Attached patch implements VM strict overcommit with the following
changes over the previous patch:
- remove overcommit modes 3 and 4
- make mode 2's rule "swap + a configurable % of phys RAM"
- introduce overcommit_ratio sysctl for setting the above
percent. The default is 50%. You may want it higher or
lower depending on your machine and needs.
- (unrelated to the controversy) back out some of the shmem
changes. I am weary of them and they would be best brought
forward from 2.4-ac in pieces. 2.4-ac, btw, has quite
a few shmem fixes.
These were discussed with Alan and should be acceptable.
Linus, patch is against 2.5.27, please apply.
Robert Love
diff -urN linux-2.5.27/Documentation/sysctl/vm.txt linux/Documentation/sysctl/vm.txt
--- linux-2.5.27/Documentation/sysctl/vm.txt Sat Jul 20 12:11:30 2002
+++ linux/Documentation/sysctl/vm.txt Sat Jul 20 18:59:37 2002
@@ -78,7 +78,21 @@
programs that malloc() huge amounts of memory "just-in-case"
and don't use much of it.
-Look at: mm/mmap.c::vm_enough_memory() for more information.
+A value of 2 introduces a new "strict overcommit" policy
+that attempts to prevent any overcommit of memory.
+
+The default value is 0.
+
+See Documentation/vm/overcommit-accounting and
+mm/mmap.c::vm_enough_memory() for more information.
+
+==============================================================
+
+overcommit_ratio:
+
+When overcommit_memory is set to 2, the committed address
+space is not permitted to exceed swap plus this percentage
+of physical RAM. The default is 50%. See above.
==============================================================
diff -urN linux-2.5.27/Documentation/vm/overcommit-accounting linux/Documentation/vm/overcommit-accounting
--- linux-2.5.27/Documentation/vm/overcommit-accounting Wed Dec 31 16:00:00 1969
+++ linux/Documentation/vm/overcommit-accounting Sat Jul 20 18:40:51 2002
@@ -0,0 +1,70 @@
+The Linux kernel supports four overcommit handling modes
+
+0 - Heuristic overcommit handling. Obvious overcommits of
+ address space are refused. Used for a typical system. It
+ ensures a seriously wild allocation fails while allowing
+ overcommit to reduce swap usage. This is the default.
+
+1 - No overcommit handling. Appropriate for some scientific
+ applications.
+
+2 - (NEW) strict overcommit. The total address space commit
+ for the system is not permitted to exceed swap + a
+ configurable percentage (default is 50) of physical RAM.
+ Depending on the percentage you use, in most situations
+ this means a process will not be killed while accessing
+ pages but will receive errors on memory allocation as
+ appropriate.
+
+The overcommit policy is set via the sysctl `vm.overcommit_memory'.
+
+The overcommit percentage is set via `vm.overcommit_ratio'.
+
+Gotchas
+-------
+
+The C language stack growth does an implicit mremap. If you want absolute
+guarantees and run close to the edge you MUST mmap your stack for the
+largest size you think you will need. For typical stack usage is does
+not matter much but its a corner case if you really really care
+
+In modes 2 and 3 the MAP_NORESERVE flag is ignored.
+
+
+How It Works
+------------
+
+The overcommit is based on the following rules
+
+For a file backed map
+ SHARED or READ only - 0 cost (the file is the map not swap)
+
+ WRITABLE SHARED - size of mapping per instance
+
+For a direct map
+ SHARED or READ only - size of mapping
+ PRIVATE WRITEABLE - size of mapping per instance
+
+Additional accounting
+ Pages made writable copies by mmap
+ shmfs memory drawn from the same pool
+
+Status
+------
+
+o We account mmap memory mappings
+o We account mprotect changes in commit
+o We account mremap changes in size
+o We account brk
+o We account munmap
+o We report the commit status in /proc
+o Account and check on fork
+o Review stack handling/building on exec
+o SHMfs accounting
+o Implement actual limit enforcement
+
+To Do
+-----
+o Account ptrace pages (this is hard)
+o Account for shared anonymous mappings properly
+ - right now we account them per instance
diff -urN linux-2.5.27/fs/exec.c linux/fs/exec.c
--- linux-2.5.27/fs/exec.c Sat Jul 20 12:11:14 2002
+++ linux/fs/exec.c Sat Jul 20 16:19:35 2002
@@ -313,8 +313,13 @@
mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!mpnt)
- return -ENOMEM;
-
+ return -ENOMEM;
+
+ if (!vm_enough_memory((STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))>>PAGE_SHIFT)) {
+ kmem_cache_free(vm_area_cachep, mpnt);
+ return -ENOMEM;
+ }
+
down_write(¤t->mm->mmap_sem);
{
mpnt->vm_mm = current->mm;
diff -urN linux-2.5.27/fs/proc/proc_misc.c linux/fs/proc/proc_misc.c
--- linux-2.5.27/fs/proc/proc_misc.c Sat Jul 20 12:11:08 2002
+++ linux/fs/proc/proc_misc.c Sat Jul 20 16:19:35 2002
@@ -126,11 +126,13 @@
return proc_calc_metrics(page, start, off, count, eof, len);
}
+extern atomic_t vm_committed_space;
+
static int meminfo_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
struct sysinfo i;
- int len;
+ int len, committed;
struct page_state ps;
get_page_state(&ps);
@@ -140,6 +142,7 @@
#define K(x) ((x) << (PAGE_SHIFT - 10))
si_meminfo(&i);
si_swapinfo(&i);
+ committed = atomic_read(&vm_committed_space);
/*
* Tagged format, for easy grepping and expansion.
@@ -160,6 +163,7 @@
"SwapFree: %8lu kB\n"
"Dirty: %8lu kB\n"
"Writeback: %8lu kB\n"
+ "Committed_AS: %8u kB\n"
"PageTables: %8lu kB\n"
"PteChainTot: %8lu kB\n"
"PteChainUsed: %8lu kB\n",
@@ -178,6 +182,7 @@
K(i.freeswap),
K(ps.nr_dirty),
K(ps.nr_writeback),
+ K(committed),
K(ps.nr_page_table_pages),
K(ps.nr_pte_chain_pages),
ps.used_pte_chains_bytes >> 10
diff -urN linux-2.5.27/include/linux/mm.h linux/include/linux/mm.h
--- linux-2.5.27/include/linux/mm.h Sat Jul 20 12:11:06 2002
+++ linux/include/linux/mm.h Sat Jul 20 16:19:35 2002
@@ -103,8 +103,9 @@
#define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */
#define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
#define VM_RESERVED 0x00080000 /* Don't unmap it from swap_out */
+#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
-#define VM_STACK_FLAGS (0x00000100 | VM_DATA_DEFAULT_FLAGS)
+#define VM_STACK_FLAGS (0x00000100 | VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT)
#define VM_READHINTMASK (VM_SEQ_READ | VM_RAND_READ)
#define VM_ClearReadHint(v) (v)->vm_flags &= ~VM_READHINTMASK
@@ -430,7 +431,7 @@
return ret;
}
-extern int do_munmap(struct mm_struct *, unsigned long, size_t);
+extern int do_munmap(struct mm_struct *, unsigned long, size_t, int);
extern unsigned long do_brk(unsigned long, unsigned long);
@@ -472,31 +473,8 @@
void page_cache_readaround(struct file *file, unsigned long offset);
void handle_ra_miss(struct file *file);
-/* vma is the first one with address < vma->vm_end,
- * and even address < vma->vm_start. Have to extend vma. */
-static inline int expand_stack(struct vm_area_struct * vma, unsigned long address)
-{
- unsigned long grow;
-
- /*
- * vma->vm_start/vm_end cannot change under us because the caller is required
- * to hold the mmap_sem in write mode. We need to get the spinlock only
- * before relocating the vma range ourself.
- */
- address &= PAGE_MASK;
- grow = (vma->vm_start - address) >> PAGE_SHIFT;
- if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
- ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) > current->rlim[RLIMIT_AS].rlim_cur)
- return -ENOMEM;
- spin_lock(&vma->vm_mm->page_table_lock);
- vma->vm_start = address;
- vma->vm_pgoff -= grow;
- vma->vm_mm->total_vm += grow;
- if (vma->vm_flags & VM_LOCKED)
- vma->vm_mm->locked_vm += grow;
- spin_unlock(&vma->vm_mm->page_table_lock);
- return 0;
-}
+/* Do stack extension */
+extern int expand_stack(struct vm_area_struct * vma, unsigned long address);
/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
diff -urN linux-2.5.27/include/linux/mman.h linux/include/linux/mman.h
--- linux-2.5.27/include/linux/mman.h Sat Jul 20 12:11:08 2002
+++ linux/include/linux/mman.h Sat Jul 20 16:19:35 2002
@@ -6,4 +6,7 @@
#define MREMAP_MAYMOVE 1
#define MREMAP_FIXED 2
+extern int vm_enough_memory(long pages);
+extern void vm_unacct_memory(long pages);
+
#endif /* _LINUX_MMAN_H */
diff -urN linux-2.5.27/include/linux/sysctl.h linux/include/linux/sysctl.h
--- linux-2.5.27/include/linux/sysctl.h Sat Jul 20 12:11:05 2002
+++ linux/include/linux/sysctl.h Sat Jul 20 18:39:50 2002
@@ -149,6 +149,7 @@
VM_DIRTY_WB_CS=14, /* dirty_writeback_centisecs */
VM_DIRTY_EXPIRE_CS=15, /* dirty_expire_centisecs */
VM_NR_PDFLUSH_THREADS=16, /* nr_pdflush_threads */
+ VM_OVERCOMMIT_RATIO=17, /* percent of RAM to allow overcommit in */
};
diff -urN linux-2.5.27/ipc/shm.c linux/ipc/shm.c
--- linux-2.5.27/ipc/shm.c Sat Jul 20 12:11:20 2002
+++ linux/ipc/shm.c Sat Jul 20 16:19:35 2002
@@ -670,7 +670,7 @@
shmdnext = shmd->vm_next;
if (shmd->vm_ops == &shm_vm_ops
&& shmd->vm_start - (shmd->vm_pgoff << PAGE_SHIFT) == (ulong) shmaddr) {
- do_munmap(mm, shmd->vm_start, shmd->vm_end - shmd->vm_start);
+ do_munmap(mm, shmd->vm_start, shmd->vm_end - shmd->vm_start, 1);
retval = 0;
}
}
diff -urN linux-2.5.27/kernel/fork.c linux/kernel/fork.c
--- linux-2.5.27/kernel/fork.c Sat Jul 20 12:11:07 2002
+++ linux/kernel/fork.c Sat Jul 20 16:19:35 2002
@@ -23,6 +23,7 @@
#include <linux/personality.h>
#include <linux/file.h>
#include <linux/binfmts.h>
+#include <linux/mman.h>
#include <linux/fs.h>
#include <linux/security.h>
@@ -181,6 +182,7 @@
{
struct vm_area_struct * mpnt, *tmp, **pprev;
int retval;
+ unsigned long charge = 0;
flush_cache_mm(current->mm);
mm->locked_vm = 0;
@@ -208,6 +210,17 @@
retval = -ENOMEM;
if(mpnt->vm_flags & VM_DONTCOPY)
continue;
+
+ /*
+ * FIXME: shared writable map accounting should be one off
+ */
+ if (mpnt->vm_flags & VM_ACCOUNT) {
+ unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
+ if (!vm_enough_memory(len))
+ goto fail_nomem;
+ charge += len;
+ }
+
tmp = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!tmp)
goto fail_nomem;
@@ -248,9 +261,12 @@
retval = 0;
build_mmap_rb(mm);
-fail_nomem:
+out:
flush_tlb_mm(current->mm);
return retval;
+fail_nomem:
+ vm_unacct_memory(charge);
+ goto out;
}
spinlock_t mmlist_lock __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
diff -urN linux-2.5.27/kernel/sysctl.c linux/kernel/sysctl.c
--- linux-2.5.27/kernel/sysctl.c Sat Jul 20 12:11:07 2002
+++ linux/kernel/sysctl.c Sat Jul 20 18:40:40 2002
@@ -45,6 +45,7 @@
extern int panic_timeout;
extern int C_A_D;
extern int sysctl_overcommit_memory;
+extern int sysctl_overcommit_ratio;
extern int max_threads;
extern atomic_t nr_queued_signals;
extern int max_queued_signals;
@@ -268,6 +269,9 @@
static ctl_table vm_table[] = {
{VM_OVERCOMMIT_MEMORY, "overcommit_memory", &sysctl_overcommit_memory,
sizeof(sysctl_overcommit_memory), 0644, NULL, &proc_dointvec},
+ {VM_OVERCOMMIT_RATIO, "overcommit_ratio",
+ &sysctl_overcommit_ratio, sizeof(sysctl_overcommit_ratio), 0644,
+ NULL, &proc_dointvec},
{VM_PAGERDAEMON, "kswapd",
&pager_daemon, sizeof(pager_daemon_t), 0644, NULL, &proc_dointvec},
{VM_PAGE_CLUSTER, "page-cluster",
Binary files linux-2.5.27/mm/.mmap.c.swp and linux/mm/.mmap.c.swp differ
diff -urN linux-2.5.27/mm/mmap.c linux/mm/mmap.c
--- linux-2.5.27/mm/mmap.c Sat Jul 20 12:11:07 2002
+++ linux/mm/mmap.c Sat Jul 20 18:38:23 2002
@@ -1,8 +1,11 @@
/*
- * linux/mm/mmap.c
+ * mm/mmap.c
*
* Written by obz.
+ *
+ * Address space accounting code <alan@redhat.com>
*/
+
#include <linux/slab.h>
#include <linux/shm.h>
#include <linux/mman.h>
@@ -48,52 +51,91 @@
__S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
};
-int sysctl_overcommit_memory;
+int sysctl_overcommit_memory = 0; /* default is heuristic overcommit */
+int sysctl_overcommit_ratio = 50; /* default is 50% */
+atomic_t vm_committed_space = ATOMIC_INIT(0);
-/* Check that a process has enough memory to allocate a
- * new virtual mapping.
+/*
+ * Check that a process has enough memory to allocate a new virtual
+ * mapping. 1 means there is enough memory for the allocation to
+ * succeed and 0 implies there is not.
+ *
+ * We currently support three overcommit policies, which are set via the
+ * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-acounting
+ *
+ * Strict overcommit modes added 2002 Feb 26 by Alan Cox.
+ * Additional code 2002 Jul 20 by Robert Love.
*/
int vm_enough_memory(long pages)
{
- /* Stupid algorithm to decide if we have enough memory: while
- * simple, it hopefully works in most obvious cases.. Easy to
- * fool it, but this should catch most mistakes.
- */
- /* 23/11/98 NJC: Somewhat less stupid version of algorithm,
- * which tries to do "TheRightThing". Instead of using half of
- * (buffers+cache), use the minimum values. Allow an extra 2%
- * of num_physpages for safety margin.
- */
+ unsigned long free, allowed;
+ struct sysinfo i;
- unsigned long free;
-
- /* Sometimes we want to use more memory than we have. */
- if (sysctl_overcommit_memory)
- return 1;
-
- /* The page cache contains buffer pages these days.. */
- free = get_page_cache_size();
- free += nr_free_pages();
- free += nr_swap_pages;
+ atomic_add(pages, &vm_committed_space);
- /*
- * This double-counts: the nrpages are both in the page-cache
- * and in the swapper space. At the same time, this compensates
- * for the swap-space over-allocation (ie "nr_swap_pages" being
- * too small.
+ /*
+ * Sometimes we want to use more memory than we have
*/
- free += swapper_space.nrpages;
+ if (sysctl_overcommit_memory == 1)
+ return 1;
+
+ if (sysctl_overcommit_memory == 0) {
+ free = get_page_cache_size();
+ free += nr_free_pages();
+ free += nr_swap_pages;
+
+ /*
+ * This double-counts: the nrpages are both in the
+ * page-cache and in the swapper space. At the same time,
+ * this compensates for the swap-space over-allocation
+ * (ie "nr_swap_pages" being too small).
+ */
+ free += swapper_space.nrpages;
+
+ /*
+ * The code below doesn't account for free space in the
+ * inode and dentry slab cache, slab cache fragmentation,
+ * inodes and dentries which will become freeable under
+ * VM load, etc. Lets just hope all these (complex)
+ * factors balance out...
+ */
+ free += (dentry_stat.nr_unused * sizeof(struct dentry)) >>
+ PAGE_SHIFT;
+ free += (inodes_stat.nr_unused * sizeof(struct inode)) >>
+ PAGE_SHIFT;
+
+ if (free > pages)
+ return 1;
+ atomic_sub(pages, &vm_committed_space);
+ return 0;
+ }
/*
- * The code below doesn't account for free space in the inode
- * and dentry slab cache, slab cache fragmentation, inodes and
- * dentries which will become freeable under VM load, etc.
- * Lets just hope all these (complex) factors balance out...
+ * FIXME: need to add arch hooks to get the bits we need
+ * without this higher overhead crap
*/
- free += (dentry_stat.nr_unused * sizeof(struct dentry)) >> PAGE_SHIFT;
- free += (inodes_stat.nr_unused * sizeof(struct inode)) >> PAGE_SHIFT;
+ si_meminfo(&i);
+ allowed = i.totalram * sysctl_overcommit_ratio / 100;
+ allowed += total_swap_pages;
+
+ if (atomic_read(&vm_committed_space) < allowed)
+ return 1;
+
+ atomic_sub(pages, &vm_committed_space);
+
+ return 0;
+}
- return free > pages;
+void inline vm_unacct_memory(long pages)
+{
+ atomic_sub(pages, &vm_committed_space);
+}
+
+void vm_unacct_vma(struct vm_area_struct *vma)
+{
+ int len = vma->vm_end - vma->vm_start;
+ if (vma->vm_flags & VM_ACCOUNT)
+ vm_unacct_memory(len >> PAGE_SHIFT);
}
/* Remove one vm structure from the inode's i_mapping address space. */
@@ -162,7 +204,7 @@
/* Always allow shrinking brk. */
if (brk <= mm->brk) {
- if (!do_munmap(mm, newbrk, oldbrk-newbrk))
+ if (!do_munmap(mm, newbrk, oldbrk-newbrk, 1))
goto set_brk;
goto out;
}
@@ -176,10 +218,6 @@
if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
goto out;
- /* Check if we have enough memory.. */
- if (!vm_enough_memory((newbrk-oldbrk) >> PAGE_SHIFT))
- goto out;
-
/* Ok, looks good - let it rip. */
if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
goto out;
@@ -385,8 +423,9 @@
return 0;
}
-unsigned long do_mmap_pgoff(struct file * file, unsigned long addr, unsigned long len,
- unsigned long prot, unsigned long flags, unsigned long pgoff)
+unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flags, unsigned long pgoff)
{
struct mm_struct * mm = current->mm;
struct vm_area_struct * vma, * prev;
@@ -394,6 +433,7 @@
int correct_wcount = 0;
int error;
rb_node_t ** rb_link, * rb_parent;
+ unsigned long charged = 0;
if (file && (!file->f_op || !file->f_op->mmap))
return -ENODEV;
@@ -480,7 +520,7 @@
munmap_back:
vma = find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent);
if (vma && vma->vm_start < addr + len) {
- if (do_munmap(mm, addr, len))
+ if (do_munmap(mm, addr, len, 1))
return -ENOMEM;
goto munmap_back;
}
@@ -490,11 +530,17 @@
> current->rlim[RLIMIT_AS].rlim_cur)
return -ENOMEM;
+ if (sysctl_overcommit_memory > 1)
+ vm_flags &= ~MAP_NORESERVE;
+
/* Private writable mapping? Check memory availability.. */
- if ((vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE &&
- !(flags & MAP_NORESERVE) &&
- !vm_enough_memory(len >> PAGE_SHIFT))
- return -ENOMEM;
+ if ((((vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE) ||
+ (file == NULL)) && !(flags & MAP_NORESERVE)) {
+ charged = len >> PAGE_SHIFT;
+ if (!vm_enough_memory(charged))
+ return -ENOMEM;
+ vm_flags |= VM_ACCOUNT;
+ }
/* Can we just expand an old anonymous mapping? */
if (!file && !(vm_flags & VM_SHARED) && rb_parent)
@@ -506,8 +552,9 @@
* not unmapped, but the maps are removed from the list.
*/
vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+ error = -ENOMEM;
if (!vma)
- return -ENOMEM;
+ goto unacct_error;
vma->vm_mm = mm;
vma->vm_start = addr;
@@ -570,6 +617,9 @@
zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start);
free_vma:
kmem_cache_free(vm_area_cachep, vma);
+unacct_error:
+ if (charged)
+ vm_unacct_memory(charged);
return error;
}
@@ -699,6 +749,45 @@
return prev ? prev->vm_next : vma;
}
+/*
+ * vma is the first one with address < vma->vm_end,
+ * and even address < vma->vm_start. Have to extend vma.
+ */
+int expand_stack(struct vm_area_struct * vma, unsigned long address)
+{
+ unsigned long grow;
+
+ /*
+ * vma->vm_start/vm_end cannot change under us because the caller
+ * is required to hold the mmap_sem in write mode. We need to get
+ * the spinlock only before relocating the vma range ourself.
+ */
+ address &= PAGE_MASK;
+ spin_lock(&vma->vm_mm->page_table_lock);
+ grow = (vma->vm_start - address) >> PAGE_SHIFT;
+
+ /* Overcommit.. */
+ if(!vm_enough_memory(grow)) {
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return -ENOMEM;
+ }
+
+ if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
+ ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) >
+ current->rlim[RLIMIT_AS].rlim_cur) {
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ vm_unacct_memory(grow);
+ return -ENOMEM;
+ }
+ vma->vm_start = address;
+ vma->vm_pgoff -= grow;
+ vma->vm_mm->total_vm += grow;
+ if (vma->vm_flags & VM_LOCKED)
+ vma->vm_mm->locked_vm += grow;
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return 0;
+}
+
#ifdef ARCH_STACK_GROWSUP
struct vm_area_struct * find_extend_vma(struct mm_struct * mm, unsigned long addr)
{
@@ -824,7 +913,6 @@
kmem_cache_free(vm_area_cachep, area);
}
-
/*
* Update the VMA and inode share lists.
*
@@ -851,19 +939,25 @@
struct vm_area_struct *mpnt,
struct vm_area_struct *prev,
unsigned long start,
- unsigned long end)
+ unsigned long end,
+ int acct)
{
mmu_gather_t *tlb;
tlb = tlb_gather_mmu(mm, 0);
do {
- unsigned long from, to;
+ unsigned long from, to, len;
from = start < mpnt->vm_start ? mpnt->vm_start : start;
to = end > mpnt->vm_end ? mpnt->vm_end : end;
unmap_page_range(tlb, mpnt, from, to);
+
+ if (acct && (mpnt->vm_flags & VM_ACCOUNT)) {
+ len = to - from;
+ vm_unacct_memory(len >> PAGE_SHIFT);
+ }
} while ((mpnt = mpnt->vm_next) != NULL);
free_pgtables(tlb, prev, start, end);
@@ -941,7 +1035,7 @@
* work. This now handles partial unmappings.
* Jeremy Fitzhardine <jeremy@sw.oz.au>
*/
-int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
+int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, int acct)
{
unsigned long end;
struct vm_area_struct *mpnt, *prev, *last;
@@ -985,7 +1079,7 @@
*/
spin_lock(&mm->page_table_lock);
mpnt = touched_by_munmap(mm, mpnt, prev, end);
- unmap_region(mm, mpnt, prev, start, end);
+ unmap_region(mm, mpnt, prev, start, end, acct);
spin_unlock(&mm->page_table_lock);
/* Fix up all other VM information */
@@ -1000,7 +1094,7 @@
struct mm_struct *mm = current->mm;
down_write(&mm->mmap_sem);
- ret = do_munmap(mm, addr, len);
+ ret = do_munmap(mm, addr, len, 1);
up_write(&mm->mmap_sem);
return ret;
}
@@ -1037,7 +1131,7 @@
munmap_back:
vma = find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent);
if (vma && vma->vm_start < addr + len) {
- if (do_munmap(mm, addr, len))
+ if (do_munmap(mm, addr, len, 1))
return -ENOMEM;
goto munmap_back;
}
@@ -1053,7 +1147,7 @@
if (!vm_enough_memory(len >> PAGE_SHIFT))
return -ENOMEM;
- flags = VM_DATA_DEFAULT_FLAGS | mm->def_flags;
+ flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
/* Can we just expand an old anonymous mapping? */
if (rb_parent && vma_merge(mm, prev, rb_parent, addr, addr + len, flags))
@@ -1063,8 +1157,10 @@
* create a vma struct for an anonymous mapping
*/
vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
- if (!vma)
+ if (!vma) {
+ vm_unacct_memory(len >> PAGE_SHIFT);
return -ENOMEM;
+ }
vma->vm_mm = mm;
vma->vm_start = addr;
@@ -1120,6 +1216,13 @@
unsigned long start = mpnt->vm_start;
unsigned long end = mpnt->vm_end;
+ /*
+ * If the VMA has been charged for, account for its
+ * removal
+ */
+ if (mpnt->vm_flags & VM_ACCOUNT)
+ vm_unacct_vma(mpnt);
+
mm->map_count--;
unmap_page_range(tlb, mpnt, start, end);
mpnt = mpnt->vm_next;
diff -urN linux-2.5.27/mm/mprotect.c linux/mm/mprotect.c
--- linux-2.5.27/mm/mprotect.c Sat Jul 20 12:11:14 2002
+++ linux/mm/mprotect.c Sat Jul 20 16:19:35 2002
@@ -1,7 +1,10 @@
/*
- * linux/mm/mprotect.c
+ * mm/mprotect.c
*
* (C) Copyright 1994 Linus Torvalds
+ *
+ * Address space accounting code <alan@redhat.com>
+ * (C) Copyright 2002 Red Hat Inc, All Rights Reserved
*/
#include <linux/mm.h>
#include <linux/slab.h>
@@ -247,6 +250,7 @@
{
pgprot_t newprot;
int error;
+ unsigned long charged = 0;
if (newflags == vma->vm_flags) {
*pprev = vma;
@@ -263,9 +267,18 @@
else
error = mprotect_fixup_middle(vma, pprev, start, end, newflags, newprot);
- if (error)
+ if (error) {
+ if (newflags & PROT_WRITE)
+ vm_unacct_memory(charged);
return error;
+ }
+ /*
+ * Delayed accounting for reduction of memory use - done last to
+ * avoid allocation races
+ */
+ if (charged && !(newflags & PROT_WRITE))
+ vm_unacct_memory(charged);
change_protection(vma, start, end, newprot);
return 0;
}
diff -urN linux-2.5.27/mm/mremap.c linux/mm/mremap.c
--- linux-2.5.27/mm/mremap.c Sat Jul 20 12:11:22 2002
+++ linux/mm/mremap.c Sat Jul 20 16:19:35 2002
@@ -1,7 +1,10 @@
/*
- * linux/mm/remap.c
+ * mm/remap.c
*
* (C) Copyright 1996 Linus Torvalds
+ *
+ * Address space accounting code <alan@redhat.com>
+ * (C) Copyright 2002 Red Hat Inc, All Rights Reserved
*/
#include <linux/mm.h>
@@ -18,8 +21,6 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
-extern int vm_enough_memory(long pages);
-
static inline pte_t *get_one_pte_map_nested(struct mm_struct *mm, unsigned long addr)
{
pgd_t * pgd;
@@ -209,7 +210,11 @@
new_vma->vm_ops->open(new_vma);
insert_vm_struct(current->mm, new_vma);
}
- do_munmap(current->mm, addr, old_len);
+ /*
+ * The old VMA has been accounted for,
+ * don't double account
+ */
+ do_munmap(current->mm, addr, old_len, 0);
current->mm->total_vm += new_len >> PAGE_SHIFT;
if (new_vma->vm_flags & VM_LOCKED) {
current->mm->locked_vm += new_len >> PAGE_SHIFT;
@@ -224,6 +229,8 @@
return -ENOMEM;
}
+extern int sysctl_overcommit_memory; /* FIXME!! */
+
/*
* Expand (or shrink) an existing mapping, potentially moving it at the
* same time (controlled by the MREMAP_MAYMOVE flag and available VM space)
@@ -237,6 +244,7 @@
{
struct vm_area_struct *vma;
unsigned long ret = -EINVAL;
+ unsigned long charged = 0;
if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE))
goto out;
@@ -266,16 +274,17 @@
if ((addr <= new_addr) && (addr+old_len) > new_addr)
goto out;
- do_munmap(current->mm, new_addr, new_len);
+ do_munmap(current->mm, new_addr, new_len, 1);
}
/*
* Always allow a shrinking remap: that just unmaps
* the unnecessary pages..
+ * do_munmap does all the needed commit accounting
*/
ret = addr;
if (old_len >= new_len) {
- do_munmap(current->mm, addr+new_len, old_len - new_len);
+ do_munmap(current->mm, addr+new_len, old_len - new_len, 1);
if (!(flags & MREMAP_FIXED) || (new_addr == addr))
goto out;
}
@@ -305,11 +314,14 @@
if ((current->mm->total_vm << PAGE_SHIFT) + (new_len - old_len)
> current->rlim[RLIMIT_AS].rlim_cur)
goto out;
- /* Private writable mapping? Check memory availability.. */
- if ((vma->vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE &&
- !(flags & MAP_NORESERVE) &&
- !vm_enough_memory((new_len - old_len) >> PAGE_SHIFT))
- goto out;
+
+ if (sysctl_overcommit_memory > 1)
+ flags &= ~MAP_NORESERVE;
+ if (vma->vm_flags & VM_ACCOUNT) {
+ charged = (new_len - old_len) >> PAGE_SHIFT;
+ if (!vm_enough_memory(charged))
+ goto out_nc;
+ }
/* old_len exactly to the end of the area..
* And we're not relocating the area.
@@ -356,6 +368,9 @@
ret = move_vma(vma, addr, old_len, new_len, new_addr);
}
out:
+ if (ret & ~PAGE_MASK)
+ vm_unacct_memory(charged);
+out_nc:
return ret;
}
diff -urN linux-2.5.27/mm/shmem.c linux/mm/shmem.c
--- linux-2.5.27/mm/shmem.c Sat Jul 20 12:11:15 2002
+++ linux/mm/shmem.c Sat Jul 20 16:19:35 2002
@@ -5,7 +5,8 @@
* 2000 Transmeta Corp.
* 2000-2001 Christoph Rohland
* 2000-2001 SAP AG
- *
+ * 2002 Red Hat Inc.
+ *
* This file is released under the GPL.
*/
@@ -21,6 +22,7 @@
#include <linux/devfs_fs_kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
+#include <linux/mman.h>
#include <linux/file.h>
#include <linux/swap.h>
#include <linux/pagemap.h>
@@ -358,10 +360,38 @@
up(&info->sem);
}
+static int shmem_notify_change(struct dentry * dentry, struct iattr *attr)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ if (attr->ia_valid & ATTR_SIZE) {
+ /*
+ * Account swap file usage based on new file size
+ */
+ long change = (attr->ia_size>>PAGE_SHIFT) - (inode->i_size >> PAGE_SHIFT);
+
+ if (attr->ia_size > inode->i_size) {
+ if (!vm_enough_memory(change))
+ return -ENOMEM;
+ } else
+ vm_unacct_memory(-change);
+ }
+
+ error = inode_change_ok(inode, attr);
+ if (!error)
+ error = inode_setattr(inode, attr);
+
+ return error;
+}
+
+
static void shmem_delete_inode(struct inode * inode)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
+ vm_unacct_memory((inode->i_size) >> PAGE_SHIFT);
+
inode->i_size = 0;
if (inode->i_op->truncate == shmem_truncate){
spin_lock (&shmem_ilock);
@@ -823,6 +853,7 @@
unsigned long written;
long status;
int err;
+ loff_t maxpos;
if ((ssize_t) count < 0)
return -EINVAL;
@@ -835,12 +866,12 @@
pos = *ppos;
err = -EINVAL;
if (pos < 0)
- goto out;
+ goto out_nc;
err = file->f_error;
if (err) {
file->f_error = 0;
- goto out;
+ goto out_nc;
}
written = 0;
@@ -848,6 +879,15 @@
if (file->f_flags & O_APPEND)
pos = inode->i_size;
+ maxpos = inode->i_size;
+ if (pos + count > inode->i_size) {
+ maxpos = pos + count;
+ if (!vm_enough_memory((maxpos - inode->i_size) >> PAGE_SHIFT)) {
+ err = -ENOMEM;
+ goto out_nc;
+ }
+ }
+
/*
* Check whether we've reached the file size limit.
*/
@@ -937,6 +977,10 @@
err = written ? written : status;
out:
+ /* Short writes give back address space */
+ if (inode->i_size != maxpos)
+ vm_unacct_memory((maxpos - inode->i_size) >> PAGE_SHIFT);
+out_nc:
up(&inode->i_sem);
return err;
fail_write:
@@ -1480,6 +1524,7 @@
static struct inode_operations shmem_inode_operations = {
truncate: shmem_truncate,
+ setattr: shmem_notify_change,
};
static struct inode_operations shmem_dir_inode_operations = {
@@ -1603,12 +1648,11 @@
*/
struct file *shmem_file_setup(char * name, loff_t size)
{
- int error;
+ int error = -ENOMEM;
struct file *file;
struct inode * inode;
struct dentry *dentry, *root;
struct qstr this;
- int vm_enough_memory(long pages);
if (size > (unsigned long long) SHMEM_MAX_BLOCKS << PAGE_CACHE_SHIFT)
return ERR_PTR(-EINVAL);
@@ -1622,7 +1666,7 @@
root = shm_mnt->mnt_root;
dentry = d_alloc(root, &this);
if (!dentry)
- return ERR_PTR(-ENOMEM);
+ goto put_memory;
error = -ENFILE;
file = get_empty_filp();
@@ -1648,6 +1692,8 @@
put_filp(file);
put_dentry:
dput (dentry);
+put_memory:
+ vm_unacct_memory((size) >> PAGE_CACHE_SHIFT);
return ERR_PTR(error);
}
/*
-
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