From d656a447893dccc310c975a239f482278550c3e0 Mon Sep 17 00:00:00 2001 From: Jan Stancek Date: Tue, 21 May 2019 10:10:44 +0200 Subject: [PATCH] overcommit_memory: update for "mm: fix false-positive OVERCOMMIT_GUESS failures" commit 8c7829b04c52 ("mm: fix false-positive OVERCOMMIT_GUESS failures") changes logic of __vm_enough_memory(), simplifying it to: When in GUESS mode, catch wild allocations by comparing their request size to total amount of ram and swap in the system. Testcase currently allocates mem_total + swap_total, which doesn't trigger new condition. Make it more extreme, but assuming free_total / 2 will PASS, and 2*sum_total will FAIL. Signed-off-by: Jan Stancek Acked-by: Cyril Hrubis Upstream-Status: Backport [https://github.com/linux-test-project/ltp/commit/d656a447893dccc310c975a239f482278550c3e0] Signed-off-by: He Zhe --- testcases/kernel/mem/tunable/overcommit_memory.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/testcases/kernel/mem/tunable/overcommit_memory.c b/testcases/kernel/mem/tunable/overcommit_memory.c index 555298f..345764d 100644 --- a/testcases/kernel/mem/tunable/overcommit_memory.c +++ b/testcases/kernel/mem/tunable/overcommit_memory.c @@ -36,11 +36,10 @@ * * The program is designed to test the two tunables: * - * When overcommit_memory = 0, allocatable memory can't overextends - * the amount of free memory. I choose the three cases: + * When overcommit_memory = 0, allocatable memory can't overextend + * the amount of total memory: * a. less than free_total: free_total / 2, alloc should pass. - * b. greater than free_total: free_total * 2, alloc should fail. - * c. equal to sum_total: sum_tatal, alloc should fail + * b. greater than sum_total: sum_total * 2, alloc should fail. * * When overcommit_memory = 1, it can alloc enough much memory, I * choose the three cases: @@ -164,9 +163,7 @@ static void overcommit_memory_test(void) update_mem(); alloc_and_check(free_total / 2, EXPECT_PASS); - update_mem(); - alloc_and_check(free_total * 2, EXPECT_FAIL); - alloc_and_check(sum_total, EXPECT_FAIL); + alloc_and_check(sum_total * 2, EXPECT_FAIL); /* start to test overcommit_memory=1 */ set_sys_tune("overcommit_memory", 1, 1); -- 2.7.4