On Thu, Mar 13, 2025 at 04:46:36PM +0100, Joel Granados wrote: > After writing "4" to /proc/sys/vm/drop_caches there was no way to > re-enable the drop_caches kernel message. By removing the "or" logic for > the stfu variable in drop_cache_sysctl_handler, it is now possible to > toggle the message on and off by setting the 4th bit in > /proc/sys/vm/drop_caches. > > Signed-off-by: Joel Granados <joel.granados@xxxxxxxxxx> > --- > Documentation/admin-guide/sysctl/vm.rst | 2 +- > fs/drop_caches.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst > index f48eaa98d22d2b575f6e913f437b0d548daac3e6..75a032f8cbfb4e05f04610cca219d154bd852789 100644 > --- a/Documentation/admin-guide/sysctl/vm.rst > +++ b/Documentation/admin-guide/sysctl/vm.rst > @@ -266,7 +266,7 @@ used:: > cat (1234): drop_caches: 3 > > These are informational only. They do not mean that anything is wrong > -with your system. To disable them, echo 4 (bit 2) into drop_caches. > +with your system. To toggle them, echo 4 (bit 2) into drop_caches. > > enable_soft_offline > =================== > diff --git a/fs/drop_caches.c b/fs/drop_caches.c > index d45ef541d848a73cbd19205e0111c2cab3b73617..501b9f690445e245f88cbb31a5123b2752e2e7ce 100644 > --- a/fs/drop_caches.c > +++ b/fs/drop_caches.c > @@ -73,7 +73,7 @@ int drop_caches_sysctl_handler(const struct ctl_table *table, int write, > current->comm, task_pid_nr(current), > sysctl_drop_caches); > } > - stfu |= sysctl_drop_caches & 4; > + stfu = sysctl_drop_caches & 4; > } > return 0; > } > > --- > base-commit: 7eb172143d5508b4da468ed59ee857c6e5e01da6 > change-id: 20250313-jag-drop_caches_msg-c4fbfedb51f3 > > Best regards, > -- > Joel Granados <joel.granados@xxxxxxxxxx> > > In case you are curious: This is a V3 of what was discussed in https://lore.kernel.org/20250216100514.3948-1-rwchen404@xxxxxxxxx My bad for forgetting to tag it V3 :(. Best -- Joel Granados
