Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756865Ab3DXBlp (ORCPT ); Tue, 23 Apr 2013 21:41:45 -0400 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:51618 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755606Ab3DXBli (ORCPT ); Tue, 23 Apr 2013 21:41:38 -0400 X-AuditID: 9c93016f-b7b70ae0000038d5-5d-5177384da371 From: Minchan Kim To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michael Kerrisk , Rik van Riel , Dave Hansen , Minchan Kim Subject: [PATCH v2 1/6] mm: Per process reclaim Date: Wed, 24 Apr 2013 10:40:59 +0900 Message-Id: <1366767664-17541-2-git-send-email-minchan@kernel.org> X-Mailer: git-send-email 1.8.2 In-Reply-To: <1366767664-17541-1-git-send-email-minchan@kernel.org> References: <1366767664-17541-1-git-send-email-minchan@kernel.org> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9815 Lines: 342 These day, there are many platforms avaiable in the embedded market and they are smarter than kernel which has very limited information about working set so they want to involve memory management more heavily like android's lowmemory killer and ashmem or recent many lowmemory notifier(there was several trial for various company NOKIA, SAMSUNG, Linaro, Google ChromeOS, Redhat). One of the simple imagine scenario about userspace's intelligence is that platform can manage tasks as forground and backgroud so it would be better to reclaim background's task pages for end-user's *responsibility* although it has frequent referenced pages. This patch adds new knob "reclaim under proc//" so task manager can reclaim any target process anytime, anywhere. It could give another method to platform for using memory efficiently. It can avoid process killing for getting free memory, which was really terrible experience because I lost my best score of game I had ever after I switch the phone call while I enjoyed the game. Reclaim file-backed pages only. echo file > /proc/PID/reclaim Reclaim anonymous pages only. echo anon > /proc/PID/reclaim Reclaim all pages echo all > /proc/PID/reclaim Signed-off-by: Minchan Kim --- fs/proc/base.c | 3 ++ fs/proc/internal.h | 1 + fs/proc/task_mmu.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/rmap.h | 4 ++ mm/Kconfig | 13 ++++++ mm/internal.h | 7 +-- mm/vmscan.c | 59 +++++++++++++++++++++++++ 7 files changed, 202 insertions(+), 6 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index df0dfdf..f0c8806 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2532,6 +2532,9 @@ static const struct pid_entry tgid_base_stuff[] = { REG("mounts", S_IRUGO, proc_mounts_operations), REG("mountinfo", S_IRUGO, proc_mountinfo_operations), REG("mountstats", S_IRUSR, proc_mountstats_operations), +#ifdef CONFIG_PROCESS_RECLAIM + REG("reclaim", S_IWUSR, proc_reclaim_operations), +#endif #ifdef CONFIG_PROC_PAGE_MONITOR REG("clear_refs", S_IWUSR, proc_clear_refs_operations), REG("smaps", S_IRUGO, proc_pid_smaps_operations), diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 55f3418..6ffa7cc 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -52,6 +52,7 @@ extern const struct file_operations proc_pagemap2_operations; extern const struct file_operations proc_net_operations; extern const struct inode_operations proc_net_inode_operations; extern const struct inode_operations proc_pid_link_inode_operations; +extern const struct file_operations proc_reclaim_operations; struct proc_maps_private { struct pid *pid; diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 1ec2553..fcc1c32 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -1182,6 +1183,126 @@ const struct file_operations proc_pagemap2_operations = { }; #endif /* CONFIG_PROC_PAGE_MONITOR */ +#ifdef CONFIG_PROCESS_RECLAIM +static int reclaim_pte_range(pmd_t *pmd, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct vm_area_struct *vma = walk->private; + pte_t *pte, ptent; + spinlock_t *ptl; + struct page *page; + LIST_HEAD(page_list); + int isolated; + + split_huge_page_pmd(vma, addr, pmd); + if (pmd_trans_unstable(pmd)) + return 0; +cont: + isolated = 0; + pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); + for (; addr != end; pte++, addr += PAGE_SIZE) { + ptent = *pte; + if (!pte_present(ptent)) + continue; + + page = vm_normal_page(vma, addr, ptent); + if (!page) + continue; + + if (isolate_lru_page(page)) + continue; + + list_add(&page->lru, &page_list); + inc_zone_page_state(page, NR_ISOLATED_ANON + + page_is_file_cache(page)); + isolated++; + if (isolated >= SWAP_CLUSTER_MAX) + break; + } + pte_unmap_unlock(pte - 1, ptl); + reclaim_pages_from_list(&page_list); + if (addr != end) + goto cont; + + cond_resched(); + return 0; +} + +enum reclaim_type { + RECLAIM_FILE, + RECLAIM_ANON, + RECLAIM_ALL, + RECLAIM_RANGE, +}; + +static ssize_t reclaim_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task; + char buffer[PROC_NUMBUF]; + struct mm_struct *mm; + struct vm_area_struct *vma; + enum reclaim_type type; + char *type_buf; + + memset(buffer, 0, sizeof(buffer)); + if (count > sizeof(buffer) - 1) + count = sizeof(buffer) - 1; + + if (copy_from_user(buffer, buf, count)) + return -EFAULT; + + type_buf = strstrip(buffer); + if (!strcmp(type_buf, "file")) + type = RECLAIM_FILE; + else if (!strcmp(type_buf, "anon")) + type = RECLAIM_ANON; + else if (!strcmp(type_buf, "all")) + type = RECLAIM_ALL; + else + return -EINVAL; + + task = get_proc_task(file->f_path.dentry->d_inode); + if (!task) + return -ESRCH; + + mm = get_task_mm(task); + if (mm) { + struct mm_walk reclaim_walk = { + .pmd_entry = reclaim_pte_range, + .mm = mm, + }; + + down_read(&mm->mmap_sem); + for (vma = mm->mmap; vma; vma = vma->vm_next) { + reclaim_walk.private = vma; + + if (is_vm_hugetlb_page(vma)) + continue; + + if (type == RECLAIM_ANON && vma->vm_file) + continue; + if (type == RECLAIM_FILE && !vma->vm_file) + continue; + + walk_page_range(vma->vm_start, vma->vm_end, + &reclaim_walk); + } + flush_tlb_mm(mm); + up_read(&mm->mmap_sem); + mmput(mm); + } + put_task_struct(task); + + return count; +} + +const struct file_operations proc_reclaim_operations = { + .write = reclaim_write, + .llseek = noop_llseek, +}; +#endif + #ifdef CONFIG_NUMA struct numa_maps { diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 6dacb93..a24e34e 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -10,6 +10,10 @@ #include #include +extern int isolate_lru_page(struct page *page); +extern void putback_lru_page(struct page *page); +extern unsigned long reclaim_pages_from_list(struct list_head *page_list); + /* * The anon_vma heads a list of private "related" vmas, to scan if * an anonymous page pointing to this anon_vma needs to be unmapped: diff --git a/mm/Kconfig b/mm/Kconfig index ef93df1..314bf49 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -479,3 +479,16 @@ config MEM_SOFT_DIRTY it can be cleared by hands. See Documentation/vm/soft-dirty.txt for more details. + +config PROCESS_RECLAIM + bool "Enable process reclaim" + depends on PROC_FS + default n + help + It allows to reclaim pages of the process by /proc/pid/reclaim. + + (echo file > /proc/PID/reclaim) reclaims file-backed pages only. + (echo anon > /proc/PID/reclaim) reclaims anonymous pages only. + (echo all > /proc/PID/reclaim) reclaims all pages. + + Any other vaule is ignored. diff --git a/mm/internal.h b/mm/internal.h index 8562de0..589a29b 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -86,12 +86,6 @@ static inline void get_page_foll(struct page *page) extern unsigned long highest_memmap_pfn; /* - * in mm/vmscan.c: - */ -extern int isolate_lru_page(struct page *page); -extern void putback_lru_page(struct page *page); - -/* * in mm/rmap.c: */ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); @@ -360,6 +354,7 @@ extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, extern void set_pageblock_order(void); unsigned long reclaim_clean_pages_from_list(struct zone *zone, struct list_head *page_list); + /* The ALLOC_WMARK bits are used as an index to zone->watermark */ #define ALLOC_WMARK_MIN WMARK_MIN #define ALLOC_WMARK_LOW WMARK_LOW diff --git a/mm/vmscan.c b/mm/vmscan.c index 5e12c60..6934f5b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -992,6 +992,65 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, return ret; } +#ifdef CONFIG_PROCESS_RECLAIM +static unsigned long shrink_page(struct page *page, + struct zone *zone, + struct scan_control *sc, + enum ttu_flags ttu_flags, + unsigned long *ret_nr_dirty, + unsigned long *ret_nr_writeback, + bool force_reclaim, + struct list_head *ret_pages) +{ + int reclaimed; + LIST_HEAD(page_list); + list_add(&page->lru, &page_list); + + reclaimed = shrink_page_list(&page_list, zone, sc, ttu_flags, + ret_nr_dirty, ret_nr_writeback, + force_reclaim); + if (!reclaimed) + list_splice(&page_list, ret_pages); + + return reclaimed; +} + +unsigned long reclaim_pages_from_list(struct list_head *page_list) +{ + struct scan_control sc = { + .gfp_mask = GFP_KERNEL, + .priority = DEF_PRIORITY, + .may_unmap = 1, + .may_swap = 1, + }; + + LIST_HEAD(ret_pages); + struct page *page; + unsigned long dummy1, dummy2; + unsigned long nr_reclaimed = 0; + + while (!list_empty(page_list)) { + page = lru_to_page(page_list); + list_del(&page->lru); + + ClearPageActive(page); + nr_reclaimed += shrink_page(page, page_zone(page), &sc, + TTU_UNMAP|TTU_IGNORE_ACCESS, + &dummy1, &dummy2, true, &ret_pages); + } + + while (!list_empty(&ret_pages)) { + page = lru_to_page(&ret_pages); + list_del(&page->lru); + dec_zone_page_state(page, NR_ISOLATED_ANON + + page_is_file_cache(page)); + putback_lru_page(page); + } + + return nr_reclaimed; +} +#endif + /* * Attempt to remove the specified page from its LRU. 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