On Thu, Oct 12, 2023 at 12:37 PM Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
On Thu, Oct 12, 2023 at 12:26:58PM +0200, Greg Kroah-Hartman wrote:
On Thu, Oct 12, 2023 at 10:40:14AM +0200, Alexander Potapenko wrote:
On Thu, Oct 12, 2023 at 10:17 AM Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
In commit efb78fa86e95 ("lib/test_meminit: allocate pages up to order MAX_ORDER"), the loop for testing pages is set to "<= MAX_ORDER" which causes crashes in systems when run. Fix this to "< MAX_ORDER" to fix the test to work properly.
What are the crashes you are seeing? Are those OOMs?
They are WARN_ON() triggers. They are burried in the Android build system, let me see if I can uncover them.
IIUC it should be valid to allocate with MAX_ORDER.
"should", but I no longer get runtime warnings with this patch applied, so something is wrong :)
I think I know what's going on. In March 2023 Kirill changed the semantics of MAX_ORDER to be inclusive: now alloc_pages() accepts 0..MAX_ORDER, whereas previously it was 0..MAX_ORDER-1: https://github.com/torvalds/linux/commit/23baf831a32c04f9a968812511540b1b3e6... Older kernel versions had an explicit check for order >= MAX_ORDER, which is what you're seeing on Android.