From patchwork Mon Jan 23 17:37:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13112638 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 91615C25B50 for ; Mon, 23 Jan 2023 17:38:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B3F046B0080; Mon, 23 Jan 2023 12:38:17 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AED376B0081; Mon, 23 Jan 2023 12:38:17 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 945026B0082; Mon, 23 Jan 2023 12:38:17 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 6EBA26B0081 for ; 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dkim=none; spf=neutral (imf04.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1674495495; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Q+yy9dVQzb3LP9jKQiRsz9lchW7Eo0LuwsAlK7jS7SI=; b=6aeXpERvJYZ4kIi8HnMGFDeakgHA+DCqsJlSGJ790z6j52Xs4E/661QFKKgP7L848xn1Qn tXtZ4Y4lZF9BIfEMpIjbensfXKAA0NLENk7CI9eZRmvRha+Il8ZSIS/evgu1x8KyGJrfL4 /xQdvi7eG0BL1q1TO/8kBfCIblisJtk= Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 5D2035616BDF; Mon, 23 Jan 2023 09:37:56 -0800 (PST) From: Stefan Roesch To: linux-mm@kvack.org Cc: shr@devkernel.io, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [RESEND RFC PATCH v1 07/20] mm: add tracepoints to ksm Date: Mon, 23 Jan 2023 09:37:35 -0800 Message-Id: <20230123173748.1734238-8-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230123173748.1734238-1-shr@devkernel.io> References: <20230123173748.1734238-1-shr@devkernel.io> MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Queue-Id: 852E740021 X-Rspamd-Server: rspam01 X-Stat-Signature: qdreewxisxfz43ions378kjoex7kckkm X-HE-Tag: 1674495495-860636 X-HE-Meta: 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 S1Mu5bJD czqHDtC8F7ClXbqRWDPz5azsrigofH+2inRQ3bdoe9aaWJns= 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 following tracepoints to ksm: - start / stop scan - ksm enter / exit - merge a page - merge a page with ksm - remove a page - remove a rmap item Signed-off-by: Stefan Roesch Reviewed-by: Steven Rostedt (Google) --- MAINTAINERS | 1 + include/trace/events/ksm.h | 257 +++++++++++++++++++++++++++++++++++++ mm/ksm.c | 20 ++- 3 files changed, 276 insertions(+), 2 deletions(-) create mode 100644 include/trace/events/ksm.h diff --git a/MAINTAINERS b/MAINTAINERS index 123216b76534..990a28bdc263 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13482,6 +13482,7 @@ F: include/linux/memory_hotplug.h F: include/linux/mm.h F: include/linux/mmzone.h F: include/linux/pagewalk.h +F: include/trace/events/ksm.h F: mm/ F: tools/testing/selftests/vm/ diff --git a/include/trace/events/ksm.h b/include/trace/events/ksm.h new file mode 100644 index 000000000000..727d8f6dbc3f --- /dev/null +++ b/include/trace/events/ksm.h @@ -0,0 +1,257 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM ksm + +#if !defined(_TRACE_KSM_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_KSM_H + +#include + +/** + * ksm_scan_template - called for start / stop scan + * + * @seq: sequence number of scan + * @rmap_entries: actual number of rmap entries + * + * Allows to trace the start / stop of a ksm scan. + */ +DECLARE_EVENT_CLASS(ksm_scan_template, + + TP_PROTO(int seq, u32 rmap_entries), + + TP_ARGS(seq, rmap_entries), + + TP_STRUCT__entry( + __field(int, seq) + __field(u32, rmap_entries) + ), + + TP_fast_assign( + __entry->seq = seq; + __entry->rmap_entries = rmap_entries; + ), + + TP_printk("seq %d rmap size %d", + __entry->seq, __entry->rmap_entries) +); + +/** + * ksm_start_scan - called after a new ksm scan is started + * + * @seq: sequence number of scan + * @rmap_entries: actual number of rmap entries + * + * Allows to trace the start of a ksm scan. + */ +DEFINE_EVENT(ksm_scan_template, ksm_start_scan, + + TP_PROTO(int seq, u32 rmap_entries), + + TP_ARGS(seq, rmap_entries) +); + +/** + * ksm_stop_scan - called after a new ksm scan has completed + * + * @seq: sequence number of scan + * @rmap_entries: actual number of rmap entries + * + * Allows to trace the completion of a ksm scan. + */ +DEFINE_EVENT(ksm_scan_template, ksm_stop_scan, + + TP_PROTO(int seq, u32 rmap_entries), + + TP_ARGS(seq, rmap_entries) +); + +/** + * ksm_enter - called after a new process has been added / removed from ksm + * + * @mm: address of the mm object of the process + * @flag: specified flags + * + * Allows to trace the when a process has been added or removed from ksm. + */ +DECLARE_EVENT_CLASS(ksm_enter_exit_template, + + TP_PROTO(void *mm, unsigned int flag), + + TP_ARGS(mm, flag), + + TP_STRUCT__entry( + __field(void *, mm) + __field(unsigned int, flag) + ), + + TP_fast_assign( + __entry->mm = mm; + __entry->flag = flag; + ), + + TP_printk("mm %p flag %u", + __entry->mm, __entry->flag) +); + +/** + * ksm_enter - called after a new process has been added to ksm + * + * @mm: address of the mm object of the process + * @flag: specified flags + * + * Allows to trace the when a process has been added to ksm. + */ +DEFINE_EVENT(ksm_enter_exit_template, ksm_enter, + + TP_PROTO(void *mm, unsigned int flag), + + TP_ARGS(mm, flag) +); + +/** + * ksm_exit - called after a new process has been removed from ksm + * + * @mm: address of the mm object of the process + * @flag: specified flags + * + * Allows to trace the when a process has been removed from ksm. + */ +DEFINE_EVENT(ksm_enter_exit_template, ksm_exit, + + TP_PROTO(void *mm, unsigned int flag), + + TP_ARGS(mm, flag) +); + +/** + * ksm_merge_one_page - called after a page has been merged + * + * @pfn: page frame number of ksm page + * @rmap_item: address of rmap_item object + * @mm: address of the process mm struct + * @err: success + * + * Allows to trace the ksm merging of individual pages. + */ +TRACE_EVENT(ksm_merge_one_page, + + TP_PROTO(unsigned long pfn, void *rmap_item, void *mm, int err), + + TP_ARGS(pfn, rmap_item, mm, err), + + TP_STRUCT__entry( + __field(unsigned long, pfn) + __field(void *, rmap_item) + __field(void *, mm) + __field(int, err) + ), + + TP_fast_assign( + __entry->pfn = pfn; + __entry->rmap_item = rmap_item; + __entry->mm = mm; + __entry->err = err; + ), + + TP_printk("ksm pfn %lu rmap_item %p mm %p error %d", + __entry->pfn, __entry->rmap_item, __entry->mm, __entry->err) +); + +/** + * ksm_merge_with_ksm_page - called after a page has been merged with a ksm page + * + * @ksm_page: address ksm page + * @pfn: page frame number of ksm page + * @rmap_item: address of rmap_item object + * @mm: address of the mm object of the process + * @err: success + * + * Allows to trace the merging of a page with a ksm page. + */ +TRACE_EVENT(ksm_merge_with_ksm_page, + + TP_PROTO(void *ksm_page, unsigned long pfn, void *rmap_item, void *mm, int err), + + TP_ARGS(ksm_page, pfn, rmap_item, mm, err), + + TP_STRUCT__entry( + __field(void *, ksm_page) + __field(unsigned long, pfn) + __field(void *, rmap_item) + __field(void *, mm) + __field(int, err) + ), + + TP_fast_assign( + __entry->ksm_page = ksm_page; + __entry->pfn = pfn; + __entry->rmap_item = rmap_item; + __entry->mm = mm; + __entry->err = err; + ), + + TP_printk("%spfn %lu rmap_item %p mm %p error %d", + (__entry->ksm_page ? "ksm " : ""), + __entry->pfn, __entry->rmap_item, __entry->mm, __entry->err) +); + +/** + * ksm_remove_ksm_page - called after a ksm page has been removed + * + * @pfn: page frame number of ksm page + * + * Allows to trace the removing of stable ksm pages. + */ +TRACE_EVENT(ksm_remove_ksm_page, + + TP_PROTO(unsigned long pfn), + + TP_ARGS(pfn), + + TP_STRUCT__entry( + __field(unsigned long, pfn) + ), + + TP_fast_assign( + __entry->pfn = pfn; + ), + + TP_printk("pfn %lu", __entry->pfn) +); + +/** + * ksm_remove_rmap_item - called after a rmap_item has been removed from the + * stable tree + * + * @pfn: page frame number of ksm page + * @rmap_item: address of rmap_item object + * @mm: address of the process mm struct + * + * Allows to trace the removal of pages from the stable tree list. + */ +TRACE_EVENT(ksm_remove_rmap_item, + + TP_PROTO(unsigned long pfn, void *rmap_item, void *mm), + + TP_ARGS(pfn, rmap_item, mm), + + TP_STRUCT__entry( + __field(unsigned long, pfn) + __field(void *, rmap_item) + __field(void *, mm) + ), + + TP_fast_assign( + __entry->pfn = pfn; + __entry->rmap_item = rmap_item; + __entry->mm = mm; + ), + + TP_printk("pfn %lu rmap_item %p mm %p", + __entry->pfn, __entry->rmap_item, __entry->mm) +); + +#endif /* _TRACE_KSM_H */ + +/* This part must be outside protection */ +#include diff --git a/mm/ksm.c b/mm/ksm.c index 5fa6b46dfa3b..88a969849955 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -45,6 +45,9 @@ #include "internal.h" #include "mm_slot.h" +#define CREATE_TRACE_POINTS +#include + #ifdef CONFIG_NUMA #define NUMA(x) (x) #define DO_NUMA(x) do { (x); } while (0) @@ -633,10 +636,12 @@ static void remove_node_from_stable_tree(struct ksm_stable_node *stable_node) BUG_ON(stable_node->rmap_hlist_len < 0); hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) { - if (rmap_item->hlist.next) + if (rmap_item->hlist.next) { + trace_ksm_remove_rmap_item(stable_node->kpfn, rmap_item, rmap_item->mm); ksm_pages_sharing--; - else + } else { ksm_pages_shared--; + } rmap_item->mm->ksm_merging_pages--; @@ -657,6 +662,7 @@ static void remove_node_from_stable_tree(struct ksm_stable_node *stable_node) BUILD_BUG_ON(STABLE_NODE_DUP_HEAD <= &migrate_nodes); BUILD_BUG_ON(STABLE_NODE_DUP_HEAD >= &migrate_nodes + 1); + trace_ksm_remove_ksm_page(stable_node->kpfn); if (stable_node->head == &migrate_nodes) list_del(&stable_node->list); else @@ -1319,6 +1325,8 @@ static int try_to_merge_with_ksm_page(struct ksm_rmap_item *rmap_item, get_anon_vma(vma->anon_vma); out: mmap_read_unlock(mm); + trace_ksm_merge_with_ksm_page(kpage, page_to_pfn(kpage ? kpage : page), + rmap_item, mm, err); return err; } @@ -2137,6 +2145,8 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite if (vma) { err = try_to_merge_one_page(vma, page, ZERO_PAGE(rmap_item->address)); + trace_ksm_merge_one_page(page_to_pfn(ZERO_PAGE(rmap_item->address)), + rmap_item, mm, err); } else { /* * If the vma is out of date, we do not need to @@ -2270,6 +2280,8 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page) mm_slot = ksm_scan.mm_slot; if (mm_slot == &ksm_mm_head) { + trace_ksm_start_scan(ksm_scan.seqnr, ksm_rmap_items); + /* * A number of pages can hang around indefinitely on per-cpu * pagevecs, raised page count preventing write_protect_page @@ -2433,6 +2445,7 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page) if (mm_slot != &ksm_mm_head) goto next_mm; + trace_ksm_stop_scan(ksm_scan.seqnr, ksm_rmap_items); ksm_scan.seqnr++; return NULL; } @@ -2585,6 +2598,7 @@ int __ksm_enter(struct mm_struct *mm, int flag) if (needs_wakeup) wake_up_interruptible(&ksm_thread_wait); + trace_ksm_enter(mm, flag); return 0; } @@ -2653,6 +2667,8 @@ void __ksm_exit(struct mm_struct *mm, int flag) mmap_write_lock(mm); mmap_write_unlock(mm); } + + trace_ksm_exit(mm, flag); } struct page *ksm_might_need_to_copy(struct page *page,