From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f197.google.com (mail-pg1-f197.google.com [209.85.215.197]) by kanga.kvack.org (Postfix) with ESMTP id EBC906B7E28 for ; Fri, 7 Sep 2018 07:43:55 -0400 (EDT) Received: by mail-pg1-f197.google.com with SMTP id g5-v6so7163730pgq.5 for ; Fri, 07 Sep 2018 04:43:55 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id g16-v6sor1378994pgg.427.2018.09.07.04.43.54 for (Google Transport Security); Fri, 07 Sep 2018 04:43:54 -0700 (PDT) From: Michal Hocko Subject: [RFC PATCH] mm, page_alloc: drop should_suppress_show_mem Date: Fri, 7 Sep 2018 13:43:34 +0200 Message-Id: <20180907114334.7088-1-mhocko@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: Vlastimil Babka , Andrew Morton , David Rientjes , Mel Gorman , LKML , Michal Hocko From: Michal Hocko should_suppress_show_mem has been introduced to reduce the overhead of show_mem on large NUMA systems. Things have changed since then though. Namely c78e93630d15 ("mm: do not walk all of system memory during show_mem") has reduced the overhead considerably. Moreover warn_alloc_show_mem clears SHOW_MEM_FILTER_NODES when called from the IRQ context already so we are not printing per node stats. Remove should_suppress_show_mem because we are losing potentially interesting information about allocation failures. We have seen a bug report where system gets unresponsive under memory pressure and there is only kernel: [2032243.696888] qlge 0000:8b:00.1 ql1: Could not get a page chunk, i=8, clean_idx =200 . kernel: [2032243.710725] swapper/7: page allocation failure: order:1, mode:0x1084120(GFP_ATOMIC|__GFP_COLD|__GFP_COMP) without an additional information for debugging. It would be great to see the state of the page allocator at the moment. Signed-off-by: Michal Hocko --- mm/page_alloc.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 89d2a2ab3fe6..025f23dc282e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3366,26 +3366,12 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, return NULL; } -/* - * Large machines with many possible nodes should not always dump per-node - * meminfo in irq context. - */ -static inline bool should_suppress_show_mem(void) -{ - bool ret = false; - -#if NODES_SHIFT > 8 - ret = in_interrupt(); -#endif - return ret; -} - static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask) { unsigned int filter = SHOW_MEM_FILTER_NODES; static DEFINE_RATELIMIT_STATE(show_mem_rs, HZ, 1); - if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs)) + if (!__ratelimit(&show_mem_rs)) return; /* -- 2.18.0