On 07/12/2018 07:33 PM, Eric W. Biederman wrote: > > Adrian Reber <adr...@lisas.de> writes: > >> The CHECKPOINT_RESTORE configuration option was introduced in 2012 and >> combined with EXPERT. CHECKPOINT_RESTORE is already enabled in many >> distribution kernels and also part of the defconfigs of various >> architectures. >> >> To make it easier for distributions to enable CHECKPOINT_RESTORE this >> removes EXPERT and moves the configuration option out of the EXPERT >> block. > > I think we should change the help text at the same time, to match > our improve understanding of the situation. > > Does anyone remember why this option was added at all?
Sure! Quoting Andrew's ~7 years ago akpm branch merge e-mail: However I'm less confident than the developers that it will all eventually work! So what I'm asking them to do is to wrap each piece of new code inside CONFIG_CHECKPOINT_RESTORE. So if it all eventually comes to tears and the project as a whole fails, it should be a simple matter to go through and delete all trace of it. the best link with full e-mail I googled for is https://gitlab.imag.fr/kaunetem/linux-kaunetem/commit/099469502f62fbe0d7e4f0b83a2f22538367f734 -- Pavel > Why this option was placed under expert? > > What is the value of disabling this functionality ever? > > Is there any reason why we don't just delete CONFIG_CHECKPOINT_RESTORE > entirely? > > Certainly we are at a point where distro's are enabling this so hiding > it behind CONFIG_EXPERT with a default of N seems inapparopriate. > > The only thing I can imagine might be sensible is changing the default > to Y and leaving it behind CONFIG_EXPERT. > > I want to know what is the point of maintaining all of the complexity of > the ifdefs. If no one can come up with a reason I say let's just remove > CONFIG_CHECKPOINT_RESTORE entirely. > > Eric > > >> Signed-off-by: Adrian Reber <adr...@lisas.de> >> Cc: Oleg Nesterov <o...@redhat.com> >> Cc: Pavel Emelyanov <xe...@virtuozzo.com> >> Cc: Andrew Morton <a...@linux-foundation.org> >> Cc: Eric W. Biederman <ebied...@xmission.com> >> Cc: Andrei Vagin <ava...@virtuozzo.com> >> Cc: Hendrik Brueckner <brueck...@linux.vnet.ibm.com> >> --- >> init/Kconfig | 24 ++++++++++++------------ >> 1 file changed, 12 insertions(+), 12 deletions(-) >> >> diff --git a/init/Kconfig b/init/Kconfig >> index 041f3a022122..9c529c763326 100644 >> --- a/init/Kconfig >> +++ b/init/Kconfig >> @@ -932,6 +932,18 @@ config NET_NS >> >> endif # NAMESPACES >> >> +config CHECKPOINT_RESTORE >> + bool "Checkpoint/restore support" >> + select PROC_CHILDREN >> + default n >> + help >> + Enables additional kernel features in a sake of checkpoint/restore. >> + In particular it adds auxiliary prctl codes to setup process text, >> + data and heap segment sizes, and a few additional /proc filesystem >> + entries. >> + >> + If unsure, say N here. >> + >> config SCHED_AUTOGROUP >> bool "Automatic process group scheduling" >> select CGROUPS >> @@ -1348,18 +1360,6 @@ config MEMBARRIER >> >> If unsure, say Y. >> >> -config CHECKPOINT_RESTORE >> - bool "Checkpoint/restore support" if EXPERT >> - select PROC_CHILDREN >> - default n >> - help >> - Enables additional kernel features in a sake of checkpoint/restore. >> - In particular it adds auxiliary prctl codes to setup process text, >> - data and heap segment sizes, and a few additional /proc filesystem >> - entries. >> - >> - If unsure, say N here. >> - >> config KALLSYMS >> bool "Load all symbols for debugging/ksymoops" if EXPERT >> default y > . >
