    HH:MM:SS    CPU  COMMAND
     8200     2  21 Rcv       0:00:17  12.02% devb-eide
 43565087     1  10 Rdy       0:00:00  11.38% make
 43819103     1  10 Rply      0:00:00   3.01% cmake
 43716678     1  10 Rply      0:00:00   2.80% cmake
 43671611     1  10 Rply      0:00:00   1.87% make
 43589671     1  10 Rply      0:00:00   1.73% make
 43569184     1  10 Rply      0:00:00   1.73% make
 43573283     1  10 Rply      0:00:00   1.46% make
 43667514     1  10 Rply      0:00:00   1.28% make
 43839590     1  10 Send      0:00:00   1.10% cmake

Unfortunately when i use make -j having the huge number of concurrent builds means that my limited VM quickly runs out of memory.

But if I add a number (eg. make -j 4, which corresponds to the number of cores in my VM) then it will only ever start 1 process. This also occurs with the following variants:

make -j4
make -j 4
make --jobs=4
make --jobs 4

As well as with some other processor numbers (2, 3, 4, 5, 6, 7, 8).

Why doesnt make -j with a specified number work in QNX?


Viewing all articles
Browse latest Browse all 2

Latest Images

Trending Articles





Latest Images