From patchwork Fri Mar 10 18:28:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13169942 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62D95C74A44 for ; Fri, 10 Mar 2023 18:31:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A7DAD6B0074; Fri, 10 Mar 2023 13:31:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A38966B0075; Fri, 10 Mar 2023 13:31:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8CCFD6B0078; Fri, 10 Mar 2023 13:31:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 7D6D96B0074 for ; 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bh=ceG105YU1L2nVQtIaOOOknC1LeJqXxsUskpgONt+wRI=; b=7tiPlAG3Sbd9UtqBZSs3Der/SQsZIm0Sauk9ewZgnUulh0uU1fok8MQKM5DiDyZ7Gygyne sa3hX8mAcEOpozS4ObA9lBT7kWOWGdKidCm7aTz+1ya+tXKjJRpXouad6PljdgG5UtlqVr MlicuJastkBVbn5/iHSDhbeYn8G13FE= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf07.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1678473099; a=rsa-sha256; cv=none; b=y1rO7k0ZbQpl7K9QagiVHw3eChUfE4ICQ7DxGHMo8yTRCNwW7pPcWsk2PUa+L6IwK7+/FW G+TLVKrIZ4a0a99lZwh3JrMNOcUmbF+tB4tIzW2ZcRWVXB6EOnHZDV9Ya4JglBCVhXKlML 8G50mL3zMn2DNXo+Y0mNYoMSNJsR3Pg= Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 2280A8D84921; Fri, 10 Mar 2023 10:28:54 -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, Bagas Sanjaya Subject: [PATCH v4 1/3] mm: add new api to enable ksm per process Date: Fri, 10 Mar 2023 10:28:49 -0800 Message-Id: <20230310182851.2579138-2-shr@devkernel.io> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230310182851.2579138-1-shr@devkernel.io> References: <20230310182851.2579138-1-shr@devkernel.io> MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 5B3A940007 X-Stat-Signature: phgy6x3zznjdkiibry3utgnhzpqgznus X-HE-Tag: 1678473099-327653 X-HE-Meta: U2FsdGVkX1/7TmQ2GVQJcRmmsoBEDJ5DH+lrBOisrkR8UFGIyysSKtW6Vjt3pIbiJVjAUuoKjBl7LM1YQOGPE15/16908Ihp01VtxSlhlW8sb4t0sNMMQKQF+XYed35IXEA3ABD8WDiPGB5GK1A65aw6jibF/sumKKf29w/+MifqugMYGyQHdC9P0QI6bdahjRGRsnIJ7f+7TlmzfrowV3Ee4P4lVfPtEhlFVYpqss/98536n4+7UnDY/A/oC8zUBf17b0J5QXtd5v1oAZ1/7R+65TJcyPSH6Zzx5XSku09+c3up9KhLNpI46OMnDSMcfRzrEfkwdTuGvLzHgY8oozPvRxDqQI8njl5u+ZsVJ6/ll1ugpLGBmPLc180aUGBXs9fEFXgr3xGbjHzz8ToYNkK/KaT6DnERsA62VY0uduiVC1QY+nK99zoZIGcJCtjvffobHPID/3WrBsGXF0A1vNX+GhaLk7xqSC7+oigB2RWPjCzsXn34c/51lgl9u5EWsMTyHnawJURDoK4V6DGkQjDOwYOUuq0YSyMcgYM2f/ZUVOLqW6VP2zuVfckdIEWaJHv0tq1Dj9P9Mq3v91pOdX6Em4KNiL+9w4otSSXulMLd5IjoX0u/E6q31cUTVtn+GmAkF4RiPI5poihuT0U0lLzLTqTcIsIVpEmgtYsxyQv+QdOVA+FVpsnCVUIAy5FPwXUYZQv31/HfEKrhNqeESBDv2lP0adasLWrHdsmbiJJODfXVy1m3lbABiXqKbYAkyYW74sEGCPjtIarDo+TeSE+tpVrg6BeGnOzNfE6q7DzItouQ2fswMY8RXdzW0GQb/ZLwpp6DW0FVt3/ogWniujIaKYrmEJaUEZCFrwVhyaPCHTOr9B0QMwNKN/Yk/dbB1OF2ZgaxKuk+ac81MqYEUG7ZYZenqILRYy9m6mStkW62tdzbBnyHRoB9aNife9eZVx5OXEVYcq1SDne6m9B SImCgqCE lmmpJlNmNK1uKxm1mIW+zyUWCgv310q1DW3HE8BNIEZp5MsCjtva8W/d4KIHVcSIgXKZTLqExtSGh3qI1JuuxeuHRIc2ZtWkK+BAG9y90DR+EnbLRQXOR/ozYpG5NyEtG5Eg51eP0yAQmSzU5YH1V2+LfHWEBCoiK1Qzdo05hD++LquXTSZlxkHDgl3sOFt+06N6pW2N+dtoJkDkZwKF/ICPYHRerJ3xQB54PAXmXUkT1+707wkpxxhegRb53xcbHGkWmI0HRy+yiVWusj4AkjjXb6pNzGPkBeQBxNzd7AKVLCvSQ4QrxUjGqMtiYeYaZIMcFKXtCPxblg0jjD0VhpEZCPIE+ujPFLuHsLUk76rwq17tMkMCFYaCskzC9qbsafNo3QCckrczuFNs= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Patch series "mm: process/cgroup ksm support", v3. So far KSM can only be enabled by calling madvise for memory regions. To be able to use KSM for more workloads, KSM needs to have the ability to be enabled / disabled at the process / cgroup level. Use case 1: The madvise call is not available in the programming language. An example for this are programs with forked workloads using a garbage collected language without pointers. In such a language madvise cannot be made available. In addition the addresses of objects get moved around as they are garbage collected. KSM sharing needs to be enabled "from the outside" for these type of workloads. Use case 2: The same interpreter can also be used for workloads where KSM brings no benefit or even has overhead. We'd like to be able to enable KSM on a workload by workload basis. Use case 3: With the madvise call sharing opportunities are only enabled for the current process: it is a workload-local decision. A considerable number of sharing opportuniites may exist across multiple workloads or jobs. Only a higler level entity like a job scheduler or container can know for certain if its running one or more instances of a job. That job scheduler however doesn't have the necessary internal worklaod knowledge to make targeted madvise calls. Security concerns: In previous discussions security concerns have been brought up. The problem is that an individual workload does not have the knowledge about what else is running on a machine. Therefore it has to be very conservative in what memory areas can be shared or not. However, if the system is dedicated to running multiple jobs within the same security domain, its the job scheduler that has the knowledge that sharing can be safely enabled and is even desirable. Performance: Experiments with using UKSM have shown a capacity increase of around 20%. 1. New options for prctl system command This patch series adds two new options to the prctl system call. The first one allows to enable KSM at the process level and the second one to query the setting. The setting will be inherited by child processes. With the above setting, KSM can be enabled for the seed process of a cgroup and all processes in the cgroup will inherit the setting. 2. Changes to KSM processing When KSM is enabled at the process level, the KSM code will iterate over all the VMA's and enable KSM for the eligible VMA's. When forking a process that has KSM enabled, the setting will be inherited by the new child process. In addition when KSM is disabled for a process, KSM will be disabled for the VMA's where KSM has been enabled. 3. Add general_profit metric The general_profit metric of KSM is specified in the documentation, but not calculated. This adds the general profit metric to /sys/kernel/debug/mm/ksm. 4. Add more metrics to ksm_stat This adds the process profit and ksm type metric to /proc//ksm_stat. 5. Add more tests to ksm_tests This adds an option to specify the merge type to the ksm_tests. This allows to test madvise and prctl KSM. It also adds a new option to query if prctl KSM has been enabled. It adds a fork test to verify that the KSM process setting is inherited by client processes. An update to the prctl(2) manpage has been proposed at [1]. This patch (of 3): 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. Link: https://lkml.kernel.org/r/20230227220206.436662-1-shr@devkernel.io [1] Link: https://lkml.kernel.org/r/20230224044000.3084046-1-shr@devkernel.io Link: https://lkml.kernel.org/r/20230224044000.3084046-2-shr@devkernel.io Signed-off-by: Stefan Roesch Cc: David Hildenbrand Cc: Johannes Weiner Cc: Michal Hocko Cc: Rik van Riel Cc: Bagas Sanjaya Signed-off-by: Andrew Morton --- include/linux/ksm.h | 14 ++++-- include/linux/sched/coredump.h | 1 + include/uapi/linux/prctl.h | 2 + kernel/sys.c | 27 ++++++++++ mm/ksm.c | 90 +++++++++++++++++++++++----------- 5 files changed, 101 insertions(+), 33 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 495cd87d9bf4..edc439b1cae9 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -2661,6 +2662,32 @@ 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_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 d7bd28199f6c..b8e6e734dd69 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -534,16 +534,58 @@ static int break_ksm(struct vm_area_struct *vma, unsigned long addr, return (ret & VM_FAULT_OOM) ? -ENOMEM : 0; } +static bool vma_ksm_compatible(struct vm_area_struct *vma) +{ + /* + * Be somewhat over-protective for now! + */ + if (vma->vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE | + VM_PFNMAP | VM_IO | VM_DONTEXPAND | + VM_HUGETLB | VM_MIXEDMAP)) + return false; /* just ignore the advice */ + + if (vma_is_dax(vma)) + return false; + +#ifdef VM_SAO + if (*vm_flags & VM_SAO) + return false; +#endif +#ifdef VM_SPARC_ADI + if (*vm_flags & VM_SPARC_ADI) + return false; +#endif + + return true; +} + +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) && + vma_ksm_compatible(vma)) + return true; + + return false; +} + static struct vm_area_struct *find_mergeable_vma(struct mm_struct *mm, unsigned long addr) { struct vm_area_struct *vma; + if (ksm_test_exit(mm)) return NULL; + vma = vma_lookup(mm, addr); - if (!vma || !(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma) + if (!vma || !vma->anon_vma) return NULL; - return vma; + if (vma_ksm_mergeable(vma)) + return vma; + + return NULL; } static void break_cow(struct ksm_rmap_item *rmap_item) @@ -1042,7 +1084,7 @@ static int unmerge_and_remove_all_rmap_items(void) goto mm_exiting; for_each_vma(vmi, vma) { - if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma) + if (!vma_ksm_mergeable(vma) || !vma->anon_vma) continue; err = unmerge_ksm_pages(vma, vma->vm_start, vma->vm_end); @@ -1065,6 +1107,7 @@ 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); @@ -2409,8 +2452,9 @@ 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 (ksm_scan.address < vma->vm_start) ksm_scan.address = vma->vm_start; if (!vma->anon_vma) @@ -2495,6 +2539,7 @@ 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 { @@ -2579,28 +2624,12 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, switch (advice) { case MADV_MERGEABLE: - /* - * Be somewhat over-protective for now! - */ - if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE | - VM_PFNMAP | VM_IO | VM_DONTEXPAND | - VM_HUGETLB | VM_MIXEDMAP)) - return 0; /* just ignore the advice */ - - if (vma_is_dax(vma)) - return 0; - -#ifdef VM_SAO - if (*vm_flags & VM_SAO) - return 0; -#endif -#ifdef VM_SPARC_ADI - if (*vm_flags & VM_SPARC_ADI) + if (!vma_ksm_compatible(vma)) 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; } @@ -2626,7 +2655,7 @@ 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; @@ -2659,7 +2688,7 @@ 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) @@ -2668,12 +2697,17 @@ int __ksm_enter(struct mm_struct *mm) return 0; } -void __ksm_exit(struct mm_struct *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); + /* * This process is exiting: if it's straightforward (as is the * case when ksmd was never running), free mm_slot immediately. @@ -2700,7 +2734,7 @@ 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 Mar 10 18:28:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13169941 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB383C64EC4 for ; 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s=arc-20220608; d=hostedemail.com; t=1678473098; a=rsa-sha256; cv=none; b=eCzRKZNIKjC3Wn6XlB+qA/l/N3Xac0NvyWE5In12SQbSMNJYC6Y4WkSP1FyYwqpnrdM8br SUFTFp+Ox0i/Ok9EO/l8GIZBRzFIOhCw849RSVWhOfbookbK/gdsjk9nn97BGL2Qk78jND 9i/yI5ZpYbrYwV0WcYWPjotqdeMepQ4= Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 289CA8D84925; Fri, 10 Mar 2023 10:28:54 -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, Bagas Sanjaya Subject: [PATCH v4 2/3] mm: add new KSM process and sysfs knobs Date: Fri, 10 Mar 2023 10:28:50 -0800 Message-Id: <20230310182851.2579138-3-shr@devkernel.io> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230310182851.2579138-1-shr@devkernel.io> References: <20230310182851.2579138-1-shr@devkernel.io> MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: A3B562001B X-Stat-Signature: m14md49p4afi9cz7ysprb989i9a9yk8q X-HE-Tag: 1678473098-308585 X-HE-Meta: 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 2vYRhTDG wiXib8UhiY0IXYFa/FkeVfyKJZOlJVPHecHQRDe7d4+Xhyz5OjzN20MxXocegU2S5fNXZB8cAbekWp2jgkPOJ1ZiW7jNuqeiSne07nf/qXGtVzeOsg17Ysu/e1E9pFRxqeckTdsmN8t47cvezngNfRslmyXR6zL0sMlxTa5BBgVUxLTs3PpPf6EA2hVt13rzqjLxtXDuXd1WpSQsbwor1VMEpTmynjJjy2dtQzyhcR8ZYVceWYIXDS35Q2Kf8dkkJNaYERYYroMmadRHLpM2RtXxl1nfwf6mZR/VvQW/wyWD4bpankhXEITFh/vIOB66a/sJ/orLPkkq0+omTAlo2lJfQ4kxs4tqoSi9w5A/nrY3W5+k+ldzK0DX5PicUykoGb3lJEfuYjIYocd2u4YUj+u6vebxI0IqQYh4kZFvGLefqwL0lw5quesz3IKPG8z86Hz+B1q9NfzSsPJC4o1kG0DNmJbE/Lrj0Mku3 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This adds the general_profit KSM sysfs knob and the process profit metric and process merge type knobs to ksm_stat. 1) split off pages_volatile function This splits off the pages_volatile function. The next patch will use this function. 2) expose general_profit metric The documentation mentions a general profit metric, however this metric is not calculated. In addition the formula depends on the size of internal structures, which makes it more difficult for an administrator to make the calculation. Adding the metric for a better user experience. 3) document general_profit sysfs knob 4) calculate ksm process profit metric The ksm documentation mentions the process profit metric and how to calculate it. This adds the calculation of the metric. 5) add ksm_merge_type() function This adds the ksm_merge_type function. The function returns the merge type for the process. For madvise it returns "madvise", for prctl it returns "process" and otherwise it returns "none". 6) mm: expose ksm process profit metric and merge type in ksm_stat This exposes the ksm process profit metric in /proc//ksm_stat. The name of the value is ksm_merge_type. The documentation mentions the formula for the ksm process profit metric, however it does not calculate it. In addition the formula depends on the size of internal structures. So it makes sense to expose it. 7) document new procfs ksm knobs Link: https://lkml.kernel.org/r/20230224044000.3084046-3-shr@devkernel.io Signed-off-by: Stefan Roesch Reviewed-by: Bagas Sanjaya Cc: David Hildenbrand Cc: Johannes Weiner Cc: Michal Hocko Cc: Rik van Riel Signed-off-by: Andrew Morton --- Documentation/ABI/testing/sysfs-kernel-mm-ksm | 8 ++++ Documentation/admin-guide/mm/ksm.rst | 8 +++- fs/proc/base.c | 5 ++ include/linux/ksm.h | 5 ++ mm/ksm.c | 47 +++++++++++++++++-- 5 files changed, 69 insertions(+), 4 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-ksm b/Documentation/ABI/testing/sysfs-kernel-mm-ksm index d244674a9480..7768e90f7a8f 100644 --- a/Documentation/ABI/testing/sysfs-kernel-mm-ksm +++ b/Documentation/ABI/testing/sysfs-kernel-mm-ksm @@ -51,3 +51,11 @@ Description: Control merging pages across different NUMA nodes. When it is set to 0 only pages from the same node are merged, otherwise pages from all nodes can be merged together (default). + +What: /sys/kernel/mm/ksm/general_profit +Date: January 2023 +KernelVersion: 6.1 +Contact: Linux memory management mailing list +Description: Measure how effective KSM is. + general_profit: how effective is KSM. The formula for the + calculation is in Documentation/admin-guide/mm/ksm.rst. diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst index 270560fef3b2..d2929964cd0f 100644 --- a/Documentation/admin-guide/mm/ksm.rst +++ b/Documentation/admin-guide/mm/ksm.rst @@ -157,6 +157,8 @@ stable_node_chains_prune_millisecs The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``: +general_profit + how effective is KSM. The calculation is explained below. pages_shared how many shared pages are being used pages_sharing @@ -214,7 +216,8 @@ several times, which are unprofitable memory consumed. ksm_rmap_items * sizeof(rmap_item). where ksm_merging_pages is shown under the directory ``/proc//``, - and ksm_rmap_items is shown in ``/proc//ksm_stat``. + and ksm_rmap_items is shown in ``/proc//ksm_stat``. The process profit + is also shown in ``/proc//ksm_stat`` as ksm_process_profit. From the perspective of application, a high ratio of ``ksm_rmap_items`` to ``ksm_merging_pages`` means a bad madvise-applied policy, so developers or @@ -225,6 +228,9 @@ so if the ``ksm_rmap_items/ksm_merging_pages`` ratio exceeds 64 on 64-bit CPU or exceeds 128 on 32-bit CPU, then the app's madvise policy should be dropped, because the ksm profit is approximately zero or negative. +The ksm_merge_type in ``/proc//ksm_stat`` shows the merge type of the +process. Valid values are ``none``, ``madvise`` and ``process``. + Monitoring KSM events ===================== diff --git a/fs/proc/base.c b/fs/proc/base.c index 07463ad4a70a..c74450318e05 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -96,6 +96,7 @@ #include #include #include +#include #include #include "internal.h" #include "fd.h" @@ -3199,6 +3200,7 @@ static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace * return 0; } + static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { @@ -3208,6 +3210,9 @@ static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns, if (mm) { seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items); seq_printf(m, "zero_pages_sharing %lu\n", mm->ksm_zero_pages_sharing); + seq_printf(m, "ksm_merging_pages %lu\n", mm->ksm_merging_pages); + seq_printf(m, "ksm_merge_type %s\n", ksm_merge_type(mm)); + seq_printf(m, "ksm_process_profit %ld\n", ksm_process_profit(mm)); mmput(mm); } diff --git a/include/linux/ksm.h b/include/linux/ksm.h index d38a05a36298..d5f69f18ee5a 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -55,6 +55,11 @@ struct page *ksm_might_need_to_copy(struct page *page, void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc); void folio_migrate_ksm(struct folio *newfolio, struct folio *folio); +#ifdef CONFIG_PROC_FS +long ksm_process_profit(struct mm_struct *); +const char *ksm_merge_type(struct mm_struct *mm); +#endif /* CONFIG_PROC_FS */ + #else /* !CONFIG_KSM */ static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) diff --git a/mm/ksm.c b/mm/ksm.c index b8e6e734dd69..5fa7f239dbd8 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -3009,6 +3009,25 @@ static void wait_while_offlining(void) } #endif /* CONFIG_MEMORY_HOTREMOVE */ +#ifdef CONFIG_PROC_FS +long ksm_process_profit(struct mm_struct *mm) +{ + return (long)mm->ksm_merging_pages * PAGE_SIZE - + mm->ksm_rmap_items * sizeof(struct ksm_rmap_item); +} + +/* Return merge type name as string. */ +const char *ksm_merge_type(struct mm_struct *mm) +{ + if (test_bit(MMF_VM_MERGE_ANY, &mm->flags)) + return "process"; + else if (test_bit(MMF_VM_MERGEABLE, &mm->flags)) + return "madvise"; + else + return "none"; +} +#endif /* CONFIG_PROC_FS */ + #ifdef CONFIG_SYSFS /* * This all compiles without CONFIG_SYSFS, but is a waste of space. @@ -3256,8 +3275,7 @@ static ssize_t pages_unshared_show(struct kobject *kobj, } KSM_ATTR_RO(pages_unshared); -static ssize_t pages_volatile_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) +static long pages_volatile(void) { long ksm_pages_volatile; @@ -3269,7 +3287,14 @@ static ssize_t pages_volatile_show(struct kobject *kobj, */ if (ksm_pages_volatile < 0) ksm_pages_volatile = 0; - return sysfs_emit(buf, "%ld\n", ksm_pages_volatile); + + return ksm_pages_volatile; +} + +static ssize_t pages_volatile_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%ld\n", pages_volatile()); } KSM_ATTR_RO(pages_volatile); @@ -3280,6 +3305,21 @@ static ssize_t zero_pages_sharing_show(struct kobject *kobj, } KSM_ATTR_RO(zero_pages_sharing); +static ssize_t general_profit_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + long general_profit; + long all_rmap_items; + + all_rmap_items = ksm_max_page_sharing + ksm_pages_shared + + ksm_pages_unshared + pages_volatile(); + general_profit = ksm_pages_sharing * PAGE_SIZE - + all_rmap_items * sizeof(struct ksm_rmap_item); + + return sysfs_emit(buf, "%ld\n", general_profit); +} +KSM_ATTR_RO(general_profit); + static ssize_t stable_node_dups_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -3345,6 +3385,7 @@ static struct attribute *ksm_attrs[] = { &stable_node_dups_attr.attr, &stable_node_chains_prune_millisecs_attr.attr, &use_zero_pages_attr.attr, + &general_profit_attr.attr, NULL, }; From patchwork Fri Mar 10 18:28:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13169943 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9067AC74A4B for ; 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bh=16CXIuAh5vEbn/PS5m9R/22rJ4rHjW93M3kaX/pF6jc=; b=TqQgCTSCj7zku1h2aB3jkYtpyi4lsWF9TKZfyEm8oHyJCjHkqoPpRGBnT4Z9DXxorbqcPO gHi0vlo6bWlz5cn+Z1oOXWiKfJEUHMUBAS15wggaxMHGRG7f7JzGz9xvUEMNiOy5QOaF7t bEavhAVeXeOFQ77CoRboGQMgHS/GqTQ= Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 2F1658D84928; Fri, 10 Mar 2023 10:28:54 -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, Bagas Sanjaya Subject: [PATCH v4 3/3] selftests/mm: add new selftests for KSM Date: Fri, 10 Mar 2023 10:28:51 -0800 Message-Id: <20230310182851.2579138-4-shr@devkernel.io> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230310182851.2579138-1-shr@devkernel.io> References: <20230310182851.2579138-1-shr@devkernel.io> MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Queue-Id: AB40BC0009 X-Rspamd-Server: rspam01 X-Stat-Signature: sd6d5w7s5163ymmjwr41pdh9zbco13fn X-HE-Tag: 1678473101-603057 X-HE-Meta: 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 RLEF/L3n f5uwu3FM99q8VsBS3i4jrOVOckeGzazQ2ZoFSx/sUhaYI3MyS4jieVeSHCFG4B1TJlPDRR3K5HiqHRimohaKpEoEibxmVNLIxQ29zR0taoN0cGFkvpIJKvZ9clIEfc4Wp7gDnDnfpG9N41i3rH5N9gHTYpscp1YJZhysbSWTyXF3qODXaNgru2tPnclYQYIDEoVDSfMnuTwwHLbA0PascitIkZzktRCKYgxMcC8o/oQWhE3V5PJ0MPQC6+ggD2Ccn5tskFmE+piZrunqXc75b7xl25mNfJyGt2dul7I22gnMS+drvgqRTql26gEbd1rDte4Ovu6/kTbnP0qbmb+joTMDibamE6mf5eI43ZxIWvSk7ikxfx0o2HRmNI8OM2AK+DqZKp6UGXmKagTE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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="mm" --keep-going \ EXTRA_CFLAGS=-DDEBUG=1 [akpm@linux-foundation.org: fix Makefile] Link: https://lkml.kernel.org/r/20230224044000.3084046-4-shr@devkernel.io Signed-off-by: Stefan Roesch Cc: Bagas Sanjaya Cc: David Hildenbrand Cc: Johannes Weiner Cc: Michal Hocko Cc: Rik van Riel Signed-off-by: Andrew Morton --- tools/include/uapi/linux/prctl.h | 2 + tools/testing/selftests/mm/Makefile | 2 +- tools/testing/selftests/mm/ksm_tests.c | 254 +++++++++++++++++++++---- 3 files changed, 218 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 c31d952cff68..fbf5646b1072 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -29,7 +29,7 @@ MACHINE ?= $(shell echo $(uname_M) | sed -e 's/aarch64.*/arm64/' -e 's/ppc64.*/p # LDLIBS. MAKEFLAGS += --no-builtin-rules -CFLAGS = -Wall -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES) +CFLAGS = -Wall -I $(top_srcdir) -I $(top_srcdir)/tools/include/uapi $(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; }