Start an SSH daemon in debug mode:

/usr/sbin/sshd -d -p 2222

Connect with client in verbose mode:

ssh -vv -p 2222 ServerIP

If fcntl is used to aquire locks on files without utilization of the range/region parameters, file locks are aquired without an offset, which has the side-effect of the lock entry being inserted at the beginning of the kernel's lock table.

Interestingly, if an application relies on intensive utilization of such file locking, the overhead of unconditional traversal of the potentially over-sized set of lock entries crowded into the front of the lock table can be quite impactful.

In one particular application, file locks acquired via fcntl was used for IPC-oriented synchronization in addition to actual concurrent file access, which introduced the overhead from kernel lock table front-loading to the application's multi-threaded processing concurrency - and the problem was also aggrevated by the addition IPC-oriented lock volume, as well.

One mitigation technique would be to utilize the region/range parameters for fcntl, locking a region at an arbitrarily-high position, which has the side-effect of the lock entry being located away from the front of the lock table.

This sample .kshrc file is typically paired with a .profile containing simply:

export ENV=${HOME}/.kshrc

# A .twmrc file personalized by rk4n3
UsePPosition on
RandomPlacement
NoGrabServer
OpaqueMove
RestartPreviousState
DecorateTransients
#ClientBorderWidth
#NoDefaults

TitleFont			"-*-fixed-medium-r-*-*-12-*-*-*-*-*-*-*"
ResizeFont			"-*-fixed-medium-r-*-*-12-*-*-*-*-*-*-*"
MenuFont				"-*-fixed-medium-r-*-*-12-*-*-*-*-*-*-*"
IconFont				"-*-fixed-medium-r-*-*-12-*-*-*-*-*-*-*"
IconManagerFont		"-*-fixed-medium-r-*-*-12-*-*-*-*-*-*-*"

Color {
   DefaultBackground     "rgb:0/0/0"
   DefaultForeground     "rgb:F/F/F"
   BorderColor           "rgb:C/C/4"
   TitleBackground       "rgb:3/3/3"
   TitleForeground       "rgb:C/A/0"
   MenuBackground        "rgb:2/2/2"
   MenuForeground        "rgb:C/A/0"
   MenuBorderColor       "rgb:F/F/0"
   MenuTitleBackground   "rgb:4/4/4"
   MenuTitleForeground   "rgb:F/F/0"
   IconBackground        "rgb:4/4/4"
   IconForeground        "rgb:C/A/0"
   IconBorderColor       "rgb:4/4/4"
   IconManagerBackground "rgb:4/4/4"
   IconManagerForeground "rgb:C/C/4"
}

NoTitle { "stalonetray" }

# Define some useful functions for motion-based actions.
MoveDelta 3
Function "move-or-lower" { f.move f.deltastop f.lower }
Function "move-or-raise" { f.move f.deltastop f.raise }
Function "move-or-iconify" { f.move f.deltastop f.iconify }

# Set some useful bindings.  Sort of uwm-ish, sort of simple-button-ish
#LeftTitleButton ":iconify" = f.iconify
#RightTitleButton ":resize" = f.resize

Button1 =   : root        : f.menu "MainMenu"

Button1 = m : window|icon : f.function "move-or-lower"
Button2 = m : window|icon : f.iconify
Button3 = m : window|icon : f.function "move-or-raise"

Button1 =   : title       : f.function "move-or-raise"
Button2 =   : title       : f.raiselower
Button3 =   : title       : f.menu "simplewinops"

Button1 =   : icon        : f.function "move-or-iconify"
Button2 =   : icon        : f.iconify

Button1 =   : iconmgr     : f.iconify
Button2 =   : iconmgr     : f.iconify

#
# And a menus with the usual things
#
menu "winops" {
"Iconify"				f.iconify
"Resize"					f.resize
"Move"					f.move
"Raise"					f.raise
"Lower"					f.lower
"-------------"		f.nop
"Focus"					f.focus
"Unfocus"				f.unfocus
"Show Iconmgr"			f.showiconmgr
"Hide Iconmgr"			f.hideiconmgr
"-------------"		f.nop
"Kill"					f.destroy
"Delete"					f.delete
"Lower"					f.lower
}

menu "simplewinops" {
"Lower"					f.lower
"Close"					f.delete
"Kill"					f.destroy
}

menu "tools" {
"Edit .twmrc"			f.exec "exec gvim ~/.twmrc &"
"Restart TWM"			f.restart
"-------------"		f.nop
"Window..."				f.menu "winops"
"============="		f.nop
"Exit TWM"				f.quit
}

menu "MainMenu" {
"rk4n3@darkstar"		f.title
"Terminal"				f.exec "exec terminator &"
"File Manager"			f.exec "exec xfe &"
"-------------"		f.nop
"Tools"					f.menu "tools"
"Close window..."		f.delete
"-------------"		f.nop
"Geeqie"					f.exec "exec geeqie &"
"Open Office"			f.exec "exec soffice &"
"Firefox"				f.exec "firefox &"
}