Re: [PATCH v1 1/5] mm/memory_hotplug: check for fatal signals only in offline_pages()

From: Michal Hocko
Date: Tue Jun 27 2023 - 08:35:05 EST


On Tue 27-06-23 13:22:16, David Hildenbrand wrote:
> Let's check for fatal signals only. That looks cleaner and still keeps
> the documented use case for manual user-space triggered memory offlining
> working. From Documentation/admin-guide/mm/memory-hotplug.rst:
>
> % timeout $TIMEOUT offline_block | failure_handling
>
> In fact, we even document there: "the offlining context can be terminated
> by sending a fatal signal".

We should be fixing documentation instead. This could break users who do
have a SIGALRM signal hander installed.

> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
> mm/memory_hotplug.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 8e0fa209d533..0d2151df4ee1 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1879,7 +1879,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages,
> do {
> pfn = start_pfn;
> do {
> - if (signal_pending(current)) {
> + if (fatal_signal_pending(current)) {
> ret = -EINTR;
> reason = "signal backoff";
> goto failed_removal_isolated;
> --
> 2.40.1

--
Michal Hocko
SUSE Labs