[FS#120] opkg fails with Out of memory on a device with 32 MB of RAM

[LEDE Bugs]

The following task has a new comment added:

FS#120 - opkg fails with Out of memory on a device with 32 MB of RAM
User who did this - Alberto Bursi (bobafetthotmail1)

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Still fails when it really shouldn't. it seems wget fails to download a 4kib package while I have 8 MiB of free RAM + 12 MiB of caches.

root at lede:/# opkg install luci-app-minidlna
Installing luci-app-minidlna (git-16.365.41161-ca79611-1) to root...
Downloading http://downloads.lede-project.org/snapshots/packages/mips_24kc/luci/luci-app-minidlna_git-16.365.41161-ca79611-1_all.ipk.
Collected errors:
 * xsystem: wget: vfork: Out of memory.
 * opkg_download: Failed to download http://downloads.lede-project.org/snapshots/packages/mips_24kc/luci/luci-app-minidlna_git-16.365.41161-ca79611-1_all.ipk, wget returned -1.
 * opkg_install_pkg: Failed to download luci-app-minidlna. Perhaps you need to run 'opkg update'?
 * opkg_install_cmd: Cannot install package luci-app-minidlna.

root at lede:/# free
             total       used       free     shared    buffers     cached
Mem:         27940      19156       8784        560       1044       3704
-/+ buffers/cache:      14408      13532
Swap:            0          0          0

root at lede:/# cat /proc/meminfo
MemTotal:          27940 kB
MemFree:            7996 kB
MemAvailable:      10660 kB
Buffers:            1120 kB
Cached:             3716 kB
SwapCached:            0 kB
Active:             3840 kB
Inactive:           2172 kB
Active(anon):       1704 kB
Inactive(anon):       32 kB
Active(file):       2136 kB
Inactive(file):     2140 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:          1184 kB
Mapped:             1644 kB
Shmem:               560 kB
Slab:               7068 kB
SReclaimable:       1892 kB
SUnreclaim:         5176 kB
KernelStack:         328 kB
PageTables:          216 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:       13968 kB
Committed_AS:       4312 kB
VmallocTotal:    1048372 kB
VmallocUsed:           0 kB
VmallocChunk:          0 kB
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=120#comment1127