From patchwork Fri Feb 24 04:39:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 656355 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 530CFC6FA9D for ; Fri, 24 Feb 2023 04:41:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229479AbjBXElQ (ORCPT ); Thu, 23 Feb 2023 23:41:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229545AbjBXElN (ORCPT ); Thu, 23 Feb 2023 23:41:13 -0500 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2D994ECFE for ; Thu, 23 Feb 2023 20:41:10 -0800 (PST) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 05A317B74EDA; Thu, 23 Feb 2023 20:40:59 -0800 (PST) From: Stefan Roesch To: kernel-team@fb.com Cc: shr@devkernel.io, linux-mm@kvack.org, riel@surriel.com, mhocko@suse.com, david@redhat.com, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, akpm@linux-foundation.org, hannes@cmpxchg.org Subject: [PATCH v3 1/3] mm: add new api to enable ksm per process Date: Thu, 23 Feb 2023 20:39:58 -0800 Message-Id: <20230224044000.3084046-2-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230224044000.3084046-1-shr@devkernel.io> References: <20230224044000.3084046-1-shr@devkernel.io> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This adds a new prctl to API to enable and disable KSM on a per process basis instead of only at the VMA basis (with madvise). 1) Introduce new MMF_VM_MERGE_ANY flag This introduces the new flag MMF_VM_MERGE_ANY flag. When this flag is set, kernel samepage merging (ksm) gets enabled for all vma's of a process. 2) add flag to __ksm_enter This change adds the flag parameter to __ksm_enter. This allows to distinguish if ksm was called by prctl or madvise. 3) add flag to __ksm_exit call This adds the flag parameter to the __ksm_exit() call. This allows to distinguish if this call is for an prctl or madvise invocation. 4) invoke madvise for all vmas in scan_get_next_rmap_item If the new flag MMF_VM_MERGE_ANY has been set for a process, iterate over all the vmas and enable ksm if possible. For the vmas that can be ksm enabled this is only done once. 5) support disabling of ksm for a process This adds the ability to disable ksm for a process if ksm has been enabled for the process. 6) add new prctl option to get and set ksm for a process This adds two new options to the prctl system call - enable ksm for all vmas of a process (if the vmas support it). - query if ksm has been enabled for a process. Signed-off-by: Stefan Roesch --- include/linux/ksm.h | 14 ++++--- include/linux/sched/coredump.h | 1 + include/uapi/linux/prctl.h | 2 + kernel/sys.c | 29 +++++++++++++++ mm/ksm.c | 67 ++++++++++++++++++++++++++++++---- 5 files changed, 101 insertions(+), 12 deletions(-) diff --git a/include/linux/ksm.h b/include/linux/ksm.h index 7e232ba59b86..d38a05a36298 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -18,20 +18,24 @@ #ifdef CONFIG_KSM int ksm_madvise(struct vm_area_struct *vma, unsigned long start, unsigned long end, int advice, unsigned long *vm_flags); -int __ksm_enter(struct mm_struct *mm); -void __ksm_exit(struct mm_struct *mm); +int __ksm_enter(struct mm_struct *mm, int flag); +void __ksm_exit(struct mm_struct *mm, int flag); static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) { + if (test_bit(MMF_VM_MERGE_ANY, &oldmm->flags)) + return __ksm_enter(mm, MMF_VM_MERGE_ANY); if (test_bit(MMF_VM_MERGEABLE, &oldmm->flags)) - return __ksm_enter(mm); + return __ksm_enter(mm, MMF_VM_MERGEABLE); return 0; } static inline void ksm_exit(struct mm_struct *mm) { - if (test_bit(MMF_VM_MERGEABLE, &mm->flags)) - __ksm_exit(mm); + if (test_bit(MMF_VM_MERGE_ANY, &mm->flags)) + __ksm_exit(mm, MMF_VM_MERGE_ANY); + else if (test_bit(MMF_VM_MERGEABLE, &mm->flags)) + __ksm_exit(mm, MMF_VM_MERGEABLE); } /* diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h index 0e17ae7fbfd3..0ee96ea7a0e9 100644 --- a/include/linux/sched/coredump.h +++ b/include/linux/sched/coredump.h @@ -90,4 +90,5 @@ static inline int get_dumpable(struct mm_struct *mm) #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK) +#define MMF_VM_MERGE_ANY 29 #endif /* _LINUX_SCHED_COREDUMP_H */ diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index 1312a137f7fb..759b3f53e53f 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -290,4 +290,6 @@ struct prctl_mm_map { #define PR_SET_VMA 0x53564d41 # define PR_SET_VMA_ANON_NAME 0 +#define PR_SET_MEMORY_MERGE 67 +#define PR_GET_MEMORY_MERGE 68 #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/sys.c b/kernel/sys.c index b3cab94545ed..495bab3ed2ad 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -2659,6 +2660,34 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, case PR_SET_VMA: error = prctl_set_vma(arg2, arg3, arg4, arg5); break; +#ifdef CONFIG_KSM + case PR_SET_MEMORY_MERGE: + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + + if (arg2) { + if (mmap_write_lock_killable(me->mm)) + return -EINTR; + + if (test_bit(MMF_VM_MERGEABLE, &me->mm->flags)) + error = -EINVAL; + else if (!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags)) + error = __ksm_enter(me->mm, MMF_VM_MERGE_ANY); + mmap_write_unlock(me->mm); + } else { + __ksm_exit(me->mm, MMF_VM_MERGE_ANY); + } + break; + case PR_GET_MEMORY_MERGE: + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + + if (arg2 || arg3 || arg4 || arg5) + return -EINVAL; + + error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags); + break; +#endif default: error = -EINVAL; break; diff --git a/mm/ksm.c b/mm/ksm.c index 56808e3bfd19..23d6944f78ad 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1063,6 +1063,7 @@ static int unmerge_and_remove_all_rmap_items(void) mm_slot_free(mm_slot_cache, mm_slot); clear_bit(MMF_VM_MERGEABLE, &mm->flags); + clear_bit(MMF_VM_MERGE_ANY, &mm->flags); mmdrop(mm); } else spin_unlock(&ksm_mmlist_lock); @@ -2329,6 +2330,17 @@ static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot, return rmap_item; } +static bool vma_ksm_mergeable(struct vm_area_struct *vma) +{ + if (vma->vm_flags & VM_MERGEABLE) + return true; + + if (test_bit(MMF_VM_MERGE_ANY, &vma->vm_mm->flags)) + return true; + + return false; +} + static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page) { struct mm_struct *mm; @@ -2405,8 +2417,20 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page) goto no_vmas; for_each_vma(vmi, vma) { - if (!(vma->vm_flags & VM_MERGEABLE)) + if (!vma_ksm_mergeable(vma)) continue; + if (!(vma->vm_flags & VM_MERGEABLE)) { + unsigned long flags = vma->vm_flags; + + /* madvise failed, use next vma */ + if (ksm_madvise(vma, vma->vm_start, vma->vm_end, MADV_MERGEABLE, &flags)) + continue; + /* vma, not supported as being mergeable */ + if (!(flags & VM_MERGEABLE)) + continue; + + vm_flags_set(vma, VM_MERGEABLE); + } if (ksm_scan.address < vma->vm_start) ksm_scan.address = vma->vm_start; if (!vma->anon_vma) @@ -2491,6 +2515,7 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page) mm_slot_free(mm_slot_cache, mm_slot); clear_bit(MMF_VM_MERGEABLE, &mm->flags); + clear_bit(MMF_VM_MERGE_ANY, &mm->flags); mmap_read_unlock(mm); mmdrop(mm); } else { @@ -2595,8 +2620,9 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, return 0; #endif - if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) { - err = __ksm_enter(mm); + if (!test_bit(MMF_VM_MERGEABLE, &mm->flags) && + !test_bit(MMF_VM_MERGE_ANY, &mm->flags)) { + err = __ksm_enter(mm, MMF_VM_MERGEABLE); if (err) return err; } @@ -2622,7 +2648,7 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, } EXPORT_SYMBOL_GPL(ksm_madvise); -int __ksm_enter(struct mm_struct *mm) +int __ksm_enter(struct mm_struct *mm, int flag) { struct ksm_mm_slot *mm_slot; struct mm_slot *slot; @@ -2655,7 +2681,7 @@ int __ksm_enter(struct mm_struct *mm) list_add_tail(&slot->mm_node, &ksm_scan.mm_slot->slot.mm_node); spin_unlock(&ksm_mmlist_lock); - set_bit(MMF_VM_MERGEABLE, &mm->flags); + set_bit(flag, &mm->flags); mmgrab(mm); if (needs_wakeup) @@ -2664,12 +2690,39 @@ int __ksm_enter(struct mm_struct *mm) return 0; } -void __ksm_exit(struct mm_struct *mm) +static void unmerge_vmas(struct mm_struct *mm) +{ + struct vm_area_struct *vma; + struct vma_iterator vmi; + + vma_iter_init(&vmi, mm, 0); + + mmap_read_lock(mm); + for_each_vma(vmi, vma) { + if (vma->vm_flags & VM_MERGEABLE) { + unsigned long flags = vma->vm_flags; + + if (ksm_madvise(vma, vma->vm_start, vma->vm_end, MADV_UNMERGEABLE, &flags)) + continue; + + vm_flags_clear(vma, VM_MERGEABLE); + } + } + mmap_read_unlock(mm); +} + +void __ksm_exit(struct mm_struct *mm, int flag) { struct ksm_mm_slot *mm_slot; struct mm_slot *slot; int easy_to_free = 0; + if (!(current->flags & PF_EXITING) && flag == MMF_VM_MERGE_ANY && + test_bit(MMF_VM_MERGE_ANY, &mm->flags)) { + clear_bit(MMF_VM_MERGE_ANY, &mm->flags); + unmerge_vmas(mm); + } + /* * This process is exiting: if it's straightforward (as is the * case when ksmd was never running), free mm_slot immediately. @@ -2696,7 +2749,7 @@ void __ksm_exit(struct mm_struct *mm) if (easy_to_free) { mm_slot_free(mm_slot_cache, mm_slot); - clear_bit(MMF_VM_MERGEABLE, &mm->flags); + clear_bit(flag, &mm->flags); mmdrop(mm); } else if (mm_slot) { mmap_write_lock(mm); From patchwork Fri Feb 24 04:40:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 656354 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 644CFC6FD18 for ; Fri, 24 Feb 2023 04:41:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229611AbjBXElR (ORCPT ); Thu, 23 Feb 2023 23:41:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229672AbjBXElQ (ORCPT ); Thu, 23 Feb 2023 23:41:16 -0500 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCC285EECD for ; Thu, 23 Feb 2023 20:41:13 -0800 (PST) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 0FAE87B74EDF; Thu, 23 Feb 2023 20:40:59 -0800 (PST) From: Stefan Roesch To: kernel-team@fb.com Cc: shr@devkernel.io, linux-mm@kvack.org, riel@surriel.com, mhocko@suse.com, david@redhat.com, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, akpm@linux-foundation.org, hannes@cmpxchg.org Subject: [PATCH v3 3/3] selftests/mm: add new selftests for KSM Date: Thu, 23 Feb 2023 20:40:00 -0800 Message-Id: <20230224044000.3084046-4-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230224044000.3084046-1-shr@devkernel.io> References: <20230224044000.3084046-1-shr@devkernel.io> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This adds three new tests to the selftests for KSM. These tests use the new prctl API's to enable and disable KSM. 1) add new prctl flags to prctl header file in tools dir This adds the new prctl flags to the include file prct.h in the tools directory. This makes sure they are available for testing. 2) add KSM prctl merge test This adds the -t option to the ksm_tests program. The -t flag allows to specify if it should use madvise or prctl ksm merging. 3) add KSM get merge type test This adds the -G flag to the ksm_tests program to query the KSM status with prctl after KSM has been enabled with prctl. 4) add KSM fork test Add fork test to verify that the MMF_VM_MERGE_ANY flag is inherited by the child process. 5) add two functions for debugging merge outcome This adds two functions to report the metrics in /proc/self/ksm_stat and /sys/kernel/debug/mm/ksm. The debugging can be enabled with the following command line: make -C tools/testing/selftests TARGETS="vm" --keep-going \ EXTRA_CFLAGS=-DDEBUG=1 Signed-off-by: Stefan Roesch --- tools/include/uapi/linux/prctl.h | 2 + tools/testing/selftests/mm/Makefile | 3 +- tools/testing/selftests/mm/ksm_tests.c | 254 +++++++++++++++++++++---- 3 files changed, 219 insertions(+), 40 deletions(-) diff --git a/tools/include/uapi/linux/prctl.h b/tools/include/uapi/linux/prctl.h index a5e06dcbba13..e4c629c1f1b0 100644 --- a/tools/include/uapi/linux/prctl.h +++ b/tools/include/uapi/linux/prctl.h @@ -284,4 +284,6 @@ struct prctl_mm_map { #define PR_SET_VMA 0x53564d41 # define PR_SET_VMA_ANON_NAME 0 +#define PR_SET_MEMORY_MERGE 67 +#define PR_GET_MEMORY_MERGE 68 #endif /* _LINUX_PRCTL_H */ diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index d90cdc06aa59..507cb22bdebd 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -29,7 +29,8 @@ MACHINE ?= $(shell echo $(uname_M) | sed -e 's/aarch64.*/arm64/' -e 's/ppc64.*/p # LDLIBS. MAKEFLAGS += --no-builtin-rules -CFLAGS = -Wall -I $(top_srcdir) -I $(top_srcdir)/usr/include $(EXTRA_CFLAGS) $(KHDR_INCLUDES) +CFLAGS = -Wall -I $(top_srcdir)/tools/include/uapi +CFLAGS += -I $(top_srcdir) -I $(top_srcdir)/usr/include $(EXTRA_CFLAGS) $(KHDR_INCLUDES) LDLIBS = -lrt -lpthread TEST_GEN_FILES = cow TEST_GEN_FILES += compaction_test diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c index f9eb4d67e0dd..9fb21b982dc9 100644 --- a/tools/testing/selftests/mm/ksm_tests.c +++ b/tools/testing/selftests/mm/ksm_tests.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include +#include #include #include #include @@ -21,6 +23,7 @@ #define KSM_PROT_STR_DEFAULT "rw" #define KSM_USE_ZERO_PAGES_DEFAULT false #define KSM_MERGE_ACROSS_NODES_DEFAULT true +#define KSM_MERGE_TYPE_DEFAULT 0 #define MB (1ul << 20) struct ksm_sysfs { @@ -33,9 +36,17 @@ struct ksm_sysfs { unsigned long use_zero_pages; }; +enum ksm_merge_type { + KSM_MERGE_MADVISE, + KSM_MERGE_PRCTL, + KSM_MERGE_LAST = KSM_MERGE_PRCTL +}; + enum ksm_test_name { CHECK_KSM_MERGE, + CHECK_KSM_MERGE_FORK, CHECK_KSM_UNMERGE, + CHECK_KSM_GET_MERGE_TYPE, CHECK_KSM_ZERO_PAGE_MERGE, CHECK_KSM_NUMA_MERGE, KSM_MERGE_TIME, @@ -82,6 +93,55 @@ static int ksm_read_sysfs(const char *file_path, unsigned long *val) return 0; } +#ifdef DEBUG +static void ksm_print_sysfs(void) +{ + unsigned long max_page_sharing, pages_sharing, pages_shared; + unsigned long full_scans, pages_unshared, pages_volatile; + unsigned long stable_node_chains, stable_node_dups; + long general_profit; + + if (ksm_read_sysfs(KSM_FP("pages_shared"), &pages_shared) || + ksm_read_sysfs(KSM_FP("pages_sharing"), &pages_sharing) || + ksm_read_sysfs(KSM_FP("max_page_sharing"), &max_page_sharing) || + ksm_read_sysfs(KSM_FP("full_scans"), &full_scans) || + ksm_read_sysfs(KSM_FP("pages_unshared"), &pages_unshared) || + ksm_read_sysfs(KSM_FP("pages_volatile"), &pages_volatile) || + ksm_read_sysfs(KSM_FP("stable_node_chains"), &stable_node_chains) || + ksm_read_sysfs(KSM_FP("stable_node_dups"), &stable_node_dups) || + ksm_read_sysfs(KSM_FP("general_profit"), (unsigned long *)&general_profit)) + return; + + printf("pages_shared : %lu\n", pages_shared); + printf("pages_sharing : %lu\n", pages_sharing); + printf("max_page_sharing : %lu\n", max_page_sharing); + printf("full_scans : %lu\n", full_scans); + printf("pages_unshared : %lu\n", pages_unshared); + printf("pages_volatile : %lu\n", pages_volatile); + printf("stable_node_chains: %lu\n", stable_node_chains); + printf("stable_node_dups : %lu\n", stable_node_dups); + printf("general_profit : %ld\n", general_profit); +} + +static void ksm_print_procfs(void) +{ + const char *file_name = "/proc/self/ksm_stat"; + char buffer[512]; + FILE *f = fopen(file_name, "r"); + + if (!f) { + fprintf(stderr, "f %s\n", file_name); + perror("fopen"); + return; + } + + while (fgets(buffer, sizeof(buffer), f)) + printf("%s", buffer); + + fclose(f); +} +#endif + static int str_to_prot(char *prot_str) { int prot = 0; @@ -115,7 +175,9 @@ static void print_help(void) " -D evaluate unmerging time and speed when disabling KSM.\n" " For this test, the size of duplicated memory area (in MiB)\n" " must be provided using -s option\n" - " -C evaluate the time required to break COW of merged pages.\n\n"); + " -C evaluate the time required to break COW of merged pages.\n" + " -G query merge mode\n" + " -F evaluate that the KSM process flag is inherited\n\n"); printf(" -a: specify the access protections of pages.\n" " must be of the form [rwx].\n" @@ -129,6 +191,10 @@ static void print_help(void) printf(" -m: change merge_across_nodes tunable\n" " Default: %d\n", KSM_MERGE_ACROSS_NODES_DEFAULT); printf(" -s: the size of duplicated memory area (in MiB)\n"); + printf(" -t: KSM merge type\n" + " Default: 0\n" + " 0: madvise merging\n" + " 1: prctl merging\n"); exit(0); } @@ -176,12 +242,21 @@ static int ksm_do_scan(int scan_count, struct timespec start_time, int timeout) return 0; } -static int ksm_merge_pages(void *addr, size_t size, struct timespec start_time, int timeout) +static int ksm_merge_pages(int merge_type, void *addr, size_t size, + struct timespec start_time, int timeout) { - if (madvise(addr, size, MADV_MERGEABLE)) { - perror("madvise"); - return 1; + if (merge_type == KSM_MERGE_MADVISE) { + if (madvise(addr, size, MADV_MERGEABLE)) { + perror("madvise"); + return 1; + } + } else if (merge_type == KSM_MERGE_PRCTL) { + if (prctl(PR_SET_MEMORY_MERGE, 1)) { + perror("prctl"); + return 1; + } } + if (ksm_write_sysfs(KSM_FP("run"), 1)) return 1; @@ -211,6 +286,11 @@ static bool assert_ksm_pages_count(long dupl_page_count) ksm_read_sysfs(KSM_FP("max_page_sharing"), &max_page_sharing)) return false; +#ifdef DEBUG + ksm_print_sysfs(); + ksm_print_procfs(); +#endif + /* * Since there must be at least 2 pages for merging and 1 page can be * shared with the limited number of pages (max_page_sharing), sometimes @@ -266,7 +346,8 @@ static int ksm_restore(struct ksm_sysfs *ksm_sysfs) return 0; } -static int check_ksm_merge(int mapping, int prot, long page_count, int timeout, size_t page_size) +static int check_ksm_merge(int merge_type, int mapping, int prot, + long page_count, int timeout, size_t page_size) { void *map_ptr; struct timespec start_time; @@ -281,13 +362,16 @@ static int check_ksm_merge(int mapping, int prot, long page_count, int timeout, if (!map_ptr) return KSFT_FAIL; - if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout)) + if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout)) goto err_out; /* verify that the right number of pages are merged */ if (assert_ksm_pages_count(page_count)) { printf("OK\n"); - munmap(map_ptr, page_size * page_count); + if (merge_type == KSM_MERGE_MADVISE) + munmap(map_ptr, page_size * page_count); + else if (merge_type == KSM_MERGE_PRCTL) + prctl(PR_SET_MEMORY_MERGE, 0); return KSFT_PASS; } @@ -297,7 +381,73 @@ static int check_ksm_merge(int mapping, int prot, long page_count, int timeout, return KSFT_FAIL; } -static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_size) +/* Verify that prctl ksm flag is inherited. */ +static int check_ksm_fork(void) +{ + int rc = KSFT_FAIL; + pid_t child_pid; + + if (prctl(PR_SET_MEMORY_MERGE, 1)) { + perror("prctl"); + return KSFT_FAIL; + } + + child_pid = fork(); + if (child_pid == 0) { + int is_on = prctl(PR_GET_MEMORY_MERGE, 0); + + if (!is_on) + exit(KSFT_FAIL); + + exit(KSFT_PASS); + } + + if (child_pid < 0) + goto out; + + if (waitpid(child_pid, &rc, 0) < 0) + rc = KSFT_FAIL; + + if (prctl(PR_SET_MEMORY_MERGE, 0)) { + perror("prctl"); + rc = KSFT_FAIL; + } + +out: + if (rc == KSFT_PASS) + printf("OK\n"); + else + printf("Not OK\n"); + + return rc; +} + +static int check_ksm_get_merge_type(void) +{ + if (prctl(PR_SET_MEMORY_MERGE, 1)) { + perror("prctl set"); + return 1; + } + + int is_on = prctl(PR_GET_MEMORY_MERGE, 0); + + if (prctl(PR_SET_MEMORY_MERGE, 0)) { + perror("prctl set"); + return 1; + } + + int is_off = prctl(PR_GET_MEMORY_MERGE, 0); + + if (is_on && is_off) { + printf("OK\n"); + return KSFT_PASS; + } + + printf("Not OK\n"); + return KSFT_FAIL; +} + +static int check_ksm_unmerge(int merge_type, int mapping, int prot, int timeout, size_t page_size) { void *map_ptr; struct timespec start_time; @@ -313,7 +463,7 @@ static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_siz if (!map_ptr) return KSFT_FAIL; - if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout)) + if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout)) goto err_out; /* change 1 byte in each of the 2 pages -- KSM must automatically unmerge them */ @@ -337,8 +487,8 @@ static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_siz return KSFT_FAIL; } -static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int timeout, - bool use_zero_pages, size_t page_size) +static int check_ksm_zero_page_merge(int merge_type, int mapping, int prot, long page_count, + int timeout, bool use_zero_pages, size_t page_size) { void *map_ptr; struct timespec start_time; @@ -356,7 +506,7 @@ static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int if (!map_ptr) return KSFT_FAIL; - if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout)) + if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout)) goto err_out; /* @@ -402,8 +552,8 @@ static int get_first_mem_node(void) return get_next_mem_node(numa_max_node()); } -static int check_ksm_numa_merge(int mapping, int prot, int timeout, bool merge_across_nodes, - size_t page_size) +static int check_ksm_numa_merge(int merge_type, int mapping, int prot, int timeout, + bool merge_across_nodes, size_t page_size) { void *numa1_map_ptr, *numa2_map_ptr; struct timespec start_time; @@ -439,8 +589,8 @@ static int check_ksm_numa_merge(int mapping, int prot, int timeout, bool merge_a memset(numa2_map_ptr, '*', page_size); /* try to merge the pages */ - if (ksm_merge_pages(numa1_map_ptr, page_size, start_time, timeout) || - ksm_merge_pages(numa2_map_ptr, page_size, start_time, timeout)) + if (ksm_merge_pages(merge_type, numa1_map_ptr, page_size, start_time, timeout) || + ksm_merge_pages(merge_type, numa2_map_ptr, page_size, start_time, timeout)) goto err_out; /* @@ -466,7 +616,8 @@ static int check_ksm_numa_merge(int mapping, int prot, int timeout, bool merge_a return KSFT_FAIL; } -static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t map_size) +static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot, + int timeout, size_t map_size) { void *map_ptr, *map_ptr_orig; struct timespec start_time, end_time; @@ -508,7 +659,7 @@ static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t m perror("clock_gettime"); goto err_out; } - if (ksm_merge_pages(map_ptr, map_size, start_time, timeout)) + if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout)) goto err_out; if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) { perror("clock_gettime"); @@ -533,7 +684,7 @@ static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t m return KSFT_FAIL; } -static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size) +static int ksm_merge_time(int merge_type, int mapping, int prot, int timeout, size_t map_size) { void *map_ptr; struct timespec start_time, end_time; @@ -549,7 +700,7 @@ static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size) perror("clock_gettime"); goto err_out; } - if (ksm_merge_pages(map_ptr, map_size, start_time, timeout)) + if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout)) goto err_out; if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) { perror("clock_gettime"); @@ -574,7 +725,7 @@ static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size) return KSFT_FAIL; } -static int ksm_unmerge_time(int mapping, int prot, int timeout, size_t map_size) +static int ksm_unmerge_time(int merge_type, int mapping, int prot, int timeout, size_t map_size) { void *map_ptr; struct timespec start_time, end_time; @@ -589,7 +740,7 @@ static int ksm_unmerge_time(int mapping, int prot, int timeout, size_t map_size) perror("clock_gettime"); goto err_out; } - if (ksm_merge_pages(map_ptr, map_size, start_time, timeout)) + if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout)) goto err_out; if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) { @@ -621,7 +772,7 @@ static int ksm_unmerge_time(int mapping, int prot, int timeout, size_t map_size) return KSFT_FAIL; } -static int ksm_cow_time(int mapping, int prot, int timeout, size_t page_size) +static int ksm_cow_time(int merge_type, int mapping, int prot, int timeout, size_t page_size) { void *map_ptr; struct timespec start_time, end_time; @@ -660,7 +811,7 @@ static int ksm_cow_time(int mapping, int prot, int timeout, size_t page_size) memset(map_ptr + page_size * i, '+', i / 2 + 1); memset(map_ptr + page_size * (i + 1), '+', i / 2 + 1); } - if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout)) + if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout)) goto err_out; if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) { @@ -697,6 +848,7 @@ int main(int argc, char *argv[]) int ret, opt; int prot = 0; int ksm_scan_limit_sec = KSM_SCAN_LIMIT_SEC_DEFAULT; + int merge_type = KSM_MERGE_TYPE_DEFAULT; long page_count = KSM_PAGE_COUNT_DEFAULT; size_t page_size = sysconf(_SC_PAGESIZE); struct ksm_sysfs ksm_sysfs_old; @@ -705,7 +857,7 @@ int main(int argc, char *argv[]) bool merge_across_nodes = KSM_MERGE_ACROSS_NODES_DEFAULT; long size_MB = 0; - while ((opt = getopt(argc, argv, "ha:p:l:z:m:s:MUZNPCHD")) != -1) { + while ((opt = getopt(argc, argv, "ha:p:l:z:m:s:t:FGMUZNPCHD")) != -1) { switch (opt) { case 'a': prot = str_to_prot(optarg); @@ -745,6 +897,20 @@ int main(int argc, char *argv[]) printf("Size must be greater than 0\n"); return KSFT_FAIL; } + case 't': + { + int tmp = atoi(optarg); + + if (tmp < 0 || tmp > KSM_MERGE_LAST) { + printf("Invalid merge type\n"); + return KSFT_FAIL; + } + merge_type = atoi(optarg); + } + break; + case 'F': + test_name = CHECK_KSM_MERGE_FORK; + break; case 'M': break; case 'U': @@ -753,6 +919,9 @@ int main(int argc, char *argv[]) case 'Z': test_name = CHECK_KSM_ZERO_PAGE_MERGE; break; + case 'G': + test_name = CHECK_KSM_GET_MERGE_TYPE; + break; case 'N': test_name = CHECK_KSM_NUMA_MERGE; break; @@ -795,35 +964,42 @@ int main(int argc, char *argv[]) switch (test_name) { case CHECK_KSM_MERGE: - ret = check_ksm_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, + ret = check_ksm_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, ksm_scan_limit_sec, page_size); break; + case CHECK_KSM_MERGE_FORK: + ret = check_ksm_fork(); + break; case CHECK_KSM_UNMERGE: - ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, - page_size); + ret = check_ksm_unmerge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, + ksm_scan_limit_sec, page_size); + break; + case CHECK_KSM_GET_MERGE_TYPE: + ret = check_ksm_get_merge_type(); break; case CHECK_KSM_ZERO_PAGE_MERGE: - ret = check_ksm_zero_page_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, - ksm_scan_limit_sec, use_zero_pages, page_size); + ret = check_ksm_zero_page_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, + page_count, ksm_scan_limit_sec, use_zero_pages, + page_size); break; case CHECK_KSM_NUMA_MERGE: - ret = check_ksm_numa_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, - merge_across_nodes, page_size); + ret = check_ksm_numa_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, + ksm_scan_limit_sec, merge_across_nodes, page_size); break; case KSM_MERGE_TIME: if (size_MB == 0) { printf("Option '-s' is required.\n"); return KSFT_FAIL; } - ret = ksm_merge_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, - size_MB); + ret = ksm_merge_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, + ksm_scan_limit_sec, size_MB); break; case KSM_MERGE_TIME_HUGE_PAGES: if (size_MB == 0) { printf("Option '-s' is required.\n"); return KSFT_FAIL; } - ret = ksm_merge_hugepages_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, + ret = ksm_merge_hugepages_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, size_MB); break; case KSM_UNMERGE_TIME: @@ -831,12 +1007,12 @@ int main(int argc, char *argv[]) printf("Option '-s' is required.\n"); return KSFT_FAIL; } - ret = ksm_unmerge_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, + ret = ksm_unmerge_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, size_MB); break; case KSM_COW_TIME: - ret = ksm_cow_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, - page_size); + ret = ksm_cow_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, + ksm_scan_limit_sec, page_size); break; }