According to the Linux kernel documentation, "SwapCached" tracks "memory
that once was swapped out, is swapped back in but still also is
in the swapfile (if memory is needed it doesn't need to be swapped out
AGAIN because it is already in the swapfile. This saves I/O)."
It is only used on Linux to optimize memory handling in case the command
changes to a smaller-or-equal string.
This "optimization" however causes more code bloat and maintenance cost
on string handling issues than it gains.
There is a possible path - albeit theoretical really - through
the btime initialization code in Linux ProcessList_new(), when
String_startsWith() is always false, which can result in btime
not being initialized.
This commit refactors the code to remove that possibility.
Small cleanups - add error handling, remove a local static
variable and refactor LinuxProcess_adjustTime (also rename
it, as its in LinuxProcessList.c not LinuxProcess.c) - and
while there, move the related 'btime' global variable into
LinuxProcessList.c so it can be made static.
Resolves https://github.com/htop-dev/htop/issues/384
By storing the per-process m_resident and m_virt values in the form
htop wants to display them in (KB, not pages), we no longer need to
have definitions of pageSize and pageSizeKB in the common CRT code.
These variables were never really CRT (i.e. display) related in the
first place. It turns out the darwin platform code doesn't need to
use these at all (the process values are extracted from the kernel
in bytes not pages) and the other platforms can each use their own
local pagesize variables, in more appropriate locations.
Some platforms were actually already doing this, so this change is
removing duplication of logic and variables there.
linux/LinuxProcessList.c:1403:63: runtime error: division by zero
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior linux/LinuxProcessList.c:1403:63 in
The global ProcessList structure contains a couple of unused
fields. 'sharedMem' has never been used by any Meter, since
its not been anything other than zero in Linux /proc/meminfo
for many, many years. The freeMem field is only used in the
usedMem calculation, so it can reside on the stack like some
other memory variables used within-calculations-only and not
exposed to the user via a Meter.
taskstats is only checked on runtime if the column RCHAR, WCHAR, SYSCR,
SYSCW, RBYTES, WBYTES, CNCLWB, IO_READ_RATE, IO_WRITE_RATE or IO_RATE is
selected.
taskstats is currently enabled by default.
Drop the taskstats configuration switch, to reduce the maintenance cost.
cgroup is only checked on runtime if the column CGROUP is selected.
cgroup is currently disabled by default, but most distributions do
enable it.
Drop the cgroup configuration switch, to reduce the maintenance cost.
Christian Göttsche