9276b1bc96
Optimize the critical zonelist scanning for free pages in the kernel memory
allocator by caching the zones that were found to be full recently, and
skipping them.
Remembers the zones in a zonelist that were short of free memory in the
last second. And it stashes a zone-to-node table in the zonelist struct,
to optimize that conversion (minimize its cache footprint.)
Recent changes:
This differs in a significant way from a similar patch that I
posted a week ago. Now, instead of having a nodemask_t of
recently full nodes, I have a bitmask of recently full zones.
This solves a problem that last weeks patch had, which on
systems with multiple zones per node (such as DMA zone) would
take seeing any of these zones full as meaning that all zones
on that node were full.
Also I changed names - from "zonelist faster" to "zonelist cache",
as that seemed to better convey what we're doing here - caching
some of the key zonelist state (for faster access.)
See below for some performance benchmark results. After all that
discussion with David on why I didn't need them, I went and got
some ;). I wanted to verify that I had not hurt the normal case
of memory allocation noticeably. At least for my one little
microbenchmark, I found (1) the normal case wasn't affected, and
(2) workloads that forced scanning across multiple nodes for
memory improved up to 10% fewer System CPU cycles and lower
elapsed clock time ('sys' and 'real'). Good. See details, below.
I didn't have the logic in get_page_from_freelist() for various
full nodes and zone reclaim failures correct. That should be
fixed up now - notice the new goto labels zonelist_scan,
this_zone_full, and try_next_zone, in get_page_from_freelist().
There are two reasons I persued this alternative, over some earlier
proposals that would have focused on optimizing the fake numa
emulation case by caching the last useful zone:
1) Contrary to what I said before, we (SGI, on large ia64 sn2 systems)
have seen real customer loads where the cost to scan the zonelist
was a problem, due to many nodes being full of memory before
we got to a node we could use. Or at least, I think we have.
This was related to me by another engineer, based on experiences
from some time past. So this is not guaranteed. Most likely, though.
The following approach should help such real numa systems just as
much as it helps fake numa systems, or any combination thereof.
2) The effort to distinguish fake from real numa, using node_distance,
so that we could cache a fake numa node and optimize choosing
it over equivalent distance fake nodes, while continuing to
properly scan all real nodes in distance order, was going to
require a nasty blob of zonelist and node distance munging.
The following approach has no new dependency on node distances or
zone sorting.
See comment in the patch below for a description of what it actually does.
Technical details of note (or controversy):
- See the use of "zlc_active" and "did_zlc_setup" below, to delay
adding any work for this new mechanism until we've looked at the
first zone in zonelist. I figured the odds of the first zone
having the memory we needed were high enough that we should just
look there, first, then get fancy only if we need to keep looking.
- Some odd hackery was needed to add items to struct zonelist, while
not tripping up the custom zonelists built by the mm/mempolicy.c
code for MPOL_BIND. My usual wordy comments below explain this.
Search for "MPOL_BIND".
- Some per-node data in the struct zonelist is now modified frequently,
with no locking. Multiple CPU cores on a node could hit and mangle
this data. The theory is that this is just performance hint data,
and the memory allocator will work just fine despite any such mangling.
The fields at risk are the struct 'zonelist_cache' fields 'fullzones'
(a bitmask) and 'last_full_zap' (unsigned long jiffies). It should
all be self correcting after at most a one second delay.
- This still does a linear scan of the same lengths as before. All
I've optimized is making the scan faster, not algorithmically
shorter. It is now able to scan a compact array of 'unsigned
short' in the case of many full nodes, so one cache line should
cover quite a few nodes, rather than each node hitting another
one or two new and distinct cache lines.
- If both Andi and Nick don't find this too complicated, I will be
(pleasantly) flabbergasted.
- I removed the comment claiming we only use one cachline's worth of
zonelist. We seem, at least in the fake numa case, to have put the
lie to that claim.
- I pay no attention to the various watermarks and such in this performance
hint. A node could be marked full for one watermark, and then skipped
over when searching for a page using a different watermark. I think
that's actually quite ok, as it will tend to slightly increase the
spreading of memory over other nodes, away from a memory stressed node.
===============
Performance - some benchmark results and analysis:
This benchmark runs a memory hog program that uses multiple
threads to touch alot of memory as quickly as it can.
Multiple runs were made, touching 12, 38, 64 or 90 GBytes out of
the total 96 GBytes on the system, and using 1, 19, 37, or 55
threads (on a 56 CPU system.) System, user and real (elapsed)
timings were recorded for each run, shown in units of seconds,
in the table below.
Two kernels were tested - 2.6.18-mm3 and the same kernel with
this zonelist caching patch added. The table also shows the
percentage improvement the zonelist caching sys time is over
(lower than) the stock *-mm kernel.
number 2.6.18-mm3 zonelist-cache delta (< 0 good) percent
GBs N ------------ -------------- ---------------- systime
mem threads sys user real sys user real sys user real better
12 1 153 24 177 151 24 176 -2 0 -1 1%
12 19 99 22 8 99 22 8 0 0 0 0%
12 37 111 25 6 112 25 6 1 0 0 -0%
12 55 115 25 5 110 23 5 -5 -2 0 4%
38 1 502 74 576 497 73 570 -5 -1 -6 0%
38 19 426 78 48 373 76 39 -53 -2 -9 12%
38 37 544 83 36 547 82 36 3 -1 0 -0%
38 55 501 77 23 511 80 24 10 3 1 -1%
64 1 917 125 1042 890 124 1014 -27 -1 -28 2%
64 19 1118 138 119 965 141 103 -153 3 -16 13%
64 37 1202 151 94 1136 150 81 -66 -1 -13 5%
64 55 1118 141 61 1072 140 58 -46 -1 -3 4%
90 1 1342 177 1519 1275 174 1450 -67 -3 -69 4%
90 19 2392 199 192 2116 189 176 -276 -10 -16 11%
90 37 3313 238 175 2972 225 145 -341 -13 -30 10%
90 55 1948 210 104 1843 213 100 -105 3 -4 5%
Notes:
1) This test ran a memory hog program that started a specified number N of
threads, and had each thread allocate and touch 1/N'th of
the total memory to be used in the test run in a single loop,
writing a constant word to memory, one store every 4096 bytes.
Watching this test during some earlier trial runs, I would see
each of these threads sit down on one CPU and stay there, for
the remainder of the pass, a different CPU for each thread.
2) The 'real' column is not comparable to the 'sys' or 'user' columns.
The 'real' column is seconds wall clock time elapsed, from beginning
to end of that test pass. The 'sys' and 'user' columns are total
CPU seconds spent on that test pass. For a 19 thread test run,
for example, the sum of 'sys' and 'user' could be up to 19 times the
number of 'real' elapsed wall clock seconds.
3) Tests were run on a fresh, single-user boot, to minimize the amount
of memory already in use at the start of the test, and to minimize
the amount of background activity that might interfere.
4) Tests were done on a 56 CPU, 28 Node system with 96 GBytes of RAM.
5) Notice that the 'real' time gets large for the single thread runs, even
though the measured 'sys' and 'user' times are modest. I'm not sure what
that means - probably something to do with it being slow for one thread to
be accessing memory along ways away. Perhaps the fake numa system, running
ostensibly the same workload, would not show this substantial degradation
of 'real' time for one thread on many nodes -- lets hope not.
6) The high thread count passes (one thread per CPU - on 55 of 56 CPUs)
ran quite efficiently, as one might expect. Each pair of threads needed
to allocate and touch the memory on the node the two threads shared, a
pleasantly parallizable workload.
7) The intermediate thread count passes, when asking for alot of memory forcing
them to go to a few neighboring nodes, improved the most with this zonelist
caching patch.
Conclusions:
* This zonelist cache patch probably makes little difference one way or the
other for most workloads on real numa hardware, if those workloads avoid
heavy off node allocations.
* For memory intensive workloads requiring substantial off-node allocations
on real numa hardware, this patch improves both kernel and elapsed timings
up to ten per-cent.
* For fake numa systems, I'm optimistic, but will have to leave that up to
Rohit Seth to actually test (once I get him a 2.6.18 backport.)
Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: David Rientjes <rientjes@cs.washington.edu>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
764 lines
23 KiB
C
764 lines
23 KiB
C
#ifndef _LINUX_MMZONE_H
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#define _LINUX_MMZONE_H
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#ifdef __KERNEL__
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#ifndef __ASSEMBLY__
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#include <linux/spinlock.h>
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#include <linux/list.h>
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#include <linux/wait.h>
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#include <linux/cache.h>
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#include <linux/threads.h>
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#include <linux/numa.h>
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#include <linux/init.h>
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#include <linux/seqlock.h>
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#include <linux/nodemask.h>
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#include <asm/atomic.h>
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#include <asm/page.h>
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/* Free memory management - zoned buddy allocator. */
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#ifndef CONFIG_FORCE_MAX_ZONEORDER
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#define MAX_ORDER 11
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#else
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#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
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#endif
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#define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
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struct free_area {
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struct list_head free_list;
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unsigned long nr_free;
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};
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struct pglist_data;
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/*
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* zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
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* So add a wild amount of padding here to ensure that they fall into separate
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* cachelines. There are very few zone structures in the machine, so space
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* consumption is not a concern here.
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*/
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#if defined(CONFIG_SMP)
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struct zone_padding {
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char x[0];
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} ____cacheline_internodealigned_in_smp;
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#define ZONE_PADDING(name) struct zone_padding name;
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#else
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#define ZONE_PADDING(name)
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#endif
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enum zone_stat_item {
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NR_ANON_PAGES, /* Mapped anonymous pages */
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NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
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only modified from process context */
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NR_FILE_PAGES,
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NR_SLAB_RECLAIMABLE,
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NR_SLAB_UNRECLAIMABLE,
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NR_PAGETABLE, /* used for pagetables */
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NR_FILE_DIRTY,
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NR_WRITEBACK,
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NR_UNSTABLE_NFS, /* NFS unstable pages */
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NR_BOUNCE,
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NR_VMSCAN_WRITE,
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#ifdef CONFIG_NUMA
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NUMA_HIT, /* allocated in intended node */
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NUMA_MISS, /* allocated in non intended node */
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NUMA_FOREIGN, /* was intended here, hit elsewhere */
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NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
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NUMA_LOCAL, /* allocation from local node */
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NUMA_OTHER, /* allocation from other node */
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#endif
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NR_VM_ZONE_STAT_ITEMS };
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struct per_cpu_pages {
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int count; /* number of pages in the list */
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int high; /* high watermark, emptying needed */
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int batch; /* chunk size for buddy add/remove */
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struct list_head list; /* the list of pages */
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};
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struct per_cpu_pageset {
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struct per_cpu_pages pcp[2]; /* 0: hot. 1: cold */
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#ifdef CONFIG_SMP
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s8 stat_threshold;
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s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
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#endif
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} ____cacheline_aligned_in_smp;
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#ifdef CONFIG_NUMA
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#define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
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#else
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#define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
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#endif
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enum zone_type {
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/*
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* ZONE_DMA is used when there are devices that are not able
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* to do DMA to all of addressable memory (ZONE_NORMAL). Then we
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* carve out the portion of memory that is needed for these devices.
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* The range is arch specific.
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*
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* Some examples
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*
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* Architecture Limit
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* ---------------------------
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* parisc, ia64, sparc <4G
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* s390 <2G
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* arm26 <48M
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* arm Various
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* alpha Unlimited or 0-16MB.
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*
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* i386, x86_64 and multiple other arches
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* <16M.
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*/
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ZONE_DMA,
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#ifdef CONFIG_ZONE_DMA32
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/*
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* x86_64 needs two ZONE_DMAs because it supports devices that are
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* only able to do DMA to the lower 16M but also 32 bit devices that
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* can only do DMA areas below 4G.
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*/
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ZONE_DMA32,
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#endif
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/*
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* Normal addressable memory is in ZONE_NORMAL. DMA operations can be
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* performed on pages in ZONE_NORMAL if the DMA devices support
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* transfers to all addressable memory.
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*/
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ZONE_NORMAL,
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#ifdef CONFIG_HIGHMEM
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/*
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* A memory area that is only addressable by the kernel through
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* mapping portions into its own address space. This is for example
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* used by i386 to allow the kernel to address the memory beyond
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* 900MB. The kernel will set up special mappings (page
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* table entries on i386) for each page that the kernel needs to
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* access.
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*/
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ZONE_HIGHMEM,
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#endif
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MAX_NR_ZONES
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};
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/*
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* When a memory allocation must conform to specific limitations (such
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* as being suitable for DMA) the caller will pass in hints to the
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* allocator in the gfp_mask, in the zone modifier bits. These bits
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* are used to select a priority ordered list of memory zones which
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* match the requested limits. See gfp_zone() in include/linux/gfp.h
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*/
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#if !defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_HIGHMEM)
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#define ZONES_SHIFT 1
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#else
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#define ZONES_SHIFT 2
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#endif
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struct zone {
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/* Fields commonly accessed by the page allocator */
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unsigned long free_pages;
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unsigned long pages_min, pages_low, pages_high;
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/*
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* We don't know if the memory that we're going to allocate will be freeable
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* or/and it will be released eventually, so to avoid totally wasting several
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* GB of ram we must reserve some of the lower zone memory (otherwise we risk
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* to run OOM on the lower zones despite there's tons of freeable ram
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* on the higher zones). This array is recalculated at runtime if the
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* sysctl_lowmem_reserve_ratio sysctl changes.
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*/
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unsigned long lowmem_reserve[MAX_NR_ZONES];
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#ifdef CONFIG_NUMA
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int node;
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/*
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* zone reclaim becomes active if more unmapped pages exist.
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*/
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unsigned long min_unmapped_pages;
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unsigned long min_slab_pages;
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struct per_cpu_pageset *pageset[NR_CPUS];
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#else
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struct per_cpu_pageset pageset[NR_CPUS];
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#endif
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/*
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* free areas of different sizes
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*/
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spinlock_t lock;
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#ifdef CONFIG_MEMORY_HOTPLUG
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/* see spanned/present_pages for more description */
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seqlock_t span_seqlock;
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#endif
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struct free_area free_area[MAX_ORDER];
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ZONE_PADDING(_pad1_)
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/* Fields commonly accessed by the page reclaim scanner */
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spinlock_t lru_lock;
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struct list_head active_list;
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struct list_head inactive_list;
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unsigned long nr_scan_active;
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unsigned long nr_scan_inactive;
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unsigned long nr_active;
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unsigned long nr_inactive;
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unsigned long pages_scanned; /* since last reclaim */
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int all_unreclaimable; /* All pages pinned */
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/* A count of how many reclaimers are scanning this zone */
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atomic_t reclaim_in_progress;
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/* Zone statistics */
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atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
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/*
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* prev_priority holds the scanning priority for this zone. It is
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* defined as the scanning priority at which we achieved our reclaim
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* target at the previous try_to_free_pages() or balance_pgdat()
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* invokation.
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*
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* We use prev_priority as a measure of how much stress page reclaim is
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* under - it drives the swappiness decision: whether to unmap mapped
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* pages.
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*
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* Access to both this field is quite racy even on uniprocessor. But
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* it is expected to average out OK.
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*/
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int prev_priority;
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ZONE_PADDING(_pad2_)
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/* Rarely used or read-mostly fields */
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/*
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* wait_table -- the array holding the hash table
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* wait_table_hash_nr_entries -- the size of the hash table array
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* wait_table_bits -- wait_table_size == (1 << wait_table_bits)
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*
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* The purpose of all these is to keep track of the people
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* waiting for a page to become available and make them
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* runnable again when possible. The trouble is that this
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* consumes a lot of space, especially when so few things
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* wait on pages at a given time. So instead of using
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* per-page waitqueues, we use a waitqueue hash table.
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*
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* The bucket discipline is to sleep on the same queue when
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* colliding and wake all in that wait queue when removing.
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* When something wakes, it must check to be sure its page is
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* truly available, a la thundering herd. The cost of a
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* collision is great, but given the expected load of the
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* table, they should be so rare as to be outweighed by the
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* benefits from the saved space.
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*
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* __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
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* primary users of these fields, and in mm/page_alloc.c
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* free_area_init_core() performs the initialization of them.
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*/
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wait_queue_head_t * wait_table;
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unsigned long wait_table_hash_nr_entries;
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unsigned long wait_table_bits;
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/*
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* Discontig memory support fields.
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*/
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struct pglist_data *zone_pgdat;
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/* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
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unsigned long zone_start_pfn;
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/*
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* zone_start_pfn, spanned_pages and present_pages are all
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* protected by span_seqlock. It is a seqlock because it has
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* to be read outside of zone->lock, and it is done in the main
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* allocator path. But, it is written quite infrequently.
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*
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* The lock is declared along with zone->lock because it is
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* frequently read in proximity to zone->lock. It's good to
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* give them a chance of being in the same cacheline.
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*/
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unsigned long spanned_pages; /* total size, including holes */
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unsigned long present_pages; /* amount of memory (excluding holes) */
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/*
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* rarely used fields:
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*/
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char *name;
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} ____cacheline_internodealigned_in_smp;
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/*
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* The "priority" of VM scanning is how much of the queues we will scan in one
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* go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
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* queues ("queue_length >> 12") during an aging round.
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*/
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#define DEF_PRIORITY 12
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/* Maximum number of zones on a zonelist */
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#define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
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#ifdef CONFIG_NUMA
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/*
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* We cache key information from each zonelist for smaller cache
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* footprint when scanning for free pages in get_page_from_freelist().
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*
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* 1) The BITMAP fullzones tracks which zones in a zonelist have come
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* up short of free memory since the last time (last_fullzone_zap)
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* we zero'd fullzones.
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* 2) The array z_to_n[] maps each zone in the zonelist to its node
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* id, so that we can efficiently evaluate whether that node is
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* set in the current tasks mems_allowed.
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*
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* Both fullzones and z_to_n[] are one-to-one with the zonelist,
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* indexed by a zones offset in the zonelist zones[] array.
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*
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* The get_page_from_freelist() routine does two scans. During the
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* first scan, we skip zones whose corresponding bit in 'fullzones'
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* is set or whose corresponding node in current->mems_allowed (which
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* comes from cpusets) is not set. During the second scan, we bypass
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* this zonelist_cache, to ensure we look methodically at each zone.
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*
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* Once per second, we zero out (zap) fullzones, forcing us to
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* reconsider nodes that might have regained more free memory.
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* The field last_full_zap is the time we last zapped fullzones.
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*
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* This mechanism reduces the amount of time we waste repeatedly
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* reexaming zones for free memory when they just came up low on
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* memory momentarilly ago.
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*
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* The zonelist_cache struct members logically belong in struct
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* zonelist. However, the mempolicy zonelists constructed for
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* MPOL_BIND are intentionally variable length (and usually much
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* shorter). A general purpose mechanism for handling structs with
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* multiple variable length members is more mechanism than we want
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* here. We resort to some special case hackery instead.
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*
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* The MPOL_BIND zonelists don't need this zonelist_cache (in good
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* part because they are shorter), so we put the fixed length stuff
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* at the front of the zonelist struct, ending in a variable length
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* zones[], as is needed by MPOL_BIND.
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|
*
|
|
* Then we put the optional zonelist cache on the end of the zonelist
|
|
* struct. This optional stuff is found by a 'zlcache_ptr' pointer in
|
|
* the fixed length portion at the front of the struct. This pointer
|
|
* both enables us to find the zonelist cache, and in the case of
|
|
* MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
|
|
* to know that the zonelist cache is not there.
|
|
*
|
|
* The end result is that struct zonelists come in two flavors:
|
|
* 1) The full, fixed length version, shown below, and
|
|
* 2) The custom zonelists for MPOL_BIND.
|
|
* The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
|
|
*
|
|
* Even though there may be multiple CPU cores on a node modifying
|
|
* fullzones or last_full_zap in the same zonelist_cache at the same
|
|
* time, we don't lock it. This is just hint data - if it is wrong now
|
|
* and then, the allocator will still function, perhaps a bit slower.
|
|
*/
|
|
|
|
|
|
struct zonelist_cache {
|
|
DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */
|
|
unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */
|
|
unsigned long last_full_zap; /* when last zap'd (jiffies) */
|
|
};
|
|
#else
|
|
struct zonelist_cache;
|
|
#endif
|
|
|
|
/*
|
|
* One allocation request operates on a zonelist. A zonelist
|
|
* is a list of zones, the first one is the 'goal' of the
|
|
* allocation, the other zones are fallback zones, in decreasing
|
|
* priority.
|
|
*
|
|
* If zlcache_ptr is not NULL, then it is just the address of zlcache,
|
|
* as explained above. If zlcache_ptr is NULL, there is no zlcache.
|
|
*/
|
|
|
|
struct zonelist {
|
|
struct zonelist_cache *zlcache_ptr; // NULL or &zlcache
|
|
struct zone *zones[MAX_ZONES_PER_ZONELIST + 1]; // NULL delimited
|
|
#ifdef CONFIG_NUMA
|
|
struct zonelist_cache zlcache; // optional ...
|
|
#endif
|
|
};
|
|
|
|
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
|
|
struct node_active_region {
|
|
unsigned long start_pfn;
|
|
unsigned long end_pfn;
|
|
int nid;
|
|
};
|
|
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
|
|
|
|
#ifndef CONFIG_DISCONTIGMEM
|
|
/* The array of struct pages - for discontigmem use pgdat->lmem_map */
|
|
extern struct page *mem_map;
|
|
#endif
|
|
|
|
/*
|
|
* The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
|
|
* (mostly NUMA machines?) to denote a higher-level memory zone than the
|
|
* zone denotes.
|
|
*
|
|
* On NUMA machines, each NUMA node would have a pg_data_t to describe
|
|
* it's memory layout.
|
|
*
|
|
* Memory statistics and page replacement data structures are maintained on a
|
|
* per-zone basis.
|
|
*/
|
|
struct bootmem_data;
|
|
typedef struct pglist_data {
|
|
struct zone node_zones[MAX_NR_ZONES];
|
|
struct zonelist node_zonelists[MAX_NR_ZONES];
|
|
int nr_zones;
|
|
#ifdef CONFIG_FLAT_NODE_MEM_MAP
|
|
struct page *node_mem_map;
|
|
#endif
|
|
struct bootmem_data *bdata;
|
|
#ifdef CONFIG_MEMORY_HOTPLUG
|
|
/*
|
|
* Must be held any time you expect node_start_pfn, node_present_pages
|
|
* or node_spanned_pages stay constant. Holding this will also
|
|
* guarantee that any pfn_valid() stays that way.
|
|
*
|
|
* Nests above zone->lock and zone->size_seqlock.
|
|
*/
|
|
spinlock_t node_size_lock;
|
|
#endif
|
|
unsigned long node_start_pfn;
|
|
unsigned long node_present_pages; /* total number of physical pages */
|
|
unsigned long node_spanned_pages; /* total size of physical page
|
|
range, including holes */
|
|
int node_id;
|
|
wait_queue_head_t kswapd_wait;
|
|
struct task_struct *kswapd;
|
|
int kswapd_max_order;
|
|
} pg_data_t;
|
|
|
|
#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
|
|
#define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
|
|
#ifdef CONFIG_FLAT_NODE_MEM_MAP
|
|
#define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
|
|
#else
|
|
#define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
|
|
#endif
|
|
#define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
|
|
|
|
#include <linux/memory_hotplug.h>
|
|
|
|
void __get_zone_counts(unsigned long *active, unsigned long *inactive,
|
|
unsigned long *free, struct pglist_data *pgdat);
|
|
void get_zone_counts(unsigned long *active, unsigned long *inactive,
|
|
unsigned long *free);
|
|
void build_all_zonelists(void);
|
|
void wakeup_kswapd(struct zone *zone, int order);
|
|
int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
|
|
int classzone_idx, int alloc_flags);
|
|
|
|
extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
|
|
unsigned long size);
|
|
|
|
#ifdef CONFIG_HAVE_MEMORY_PRESENT
|
|
void memory_present(int nid, unsigned long start, unsigned long end);
|
|
#else
|
|
static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
|
|
#endif
|
|
|
|
#ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
|
|
unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
|
|
#endif
|
|
|
|
/*
|
|
* zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
|
|
*/
|
|
#define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
|
|
|
|
static inline int populated_zone(struct zone *zone)
|
|
{
|
|
return (!!zone->present_pages);
|
|
}
|
|
|
|
static inline int is_highmem_idx(enum zone_type idx)
|
|
{
|
|
#ifdef CONFIG_HIGHMEM
|
|
return (idx == ZONE_HIGHMEM);
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
static inline int is_normal_idx(enum zone_type idx)
|
|
{
|
|
return (idx == ZONE_NORMAL);
|
|
}
|
|
|
|
/**
|
|
* is_highmem - helper function to quickly check if a struct zone is a
|
|
* highmem zone or not. This is an attempt to keep references
|
|
* to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
|
|
* @zone - pointer to struct zone variable
|
|
*/
|
|
static inline int is_highmem(struct zone *zone)
|
|
{
|
|
#ifdef CONFIG_HIGHMEM
|
|
return zone == zone->zone_pgdat->node_zones + ZONE_HIGHMEM;
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
static inline int is_normal(struct zone *zone)
|
|
{
|
|
return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
|
|
}
|
|
|
|
static inline int is_dma32(struct zone *zone)
|
|
{
|
|
#ifdef CONFIG_ZONE_DMA32
|
|
return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
static inline int is_dma(struct zone *zone)
|
|
{
|
|
return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
|
|
}
|
|
|
|
/* These two functions are used to setup the per zone pages min values */
|
|
struct ctl_table;
|
|
struct file;
|
|
int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *,
|
|
void __user *, size_t *, loff_t *);
|
|
extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
|
|
int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
|
|
void __user *, size_t *, loff_t *);
|
|
int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *,
|
|
void __user *, size_t *, loff_t *);
|
|
int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
|
|
struct file *, void __user *, size_t *, loff_t *);
|
|
int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
|
|
struct file *, void __user *, size_t *, loff_t *);
|
|
|
|
#include <linux/topology.h>
|
|
/* Returns the number of the current Node. */
|
|
#ifndef numa_node_id
|
|
#define numa_node_id() (cpu_to_node(raw_smp_processor_id()))
|
|
#endif
|
|
|
|
#ifndef CONFIG_NEED_MULTIPLE_NODES
|
|
|
|
extern struct pglist_data contig_page_data;
|
|
#define NODE_DATA(nid) (&contig_page_data)
|
|
#define NODE_MEM_MAP(nid) mem_map
|
|
#define MAX_NODES_SHIFT 1
|
|
|
|
#else /* CONFIG_NEED_MULTIPLE_NODES */
|
|
|
|
#include <asm/mmzone.h>
|
|
|
|
#endif /* !CONFIG_NEED_MULTIPLE_NODES */
|
|
|
|
extern struct pglist_data *first_online_pgdat(void);
|
|
extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
|
|
extern struct zone *next_zone(struct zone *zone);
|
|
|
|
/**
|
|
* for_each_pgdat - helper macro to iterate over all nodes
|
|
* @pgdat - pointer to a pg_data_t variable
|
|
*/
|
|
#define for_each_online_pgdat(pgdat) \
|
|
for (pgdat = first_online_pgdat(); \
|
|
pgdat; \
|
|
pgdat = next_online_pgdat(pgdat))
|
|
/**
|
|
* for_each_zone - helper macro to iterate over all memory zones
|
|
* @zone - pointer to struct zone variable
|
|
*
|
|
* The user only needs to declare the zone variable, for_each_zone
|
|
* fills it in.
|
|
*/
|
|
#define for_each_zone(zone) \
|
|
for (zone = (first_online_pgdat())->node_zones; \
|
|
zone; \
|
|
zone = next_zone(zone))
|
|
|
|
#ifdef CONFIG_SPARSEMEM
|
|
#include <asm/sparsemem.h>
|
|
#endif
|
|
|
|
#if BITS_PER_LONG == 32
|
|
/*
|
|
* with 32 bit page->flags field, we reserve 9 bits for node/zone info.
|
|
* there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes.
|
|
*/
|
|
#define FLAGS_RESERVED 9
|
|
|
|
#elif BITS_PER_LONG == 64
|
|
/*
|
|
* with 64 bit flags field, there's plenty of room.
|
|
*/
|
|
#define FLAGS_RESERVED 32
|
|
|
|
#else
|
|
|
|
#error BITS_PER_LONG not defined
|
|
|
|
#endif
|
|
|
|
#if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
|
|
!defined(CONFIG_ARCH_POPULATES_NODE_MAP)
|
|
#define early_pfn_to_nid(nid) (0UL)
|
|
#endif
|
|
|
|
#ifdef CONFIG_FLATMEM
|
|
#define pfn_to_nid(pfn) (0)
|
|
#endif
|
|
|
|
#define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
|
|
#define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
|
|
|
|
#ifdef CONFIG_SPARSEMEM
|
|
|
|
/*
|
|
* SECTION_SHIFT #bits space required to store a section #
|
|
*
|
|
* PA_SECTION_SHIFT physical address to/from section number
|
|
* PFN_SECTION_SHIFT pfn to/from section number
|
|
*/
|
|
#define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
|
|
|
|
#define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
|
|
#define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
|
|
|
|
#define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
|
|
|
|
#define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
|
|
#define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
|
|
|
|
#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
|
|
#error Allocator MAX_ORDER exceeds SECTION_SIZE
|
|
#endif
|
|
|
|
struct page;
|
|
struct mem_section {
|
|
/*
|
|
* This is, logically, a pointer to an array of struct
|
|
* pages. However, it is stored with some other magic.
|
|
* (see sparse.c::sparse_init_one_section())
|
|
*
|
|
* Additionally during early boot we encode node id of
|
|
* the location of the section here to guide allocation.
|
|
* (see sparse.c::memory_present())
|
|
*
|
|
* Making it a UL at least makes someone do a cast
|
|
* before using it wrong.
|
|
*/
|
|
unsigned long section_mem_map;
|
|
};
|
|
|
|
#ifdef CONFIG_SPARSEMEM_EXTREME
|
|
#define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
|
|
#else
|
|
#define SECTIONS_PER_ROOT 1
|
|
#endif
|
|
|
|
#define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
|
|
#define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
|
|
#define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
|
|
|
|
#ifdef CONFIG_SPARSEMEM_EXTREME
|
|
extern struct mem_section *mem_section[NR_SECTION_ROOTS];
|
|
#else
|
|
extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
|
|
#endif
|
|
|
|
static inline struct mem_section *__nr_to_section(unsigned long nr)
|
|
{
|
|
if (!mem_section[SECTION_NR_TO_ROOT(nr)])
|
|
return NULL;
|
|
return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
|
|
}
|
|
extern int __section_nr(struct mem_section* ms);
|
|
|
|
/*
|
|
* We use the lower bits of the mem_map pointer to store
|
|
* a little bit of information. There should be at least
|
|
* 3 bits here due to 32-bit alignment.
|
|
*/
|
|
#define SECTION_MARKED_PRESENT (1UL<<0)
|
|
#define SECTION_HAS_MEM_MAP (1UL<<1)
|
|
#define SECTION_MAP_LAST_BIT (1UL<<2)
|
|
#define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
|
|
#define SECTION_NID_SHIFT 2
|
|
|
|
static inline struct page *__section_mem_map_addr(struct mem_section *section)
|
|
{
|
|
unsigned long map = section->section_mem_map;
|
|
map &= SECTION_MAP_MASK;
|
|
return (struct page *)map;
|
|
}
|
|
|
|
static inline int valid_section(struct mem_section *section)
|
|
{
|
|
return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
|
|
}
|
|
|
|
static inline int section_has_mem_map(struct mem_section *section)
|
|
{
|
|
return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
|
|
}
|
|
|
|
static inline int valid_section_nr(unsigned long nr)
|
|
{
|
|
return valid_section(__nr_to_section(nr));
|
|
}
|
|
|
|
static inline struct mem_section *__pfn_to_section(unsigned long pfn)
|
|
{
|
|
return __nr_to_section(pfn_to_section_nr(pfn));
|
|
}
|
|
|
|
static inline int pfn_valid(unsigned long pfn)
|
|
{
|
|
if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
|
|
return 0;
|
|
return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
|
|
}
|
|
|
|
/*
|
|
* These are _only_ used during initialisation, therefore they
|
|
* can use __initdata ... They could have names to indicate
|
|
* this restriction.
|
|
*/
|
|
#ifdef CONFIG_NUMA
|
|
#define pfn_to_nid(pfn) \
|
|
({ \
|
|
unsigned long __pfn_to_nid_pfn = (pfn); \
|
|
page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
|
|
})
|
|
#else
|
|
#define pfn_to_nid(pfn) (0)
|
|
#endif
|
|
|
|
#define early_pfn_valid(pfn) pfn_valid(pfn)
|
|
void sparse_init(void);
|
|
#else
|
|
#define sparse_init() do {} while (0)
|
|
#define sparse_index_init(_sec, _nid) do {} while (0)
|
|
#endif /* CONFIG_SPARSEMEM */
|
|
|
|
#ifdef CONFIG_NODES_SPAN_OTHER_NODES
|
|
#define early_pfn_in_nid(pfn, nid) (early_pfn_to_nid(pfn) == (nid))
|
|
#else
|
|
#define early_pfn_in_nid(pfn, nid) (1)
|
|
#endif
|
|
|
|
#ifndef early_pfn_valid
|
|
#define early_pfn_valid(pfn) (1)
|
|
#endif
|
|
|
|
void memory_present(int nid, unsigned long start, unsigned long end);
|
|
unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _LINUX_MMZONE_H */
|