[openwrt/openwrt] image: let mksquashfs4 use all processors

[LEDE Commits]

aparcar pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/df2ae8826ced4f374bcb693b44d8a113ad150d70

commit df2ae8826ced4f374bcb693b44d8a113ad150d70
Author: Stijn Tintel <stijn at linux-ipv6.be>
AuthorDate: Sat Feb 19 17:54:22 2022 +0200

    image: let mksquashfs4 use all processors
    
    Drop the -processors argument from the mksquashfs4 call, so it will use
    all available processors. This dramatically reduces the time to create
    squashfs filesystems.
    
    The times below are observed when building an image for my main router,
    the WatchGuard Firebox M300 (qoriq target):
    
    Before:
    real    4m45,973s
    
    After:
    real    0m23,497s
    
    With this commit `mksquashfs` may use more cores than defined via `-j`.
    This is the same behaviour as for archive creation of ImageBuilder, SDK
    or toolchain. There is no trivial way to limit `mksquashfs` CPU core
    usage to the amount of "free" make jobs since two running `mksquashfs`
    instances would each run with the total allowed number (-j) of threads.
    
    Signed-off-by: Stijn Tintel <stijn at linux-ipv6.be>
    [extended reasoning in commit message]
    Signed-off-by: Paul Spooren <mail at aparcar.org>
---
 include/image.mk | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/image.mk b/include/image.mk
index e5b52d0e97..35a5e291c6 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -230,8 +230,7 @@ $(eval $(foreach S,$(NAND_BLOCKSIZE),$(call Image/mkfs/jffs2-nand/template,$(S))
 define Image/mkfs/squashfs-common
 	$(STAGING_DIR_HOST)/bin/mksquashfs4 $(call mkfs_target_dir,$(1)) $@ \
 		-nopad -noappend -root-owned \
-		-comp $(SQUASHFSCOMP) $(SQUASHFSOPT) \
-		-processors 1
+		-comp $(SQUASHFSCOMP) $(SQUASHFSOPT)
 endef
 
 ifeq ($(CONFIG_TARGET_ROOTFS_SECURITY_LABELS),y)