| Message ID | 20230222232058.66971-1-vernon2gm@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/slub: fix help comment of SLUB_DEBUG[_ON] | expand |
On Thu, Feb 23, 2023 at 07:20:58AM +0800, Vernon Yang wrote: > Since commit 081248de0a02 ("kset: move /sys/slab to /sys/kernel/slab"), > the SYSFS path of slab was modified, so fix up the help comment of > SLUB_DEBUG to use the correct one. > > And now the "slub_debug" parameter on boot that is support for more > fine grained debug control, so fix up help comment of SLUB_DEBUG_ON > for "no support" to "support". > > Signed-off-by: Vernon Yang <vernon2gm@gmail.com> > --- > mm/Kconfig.debug | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug > index fca699ad1fb0..732043bf56c6 100644 > --- a/mm/Kconfig.debug > +++ b/mm/Kconfig.debug > @@ -61,8 +61,8 @@ config SLUB_DEBUG > help > SLUB has extensive debug support features. Disabling these can > result in significant savings in code size. This also disables > - SLUB sysfs support. /sys/slab will not exist and there will be > - no support for cache validation etc. > + SLUB sysfs support. /sys/kernel/slab will not exist and there > + will be no support for cache validation etc. After commit ab4d5ed5eeda ("slub: Enable sysfs support for !CONFIG_SLUB_DEBUG"), "Disabling SLUB_DEBUG also disables SLUB sysfs support" is not true anymore. > config SLUB_DEBUG_ON > bool "SLUB debugging on by default" > @@ -73,10 +73,10 @@ config SLUB_DEBUG_ON > Boot with debugging on by default. SLUB boots by default with > the runtime debug capabilities switched off. Enabling this is > equivalent to specifying the "slub_debug" parameter on boot. > - There is no support for more fine grained debug control like > - possible with slub_debug=xxx. SLUB debugging may be switched > - off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying > - "slub_debug=-". > + There is support for more fine grained debug control like > + possible with slub_debug=xxx, details in Documentation/mm/slub.rst. > + SLUB debugging may be switched off in a kernel built with > + CONFIG_SLUB_DEBUG_ON by specifying "slub_debug=-". I think this is a misunderstanding. SLUB_DEBUG_ON is equivalent to passing boot parameter slub_debug=FUPZ, and what the help text says is that "You can enable slub debugging by default using this config option but there is no support for fine-grained control like what slub_debug boot parameter provides." IOW SLUB_DEBUG_ON cannot be used to have same effect as passing something like slub_debug=F. > > config PAGE_OWNER > bool "Track page owner" > -- > 2.34.1 > >
On 2/23/23 02:03, Hyeonggon Yoo wrote: > On Thu, Feb 23, 2023 at 07:20:58AM +0800, Vernon Yang wrote: >> Since commit 081248de0a02 ("kset: move /sys/slab to /sys/kernel/slab"), >> the SYSFS path of slab was modified, so fix up the help comment of >> SLUB_DEBUG to use the correct one. >> >> And now the "slub_debug" parameter on boot that is support for more >> fine grained debug control, so fix up help comment of SLUB_DEBUG_ON >> for "no support" to "support". >> >> Signed-off-by: Vernon Yang <vernon2gm@gmail.com> >> --- >> mm/Kconfig.debug | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug >> index fca699ad1fb0..732043bf56c6 100644 >> --- a/mm/Kconfig.debug >> +++ b/mm/Kconfig.debug >> @@ -61,8 +61,8 @@ config SLUB_DEBUG >> help >> SLUB has extensive debug support features. Disabling these can >> result in significant savings in code size. This also disables >> - SLUB sysfs support. /sys/slab will not exist and there will be >> - no support for cache validation etc. >> + SLUB sysfs support. /sys/kernel/slab will not exist and there >> + will be no support for cache validation etc. > > After commit ab4d5ed5eeda ("slub: Enable sysfs support for !CONFIG_SLUB_DEBUG"), > "Disabling SLUB_DEBUG also disables SLUB sysfs support" is not true anymore. Yeah we could say that /sys/kernel/slab will exist but will not provide e.g. cache validation. >> config SLUB_DEBUG_ON >> bool "SLUB debugging on by default" >> @@ -73,10 +73,10 @@ config SLUB_DEBUG_ON >> Boot with debugging on by default. SLUB boots by default with >> the runtime debug capabilities switched off. Enabling this is >> equivalent to specifying the "slub_debug" parameter on boot. >> - There is no support for more fine grained debug control like >> - possible with slub_debug=xxx. SLUB debugging may be switched >> - off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying >> - "slub_debug=-". >> + There is support for more fine grained debug control like >> + possible with slub_debug=xxx, details in Documentation/mm/slub.rst. >> + SLUB debugging may be switched off in a kernel built with >> + CONFIG_SLUB_DEBUG_ON by specifying "slub_debug=-". > > I think this is a misunderstanding. SLUB_DEBUG_ON is equivalent to > passing boot parameter slub_debug=FUPZ, and what the help text says is that > > "You can enable slub debugging by default using this config option but > there is no support for fine-grained control like what slub_debug > boot parameter provides." > > IOW SLUB_DEBUG_ON cannot be used to have same effect as passing > something like slub_debug=F. Agree with both comments. Vernon, will you send an updated patch? >> >> config PAGE_OWNER >> bool "Track page owner" >> -- >> 2.34.1 >> >>
On Mon, Mar 13, 2023 at 05:26:19PM +0100, Vlastimil Babka wrote: > On 2/23/23 02:03, Hyeonggon Yoo wrote: > > On Thu, Feb 23, 2023 at 07:20:58AM +0800, Vernon Yang wrote: > >> Since commit 081248de0a02 ("kset: move /sys/slab to /sys/kernel/slab"), > >> the SYSFS path of slab was modified, so fix up the help comment of > >> SLUB_DEBUG to use the correct one. > >> > >> And now the "slub_debug" parameter on boot that is support for more > >> fine grained debug control, so fix up help comment of SLUB_DEBUG_ON > >> for "no support" to "support". > >> > >> Signed-off-by: Vernon Yang <vernon2gm@gmail.com> > >> --- > >> mm/Kconfig.debug | 12 ++++++------ > >> 1 file changed, 6 insertions(+), 6 deletions(-) > >> > >> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug > >> index fca699ad1fb0..732043bf56c6 100644 > >> --- a/mm/Kconfig.debug > >> +++ b/mm/Kconfig.debug > >> @@ -61,8 +61,8 @@ config SLUB_DEBUG > >> help > >> SLUB has extensive debug support features. Disabling these can > >> result in significant savings in code size. This also disables > >> - SLUB sysfs support. /sys/slab will not exist and there will be > >> - no support for cache validation etc. > >> + SLUB sysfs support. /sys/kernel/slab will not exist and there > >> + will be no support for cache validation etc. > > > > After commit ab4d5ed5eeda ("slub: Enable sysfs support for !CONFIG_SLUB_DEBUG"), > > "Disabling SLUB_DEBUG also disables SLUB sysfs support" is not true anymore. Yes, You are right. Thanks. > > Yeah we could say that /sys/kernel/slab will exist but will not provide e.g. > cache validation. OK. > > >> config SLUB_DEBUG_ON > >> bool "SLUB debugging on by default" > >> @@ -73,10 +73,10 @@ config SLUB_DEBUG_ON > >> Boot with debugging on by default. SLUB boots by default with > >> the runtime debug capabilities switched off. Enabling this is > >> equivalent to specifying the "slub_debug" parameter on boot. > >> - There is no support for more fine grained debug control like > >> - possible with slub_debug=xxx. SLUB debugging may be switched > >> - off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying > >> - "slub_debug=-". > >> + There is support for more fine grained debug control like > >> + possible with slub_debug=xxx, details in Documentation/mm/slub.rst. > >> + SLUB debugging may be switched off in a kernel built with > >> + CONFIG_SLUB_DEBUG_ON by specifying "slub_debug=-". > > > > I think this is a misunderstanding. SLUB_DEBUG_ON is equivalent to Yeah, This is a misunderstanding. I remove this. > > passing boot parameter slub_debug=FUPZ, and what the help text says is that > > > > "You can enable slub debugging by default using this config option but > > there is no support for fine-grained control like what slub_debug > > boot parameter provides." > > > > IOW SLUB_DEBUG_ON cannot be used to have same effect as passing > > something like slub_debug=F. > > Agree with both comments. Vernon, will you send an updated patch? Ok, I'll be sending a new patch shortly. > > >> > >> config PAGE_OWNER > >> bool "Track page owner" > >> -- > >> 2.34.1 > >> > >> >
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index fca699ad1fb0..732043bf56c6 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -61,8 +61,8 @@ config SLUB_DEBUG help SLUB has extensive debug support features. Disabling these can result in significant savings in code size. This also disables - SLUB sysfs support. /sys/slab will not exist and there will be - no support for cache validation etc. + SLUB sysfs support. /sys/kernel/slab will not exist and there + will be no support for cache validation etc. config SLUB_DEBUG_ON bool "SLUB debugging on by default" @@ -73,10 +73,10 @@ config SLUB_DEBUG_ON Boot with debugging on by default. SLUB boots by default with the runtime debug capabilities switched off. Enabling this is equivalent to specifying the "slub_debug" parameter on boot. - There is no support for more fine grained debug control like - possible with slub_debug=xxx. SLUB debugging may be switched - off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying - "slub_debug=-". + There is support for more fine grained debug control like + possible with slub_debug=xxx, details in Documentation/mm/slub.rst. + SLUB debugging may be switched off in a kernel built with + CONFIG_SLUB_DEBUG_ON by specifying "slub_debug=-". config PAGE_OWNER bool "Track page owner"
Since commit 081248de0a02 ("kset: move /sys/slab to /sys/kernel/slab"), the SYSFS path of slab was modified, so fix up the help comment of SLUB_DEBUG to use the correct one. And now the "slub_debug" parameter on boot that is support for more fine grained debug control, so fix up help comment of SLUB_DEBUG_ON for "no support" to "support". Signed-off-by: Vernon Yang <vernon2gm@gmail.com> --- mm/Kconfig.debug | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)