forked from luck/tmp_suning_uos_patched
a3b2d69269
Try to use CSS ID for records in swap_cgroup. By this, on 64bit machine,
size of swap_cgroup goes down to 2 bytes from 8bytes.
This means, when 2GB of swap is equipped, (assume the page size is 4096bytes)
From size of swap_cgroup = 2G/4k * 8 = 4Mbytes.
To size of swap_cgroup = 2G/4k * 2 = 1Mbytes.
Reduction is large. Of course, there are trade-offs. This CSS ID will
add overhead to swap-in/swap-out/swap-free.
But in general,
- swap is a resource which the user tend to avoid use.
- If swap is never used, swap_cgroup area is not used.
- Reading traditional manuals, size of swap should be proportional to
size of memory. Memory size of machine is increasing now.
I think reducing size of swap_cgroup makes sense.
Note:
- ID->CSS lookup routine has no locks, it's under RCU-Read-Side.
- memcg can be obsolete at rmdir() but not freed while refcnt from
swap_cgroup is available.
Changelog v4->v5:
- reworked on to memcg-charge-swapcache-to-proper-memcg.patch
Changlog ->v4:
- fixed not configured case.
- deleted unnecessary comments.
- fixed NULL pointer bug.
- fixed message in dmesg.
[nishimura@mxp.nes.nec.co.jp: css_tryget can be called twice in !PageCgroupUsed case]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
126 lines
2.9 KiB
C
126 lines
2.9 KiB
C
#ifndef __LINUX_PAGE_CGROUP_H
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#define __LINUX_PAGE_CGROUP_H
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR
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#include <linux/bit_spinlock.h>
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/*
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* Page Cgroup can be considered as an extended mem_map.
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* A page_cgroup page is associated with every page descriptor. The
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* page_cgroup helps us identify information about the cgroup
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* All page cgroups are allocated at boot or memory hotplug event,
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* then the page cgroup for pfn always exists.
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*/
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struct page_cgroup {
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unsigned long flags;
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struct mem_cgroup *mem_cgroup;
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struct page *page;
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struct list_head lru; /* per cgroup LRU list */
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};
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void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat);
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void __init page_cgroup_init(void);
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struct page_cgroup *lookup_page_cgroup(struct page *page);
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enum {
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/* flags for mem_cgroup */
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PCG_LOCK, /* page cgroup is locked */
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PCG_CACHE, /* charged as cache */
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PCG_USED, /* this object is in use. */
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};
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#define TESTPCGFLAG(uname, lname) \
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static inline int PageCgroup##uname(struct page_cgroup *pc) \
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{ return test_bit(PCG_##lname, &pc->flags); }
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#define SETPCGFLAG(uname, lname) \
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static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
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{ set_bit(PCG_##lname, &pc->flags); }
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#define CLEARPCGFLAG(uname, lname) \
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static inline void ClearPageCgroup##uname(struct page_cgroup *pc) \
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{ clear_bit(PCG_##lname, &pc->flags); }
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/* Cache flag is set only once (at allocation) */
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TESTPCGFLAG(Cache, CACHE)
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TESTPCGFLAG(Used, USED)
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CLEARPCGFLAG(Used, USED)
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static inline int page_cgroup_nid(struct page_cgroup *pc)
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{
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return page_to_nid(pc->page);
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}
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static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
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{
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return page_zonenum(pc->page);
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}
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static inline void lock_page_cgroup(struct page_cgroup *pc)
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{
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bit_spin_lock(PCG_LOCK, &pc->flags);
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}
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static inline int trylock_page_cgroup(struct page_cgroup *pc)
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{
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return bit_spin_trylock(PCG_LOCK, &pc->flags);
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}
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static inline void unlock_page_cgroup(struct page_cgroup *pc)
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{
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bit_spin_unlock(PCG_LOCK, &pc->flags);
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}
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#else /* CONFIG_CGROUP_MEM_RES_CTLR */
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struct page_cgroup;
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static inline void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
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{
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}
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static inline struct page_cgroup *lookup_page_cgroup(struct page *page)
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{
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return NULL;
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}
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static inline void page_cgroup_init(void)
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{
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}
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#endif
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
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#include <linux/swap.h>
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extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id);
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extern unsigned short lookup_swap_cgroup(swp_entry_t ent);
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extern int swap_cgroup_swapon(int type, unsigned long max_pages);
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extern void swap_cgroup_swapoff(int type);
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#else
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#include <linux/swap.h>
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static inline
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unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
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{
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return 0;
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}
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static inline
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unsigned short lookup_swap_cgroup(swp_entry_t ent)
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{
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return 0;
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}
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static inline int
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swap_cgroup_swapon(int type, unsigned long max_pages)
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{
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return 0;
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}
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static inline void swap_cgroup_swapoff(int type)
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{
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return;
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}
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#endif
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#endif
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