On Fri, 1 Mar 2019 09:25:24 +0100 Guillaume Tucker <guillaume.tucker@xxxxxxxxxxxxx> wrote: > >>> Michal had asked if the free space accounting fix up addressed this > >>> boot regression? I was awaiting word on that. > >> > >> hm, does bot@xxxxxxxxxxxx actually read emails? Let's try info@ as well.. > > bot@xxxxxxxxxxxx is not person, it's a send-only account for > automated reports. So no, it doesn't read emails. > > I guess the tricky point here is that the authors of the commits > found by bisections may not always have the hardware needed to > reproduce the problem. So it needs to be dealt with on a > case-by-case basis: sometimes they do have the hardware, > sometimes someone else on the list or on CC does, and sometimes > it's better for the people who have access to the test lab which > ran the KernelCI test to deal with it. > > This case seems to fall into the last category. As I have access > to the Collabora lab, I can do some quick checks to confirm > whether the proposed patch does fix the issue. I hadn't realised > that someone was waiting for this to happen, especially as the > BeagleBone Black is a very common platform. Sorry about that, > I'll take a look today. > > It may be a nice feature to be able to give access to the > KernelCI test infrastructure to anyone who wants to debug an > issue reported by KernelCI or verify a fix, so they won't need to > have the hardware locally. Something to think about for the > future. Thanks, that all sounds good. > >> Is it possible to determine whether this regression is still present in > >> current linux-next? > > I'll try to re-apply the patch that caused the issue, then see if > the suggested change fixes it. As far as the current linux-next > master branch is concerned, KernelCI boot tests are passing fine > on that platform. They would, because I dropped mm-shuffle-default-enable-all-shuffling.patch, so your tests presumably now have shuffling disabled. Is it possible to add the below to linux-next and try again? Or I can re-add this to linux-next. Where should we go to determine the results of such a change? There are a heck of a lot of results on https://kernelci.org/boot/ and entering "beaglebone-black" doesn't get me anything. Thanks. From: Dan Williams <dan.j.williams@xxxxxxxxx> Subject: mm/shuffle: default enable all shuffling Per Andrew's request arrange for all memory allocation shuffling code to be enabled by default. The page_alloc.shuffle command line parameter can still be used to disable shuffling at boot, but the kernel will default enable the shuffling if the command line option is not specified. Link: http://lkml.kernel.org/r/154943713572.3858443.11206307988382889377.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Keith Busch <keith.busch@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- init/Kconfig | 4 ++-- mm/shuffle.c | 4 ++-- mm/shuffle.h | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) --- a/init/Kconfig~mm-shuffle-default-enable-all-shuffling +++ a/init/Kconfig @@ -1709,7 +1709,7 @@ config SLAB_MERGE_DEFAULT command line. config SLAB_FREELIST_RANDOM - default n + default y depends on SLAB || SLUB bool "SLAB freelist randomization" help @@ -1728,7 +1728,7 @@ config SLAB_FREELIST_HARDENED config SHUFFLE_PAGE_ALLOCATOR bool "Page allocator randomization" - default SLAB_FREELIST_RANDOM && ACPI_NUMA + default y help Randomization of the page allocator improves the average utilization of a direct-mapped memory-side-cache. See section --- a/mm/shuffle.c~mm-shuffle-default-enable-all-shuffling +++ a/mm/shuffle.c @@ -9,8 +9,8 @@ #include "internal.h" #include "shuffle.h" -DEFINE_STATIC_KEY_FALSE(page_alloc_shuffle_key); -static unsigned long shuffle_state __ro_after_init; +DEFINE_STATIC_KEY_TRUE(page_alloc_shuffle_key); +static unsigned long shuffle_state __ro_after_init = 1 << SHUFFLE_ENABLE; /* * Depending on the architecture, module parameter parsing may run --- a/mm/shuffle.h~mm-shuffle-default-enable-all-shuffling +++ a/mm/shuffle.h @@ -19,7 +19,7 @@ enum mm_shuffle_ctl { #define SHUFFLE_ORDER (MAX_ORDER-1) #ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR -DECLARE_STATIC_KEY_FALSE(page_alloc_shuffle_key); +DECLARE_STATIC_KEY_TRUE(page_alloc_shuffle_key); extern void page_alloc_shuffle(enum mm_shuffle_ctl ctl); extern void __shuffle_free_memory(pg_data_t *pgdat); static inline void shuffle_free_memory(pg_data_t *pgdat) _
