From 839195352d8235072dcaac054b2e26b2dd2213e5 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 6 Aug 2020 23:25:38 -0700 Subject: mm/shuffle: remove dynamic reconfiguration Commit e900a918b098 ("mm: shuffle initial free memory to improve memory-side-cache utilization") promised "autodetection of a memory-side-cache (to be added in a follow-on patch)" over a year ago. The original series included patches [1], however, they were dropped during review [2] to be followed-up later. Due to lack of platforms that publish an HMAT, autodetection is currently not implemented. However, manual activation is actively used [3]. Let's simplify for now and re-add when really (ever?) needed. [1] https://lkml.kernel.org/r/154510700291.1941238.817190985966612531.stgit@dwillia2-desk3.amr.corp.intel.com [2] https://lkml.kernel.org/r/154690326478.676627.103843791978176914.stgit@dwillia2-desk3.amr.corp.intel.com [3] https://lkml.kernel.org/r/CAPcyv4irwGUU2x+c6b4L=KbB1dnasNKaaZd6oSpYjL9kfsnROQ@mail.gmail.com Signed-off-by: David Hildenbrand Signed-off-by: Andrew Morton Reviewed-by: Wei Yang Acked-by: Dan Williams Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Michal Hocko Cc: Minchan Kim Cc: Huang Ying Cc: Wei Yang Cc: Mel Gorman Cc: Dan Williams Link: http://lkml.kernel.org/r/20200624094741.9918-4-david@redhat.com Signed-off-by: Linus Torvalds --- mm/shuffle.c | 28 ++-------------------------- 1 file changed, 2 insertions(+), 26 deletions(-) (limited to 'mm/shuffle.c') diff --git a/mm/shuffle.c b/mm/shuffle.c index dd13ab851b3e..9b5cd4b004b0 100644 --- a/mm/shuffle.c +++ b/mm/shuffle.c @@ -10,33 +10,11 @@ #include "shuffle.h" DEFINE_STATIC_KEY_FALSE(page_alloc_shuffle_key); -static unsigned long shuffle_state __ro_after_init; - -/* - * Depending on the architecture, module parameter parsing may run - * before, or after the cache detection. SHUFFLE_FORCE_DISABLE prevents, - * or reverts the enabling of the shuffle implementation. SHUFFLE_ENABLE - * attempts to turn on the implementation, but aborts if it finds - * SHUFFLE_FORCE_DISABLE already set. - */ -__meminit void page_alloc_shuffle(enum mm_shuffle_ctl ctl) -{ - if (ctl == SHUFFLE_FORCE_DISABLE) - set_bit(SHUFFLE_FORCE_DISABLE, &shuffle_state); - - if (test_bit(SHUFFLE_FORCE_DISABLE, &shuffle_state)) { - if (test_and_clear_bit(SHUFFLE_ENABLE, &shuffle_state)) - static_branch_disable(&page_alloc_shuffle_key); - } else if (ctl == SHUFFLE_ENABLE - && !test_and_set_bit(SHUFFLE_ENABLE, &shuffle_state)) - static_branch_enable(&page_alloc_shuffle_key); -} static bool shuffle_param; static int shuffle_show(char *buffer, const struct kernel_param *kp) { - return sprintf(buffer, "%c\n", test_bit(SHUFFLE_ENABLE, &shuffle_state) - ? 'Y' : 'N'); + return sprintf(buffer, "%c\n", shuffle_param ? 'Y' : 'N'); } static __meminit int shuffle_store(const char *val, @@ -47,9 +25,7 @@ static __meminit int shuffle_store(const char *val, if (rc < 0) return rc; if (shuffle_param) - page_alloc_shuffle(SHUFFLE_ENABLE); - else - page_alloc_shuffle(SHUFFLE_FORCE_DISABLE); + static_branch_enable(&page_alloc_shuffle_key); return 0; } module_param_call(shuffle, shuffle_store, shuffle_show, &shuffle_param, 0400); -- cgit v1.2.3