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120 Commits (43b5e4ccd463a5b42e0531c32628ac462081cab8)
| Author | SHA1 | Message | Date |
|---|---|---|---|
Konstantin Khlebnikov
|
bca1554373 |
proc/smaps: show amount of nonlinear ptes in vma
Currently, nonlinear mappings can not be distinguished from ordinary mappings. This patch adds into /proc/pid/smaps line "Nonlinear: <size> kB", where size is amount of nonlinear ptes in vma, this line appears only if VM_NONLINEAR is set. This information may be useful not only for checkpoint/restore project. Requested by Pavel Emelyanov. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Konstantin Khlebnikov
|
b1d4d9e0cb |
proc/smaps: carefully handle migration entries
Currently smaps reports migration entries as "swap", as result "swap" can appears in shared mapping. This patch converts migration entries into pages and handles them as usual. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Konstantin Khlebnikov
|
052fb0d635 |
proc: report file/anon bit in /proc/pid/pagemap
This is an implementation of Andrew's proposal to extend the pagemap file bits to report what is missing about tasks' working set. The problem with the working set detection is multilateral. In the criu (checkpoint/restore) project we dump the tasks' memory into image files and to do it properly we need to detect which pages inside mappings are really in use. The mincore syscall I though could help with this did not. First, it doesn't report swapped pages, thus we cannot find out which parts of anonymous mappings to dump. Next, it does report pages from page cache as present even if they are not mapped, and it doesn't make that has not been cow-ed. Note, that issue with swap pages is critical -- we must dump swap pages to image file. But the issues with file pages are optimization -- we can take all file pages to image, this would be correct, but if we know that a page is not mapped or not cow-ed, we can remove them from dump file. The dump would still be self-consistent, though significantly smaller in size (up to 10 times smaller on real apps). Andrew noticed, that the proc pagemap file solved 2 of 3 above issues -- it reports whether a page is present or swapped and it doesn't report not mapped page cache pages. But, it doesn't distinguish cow-ed file pages from not cow-ed. I would like to make the last unused bit in this file to report whether the page mapped into respective pte is PageAnon or not. [comment stolen from Pavel Emelyanov's v1 patch] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Cong Wang
|
e7dcd9990e |
proc: remove mm_for_maps()
mm_for_maps() is a simple wrapper for mm_access(), and the name is misleading, so just remove it and use mm_access() directly. Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Sasha Levin
|
08fa29d916 |
mm: fix NULL ptr deref when walking hugepages
A missing validation of the value returned by find_vma() could cause a
NULL ptr dereference when walking the pagetable.
This is triggerable from usermode by a simple user by trying to read a
page info out of /proc/pid/pagemap which doesn't exist.
Introduced by commit
|
13 years ago |
|
Konstantin Khlebnikov
|
16fbdce62d |
proc/pid/pagemap: correctly report non-present ptes and holes between vmas
Reset the current pagemap-entry if the current pte isn't present, or if current vma is over. Otherwise pagemap reports last entry again and again. Non-present pte reporting was broken in commit |
13 years ago |
|
Will Deacon
|
63f61a6f46 |
revert "proc: clear_refs: do not clear reserved pages"
Revert commit |
13 years ago |
|
Naoya Horiguchi
|
10bdfb5ef7 |
pagemap: remove remaining unneeded spin_lock()
Commit
|
13 years ago |
|
Andrea Arcangeli
|
45f83cefe3 |
mm: thp: fix up pmd_trans_unstable() locations
pmd_trans_unstable() should be called before pmd_offset_map() in the locations where the mmap_sem is held for reading. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mark Salter <msalter@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Siddhesh Poyarekar
|
b76437579d |
procfs: mark thread stack correctly in proc/<pid>/maps
Stack for a new thread is mapped by userspace code and passed via
sys_clone. This memory is currently seen as anonymous in
/proc/<pid>/maps, which makes it difficult to ascertain which mappings
are being used for thread stacks. This patch uses the individual task
stack pointers to determine which vmas are actually thread stacks.
For a multithreaded program like the following:
#include <pthread.h>
void *thread_main(void *foo)
{
while(1);
}
int main()
{
pthread_t t;
pthread_create(&t, NULL, thread_main, NULL);
pthread_join(t, NULL);
}
proc/PID/maps looks like the following:
00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out
00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out
019ef000-01a10000 rw-p 00000000 00:00 0 [heap]
7f8a44491000-7f8a44492000 ---p 00000000 00:00 0
7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0
7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00
|
13 years ago |
|
Naoya Horiguchi
|
092b50bacd |
pagemap: introduce data structure for pagemap entry
Currently a local variable of pagemap entry in pagemap_pte_range() is named pfn and typed with u64, but it's not correct (pfn should be unsigned long.) This patch introduces special type for pagemap entries and replaces code with it. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: David Rientjes <rientjes@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Naoya Horiguchi
|
025c5b2451 |
thp: optimize away unnecessary page table locking
Currently when we check if we can handle thp as it is or we need to split it into regular sized pages, we hold page table lock prior to check whether a given pmd is mapping thp or not. Because of this, when it's not "huge pmd" we suffer from unnecessary lock/unlock overhead. To remove it, this patch introduces a optimized check function and replace several similar logics with it. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: David Rientjes <rientjes@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Naoya Horiguchi
|
5aaabe831e |
pagemap: avoid splitting thp when reading /proc/pid/pagemap
Thp split is not necessary if we explicitly check whether pmds are mapping thps or not. This patch introduces this check and adds code to generate pagemap entries for pmds mapping thps, which results in less performance impact of pagemap on thp. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Andrea Arcangeli
|
1a5a9906d4 |
mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode
In some cases it may happen that pmd_none_or_clear_bad() is called with
the mmap_sem hold in read mode. In those cases the huge page faults can
allocate hugepmds under pmd_none_or_clear_bad() and that can trigger a
false positive from pmd_bad() that will not like to see a pmd
materializing as trans huge.
It's not khugepaged causing the problem, khugepaged holds the mmap_sem
in write mode (and all those sites must hold the mmap_sem in read mode
to prevent pagetables to go away from under them, during code review it
seems vm86 mode on 32bit kernels requires that too unless it's
restricted to 1 thread per process or UP builds). The race is only with
the huge pagefaults that can convert a pmd_none() into a
pmd_trans_huge().
Effectively all these pmd_none_or_clear_bad() sites running with
mmap_sem in read mode are somewhat speculative with the page faults, and
the result is always undefined when they run simultaneously. This is
probably why it wasn't common to run into this. For example if the
madvise(MADV_DONTNEED) runs zap_page_range() shortly before the page
fault, the hugepage will not be zapped, if the page fault runs first it
will be zapped.
Altering pmd_bad() not to error out if it finds hugepmds won't be enough
to fix this, because zap_pmd_range would then proceed to call
zap_pte_range (which would be incorrect if the pmd become a
pmd_trans_huge()).
The simplest way to fix this is to read the pmd in the local stack
(regardless of what we read, no need of actual CPU barriers, only
compiler barrier needed), and be sure it is not changing under the code
that computes its value. Even if the real pmd is changing under the
value we hold on the stack, we don't care. If we actually end up in
zap_pte_range it means the pmd was not none already and it was not huge,
and it can't become huge from under us (khugepaged locking explained
above).
All we need is to enforce that there is no way anymore that in a code
path like below, pmd_trans_huge can be false, but pmd_none_or_clear_bad
can run into a hugepmd. The overhead of a barrier() is just a compiler
tweak and should not be measurable (I only added it for THP builds). I
don't exclude different compiler versions may have prevented the race
too by caching the value of *pmd on the stack (that hasn't been
verified, but it wouldn't be impossible considering
pmd_none_or_clear_bad, pmd_bad, pmd_trans_huge, pmd_none are all inlines
and there's no external function called in between pmd_trans_huge and
pmd_none_or_clear_bad).
if (pmd_trans_huge(*pmd)) {
if (next-addr != HPAGE_PMD_SIZE) {
VM_BUG_ON(!rwsem_is_locked(&tlb->mm->mmap_sem));
split_huge_page_pmd(vma->vm_mm, pmd);
} else if (zap_huge_pmd(tlb, vma, pmd, addr))
continue;
/* fall through */
}
if (pmd_none_or_clear_bad(pmd))
Because this race condition could be exercised without special
privileges this was reported in CVE-2012-1179.
The race was identified and fully explained by Ulrich who debugged it.
I'm quoting his accurate explanation below, for reference.
====== start quote =======
mapcount 0 page_mapcount 1
kernel BUG at mm/huge_memory.c:1384!
At some point prior to the panic, a "bad pmd ..." message similar to the
following is logged on the console:
mm/memory.c:145: bad pmd ffff8800376e1f98(80000000314000e7).
The "bad pmd ..." message is logged by pmd_clear_bad() before it clears
the page's PMD table entry.
143 void pmd_clear_bad(pmd_t *pmd)
144 {
-> 145 pmd_ERROR(*pmd);
146 pmd_clear(pmd);
147 }
After the PMD table entry has been cleared, there is an inconsistency
between the actual number of PMD table entries that are mapping the page
and the page's map count (_mapcount field in struct page). When the page
is subsequently reclaimed, __split_huge_page() detects this inconsistency.
1381 if (mapcount != page_mapcount(page))
1382 printk(KERN_ERR "mapcount %d page_mapcount %d\n",
1383 mapcount, page_mapcount(page));
-> 1384 BUG_ON(mapcount != page_mapcount(page));
The root cause of the problem is a race of two threads in a multithreaded
process. Thread B incurs a page fault on a virtual address that has never
been accessed (PMD entry is zero) while Thread A is executing an madvise()
system call on a virtual address within the same 2 MB (huge page) range.
virtual address space
.---------------------.
| |
| |
.-|---------------------|
| | |
| | |<-- B(fault)
| | |
2 MB | |/////////////////////|-.
huge < |/////////////////////| > A(range)
page | |/////////////////////|-'
| | |
| | |
'-|---------------------|
| |
| |
'---------------------'
- Thread A is executing an madvise(..., MADV_DONTNEED) system call
on the virtual address range "A(range)" shown in the picture.
sys_madvise
// Acquire the semaphore in shared mode.
down_read(¤t->mm->mmap_sem)
...
madvise_vma
switch (behavior)
case MADV_DONTNEED:
madvise_dontneed
zap_page_range
unmap_vmas
unmap_page_range
zap_pud_range
zap_pmd_range
//
// Assume that this huge page has never been accessed.
// I.e. content of the PMD entry is zero (not mapped).
//
if (pmd_trans_huge(*pmd)) {
// We don't get here due to the above assumption.
}
//
// Assume that Thread B incurred a page fault and
.---------> // sneaks in here as shown below.
| //
| if (pmd_none_or_clear_bad(pmd))
| {
| if (unlikely(pmd_bad(*pmd)))
| pmd_clear_bad
| {
| pmd_ERROR
| // Log "bad pmd ..." message here.
| pmd_clear
| // Clear the page's PMD entry.
| // Thread B incremented the map count
| // in page_add_new_anon_rmap(), but
| // now the page is no longer mapped
| // by a PMD entry (-> inconsistency).
| }
| }
|
v
- Thread B is handling a page fault on virtual address "B(fault)" shown
in the picture.
...
do_page_fault
__do_page_fault
// Acquire the semaphore in shared mode.
down_read_trylock(&mm->mmap_sem)
...
handle_mm_fault
if (pmd_none(*pmd) && transparent_hugepage_enabled(vma))
// We get here due to the above assumption (PMD entry is zero).
do_huge_pmd_anonymous_page
alloc_hugepage_vma
// Allocate a new transparent huge page here.
...
__do_huge_pmd_anonymous_page
...
spin_lock(&mm->page_table_lock)
...
page_add_new_anon_rmap
// Here we increment the page's map count (starts at -1).
atomic_set(&page->_mapcount, 0)
set_pmd_at
// Here we set the page's PMD entry which will be cleared
// when Thread A calls pmd_clear_bad().
...
spin_unlock(&mm->page_table_lock)
The mmap_sem does not prevent the race because both threads are acquiring
it in shared mode (down_read). Thread B holds the page_table_lock while
the page's map count and PMD table entry are updated. However, Thread A
does not synchronize on that lock.
====== end quote =======
[akpm@linux-foundation.org: checkpatch fixes]
Reported-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Jones <davej@redhat.com>
Acked-by: Larry Woodman <lwoodman@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: <stable@vger.kernel.org> [2.6.38+]
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
13 years ago |
|
Will Deacon
|
85e72aa538 |
proc: clear_refs: do not clear reserved pages
/proc/pid/clear_refs is used to clear the Referenced and YOUNG bits for
pages and corresponding page table entries of the task with PID pid, which
includes any special mappings inserted into the page tables in order to
provide things like vDSOs and user helper functions.
On ARM this causes a problem because the vectors page is mapped as a
global mapping and since
|
13 years ago |
|
Christoph Lameter
|
bc3e53f682 |
mm: distinguish between mlocked and pinned pages
Some kernel components pin user space memory (infiniband and perf) (by increasing the page count) and account that memory as "mlocked". The difference between mlocking and pinning is: A. mlocked pages are marked with PG_mlocked and are exempt from swapping. Page migration may move them around though. They are kept on a special LRU list. B. Pinned pages cannot be moved because something needs to directly access physical memory. They may not be on any LRU list. I recently saw an mlockalled process where mm->locked_vm became bigger than the virtual size of the process (!) because some memory was accounted for twice: Once when the page was mlocked and once when the Infiniband layer increased the refcount because it needt to pin the RDMA memory. This patch introduces a separate counter for pinned pages and accounts them seperately. Signed-off-by: Christoph Lameter <cl@linux.com> Cc: Mike Marciniszyn <infinipath@qlogic.com> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Andrew Morton
|
fc360bd9cd |
/proc/self/numa_maps: restore "huge" tag for hugetlb vmas
The display of the "huge" tag was accidentally removed in
|
13 years ago |
|
Dave Hansen
|
32ef43848f |
teach /proc/$pid/numa_maps about transparent hugepages
This is modeled after the smaps code. It detects transparent hugepages and then does a single gather_stats() for the page as a whole. This has two benifits: 1. It is more efficient since it does many pages in a single shot. 2. It does not have to break down the huge page. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Dave Hansen
|
3200a8aaab |
break out numa_maps gather_pte_stats() checks
gather_pte_stats() does a number of checks on a target page to see whether it should even be considered for statistics. This breaks that code out in to a separate function so that we can use it in the transparent hugepage case in the next patch. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: Christoph Lameter <cl@gentwo.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Dave Hansen
|
eb4866d006 |
make /proc/$pid/numa_maps gather_stats() take variable page size
We need to teach the numa_maps code about transparent huge pages. The first step is to teach gather_stats() that the pte it is dealing with might represent more than one page. Note that will we use this in a moment for transparent huge pages since they have use a single pmd_t which _acts_ as a "surrogate" for a bunch of smaller pte_t's. I'm a _bit_ unhappy that this interface counts in hugetlbfs page sizes for hugetlbfs pages and PAGE_SIZE for normal pages. That means that to figure out how many _bytes_ "dirty=1" means, you must first know the hugetlbfs page size. That's easier said than done especially if you don't have visibility in to the mount. But, that's probably a discussion for another day especially since it would change behavior to fix it. But, just in case anyone wonders why this patch only passes a '1' in the hugetlb case... Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
KOSAKI Motohiro
|
98bc93e505 |
proc: fix pagemap_read() error case
Currently, pagemap_read() has three error and/or corner case handling
mistake.
(1) If ppos parameter is wrong, mm refcount will be leak.
(2) If count parameter is 0, mm refcount will be leak too.
(3) If the current task is sleeping in kmalloc() and the system
is out of memory and oom-killer kill the proc associated task,
mm_refcount prevent the task free its memory. then system may
hang up.
<Quote Hugh's explain why we shold call kmalloc() before get_mm()>
check_mem_permission gets a reference to the mm. If we
__get_free_page after check_mem_permission, imagine what happens if the
system is out of memory, and the mm we're looking at is selected for
killing by the OOM killer: while we wait in __get_free_page for more
memory, no memory is freed from the selected mm because it cannot reach
exit_mmap while we hold that reference.
This patch fixes the above three.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jovi Zhang <bookjovi@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Stephen Wilson <wilsons@start.ca>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
14 years ago |
|
Alexey Dobriyan
|
0a8cb8e341 |
fs/proc: convert to kstrtoX()
Convert fs/proc/ from strict_strto*() to kstrto*() functions. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
KOSAKI Motohiro
|
ca16d140af |
mm: don't access vm_flags as 'int'
The type of vma->vm_flags is 'unsigned long'. Neither 'int' nor 'unsigned int'. This patch fixes such misuse. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> [ Changed to use a typedef - we'll extend it to cover more cases later, since there has been discussion about making it a 64-bit type.. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Stephen Wilson
|
5b52fc890b |
proc: allocate storage for numa_maps statistics once
In show_numa_map() we collect statistics into a numa_maps structure. Since the number of NUMA nodes can be very large, this structure is not a candidate for stack allocation. Instead of going thru a kmalloc()+kfree() cycle each time show_numa_map() is invoked, perform the allocation just once when /proc/pid/numa_maps is opened. Performing the allocation when numa_maps is opened, and thus before a reference to the target tasks mm is taken, eliminates a potential stalemate condition in the oom-killer as originally described by Hugh Dickins: ... imagine what happens if the system is out of memory, and the mm we're looking at is selected for killing by the OOM killer: while we wait in __get_free_page for more memory, no memory is freed from the selected mm because it cannot reach exit_mmap while we hold that reference. Signed-off-by: Stephen Wilson <wilsons@start.ca> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Stephen Wilson
|
f69ff943df |
mm: proc: move show_numa_map() to fs/proc/task_mmu.c
Moving show_numa_map() from mempolicy.c to task_mmu.c solves several
issues.
- Having the show() operation "miles away" from the corresponding
seq_file iteration operations is a maintenance burden.
- The need to export ad hoc info like struct proc_maps_private is
eliminated.
- The implementation of show_numa_map() can be improved in a simple
manner by cooperating with the other seq_file operations (start,
stop, etc) -- something that would be messy to do without this
change.
Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
14 years ago |
|
Mikulas Patocka
|
a09a79f668 |
Don't lock guardpage if the stack is growing up
Linux kernel excludes guard page when performing mlock on a VMA with down-growing stack. However, some architectures have up-growing stack and locking the guard page should be excluded in this case too. This patch fixes lvm2 on PA-RISC (and possibly other architectures with up-growing stack). lvm2 calculates number of used pages when locking and when unlocking and reports an internal error if the numbers mismatch. [ Patch changed fairly extensively to also fix /proc/<pid>/maps for the grows-up case, and to move things around a bit to clean it all up and share the infrstructure with the /proc bits. Tested on ia64 that has both grow-up and grow-down segments - Linus ] Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Tested-by: Tony Luck <tony.luck@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Linus Torvalds
|
76597cd314 |
proc: fix oops on invalid /proc/<pid>/maps access
When m_start returns an error, the seq_file logic will still call m_stop
with that error entry, so we'd better make sure that we check it before
using it as a vma.
Introduced by commit
|
14 years ago |
|
Aaro Koskinen
|
0db0c01b53 |
procfs: fix /proc/<pid>/maps heap check
The current code fails to print the "[heap]" marking if the heap is split
into multiple mappings.
Fix the check so that the marking is displayed in all possible cases:
1. vma matches exactly the heap
2. the heap vma is merged e.g. with bss
3. the heap vma is splitted e.g. due to locked pages
Test cases. In all cases, the process should have mapping(s) with
[heap] marking:
(1) vma matches exactly the heap
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
int main (void)
{
if (sbrk(4096) != (void *)-1) {
printf("check /proc/%d/maps\n", (int)getpid());
while (1)
sleep(1);
}
return 0;
}
# ./test1
check /proc/553/maps
[1] + Stopped ./test1
# cat /proc/553/maps | head -4
00008000-00009000 r-xp 00000000 01:00 3113640 /test1
00010000-00011000 rw-p 00000000 01:00 3113640 /test1
00011000-00012000 rw-p 00000000 00:00 0 [heap]
4006f000-40070000 rw-p 00000000 00:00 0
(2) the heap vma is merged
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
char foo[4096] = "foo";
char bar[4096];
int main (void)
{
if (sbrk(4096) != (void *)-1) {
printf("check /proc/%d/maps\n", (int)getpid());
while (1)
sleep(1);
}
return 0;
}
# ./test2
check /proc/556/maps
[2] + Stopped ./test2
# cat /proc/556/maps | head -4
00008000-00009000 r-xp 00000000 01:00 3116312 /test2
00010000-00012000 rw-p 00000000 01:00 3116312 /test2
00012000-00014000 rw-p 00000000 00:00 0 [heap]
4004a000-4004b000 rw-p 00000000 00:00 0
(3) the heap vma is splitted (this fails without the patch)
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
int main (void)
{
if ((sbrk(4096) != (void *)-1) && !mlockall(MCL_FUTURE) &&
(sbrk(4096) != (void *)-1)) {
printf("check /proc/%d/maps\n", (int)getpid());
while (1)
sleep(1);
}
return 0;
}
# ./test3
check /proc/559/maps
[1] + Stopped ./test3
# cat /proc/559/maps|head -4
00008000-00009000 r-xp 00000000 01:00 3119108 /test3
00010000-00011000 rw-p 00000000 01:00 3119108 /test3
00011000-00012000 rw-p 00000000 00:00 0 [heap]
00012000-00013000 rw-p 00000000 00:00 0 [heap]
It looks like the bug has been there forever, and since it only results in
some information missing from a procfile, it does not fulfil the -stable
"critical issue" criteria.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
14 years ago |
|
Stephen Wilson
|
31db58b3ab |
mm: arch: make get_gate_vma take an mm_struct instead of a task_struct
Morally, the presence of a gate vma is more an attribute of a particular mm than a particular task. Moreover, dropping the dependency on task_struct will help make both existing and future operations on mm's more flexible and convenient. Signed-off-by: Stephen Wilson <wilsons@start.ca> Reviewed-by: Michel Lespinasse <walken@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
14 years ago |
|
Al Viro
|
ec6fd8a435 |
report errors in /proc/*/*map* sanely
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
14 years ago |
|
Al Viro
|
ca6b0bf0e0 |
pagemap: close races with suid execve
just use mm_for_maps() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
14 years ago |
|
Dave Hansen
|
4031a219d8 |
smaps: have smaps show transparent huge pages
Now that the mere act of _looking_ at /proc/$pid/smaps will not destroy transparent huge pages, tell how much of the VMA is actually mapped with them. This way, we can make sure that we're getting THPs where we expect to see them. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Dave Hansen
|
22e057c592 |
smaps: teach smaps_pte_range() about THP pmds
This adds code to explicitly detect and handle pmd_trans_huge() pmds. It then passes HPAGE_SIZE units in to the smap_pte_entry() function instead of PAGE_SIZE. This means that using /proc/$pid/smaps now will no longer cause THPs to be broken down in to small pages. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Reviewed-by: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Dave Hansen
|
3c9acc7849 |
smaps: pass pte size argument in to smaps_pte_entry()
Add an argument to the new smaps_pte_entry() function to let it account in things other than PAGE_SIZE units. I changed all of the PAGE_SIZE sites, even though not all of them can be reached for transparent huge pages, just so this will continue to work without changes as THPs are improved. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Dave Hansen
|
ae11c4d9f6 |
smaps: break out smaps_pte_entry() from smaps_pte_range()
We will use smaps_pte_entry() in a moment to handle both small and transparent large pages. But, we must break it out of smaps_pte_range() first. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Dave Hansen
|
033193275b |
pagewalk: only split huge pages when necessary
Right now, if a mm_walk has either ->pte_entry or ->pmd_entry set, it will unconditionally split any transparent huge pages it runs in to. In practice, that means that anyone doing a cat /proc/$pid/smaps will unconditionally break down every huge page in the process and depend on khugepaged to re-collapse it later. This is fairly suboptimal. This patch changes that behavior. It teaches each ->pmd_entry handler (there are five) that they must break down the THPs themselves. Also, the _generic_ code will never break down a THP unless a ->pte_entry handler is actually set. This means that the ->pmd_entry handlers can now choose to deal with THPs without breaking them down. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Nikanth Karthikesan
|
2d90508f63 |
mm: smaps: export mlock information
Currently there is no way to find whether a process has locked its pages in memory or not. And which of the memory regions are locked in memory. Add a new field "Locked" to export this information via the smaps file. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Alexey Dobriyan
|
a2ade7b6ca |
proc: use unsigned long inside /proc/*/statm
/proc/*/statm code needlessly truncates data from unsigned long to int. One needs only 8+ TB of RAM to make truncation visible. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Naoya Horiguchi
|
ea251c1d5c |
pagemap: set pagemap walk limit to PMD boundary
Currently one pagemap_read() call walks in PAGEMAP_WALK_SIZE bytes (== 512 pages.) But there is a corner case where walk_pmd_range() accidentally runs over a VMA associated with a hugetlbfs file. For example, when a process has mappings to VMAs as shown below: # cat /proc/<pid>/maps ... 3a58f6d000-3a58f72000 rw-p 00000000 00:00 0 7fbd51853000-7fbd51855000 rw-p 00000000 00:00 0 7fbd5186c000-7fbd5186e000 rw-p 00000000 00:00 0 7fbd51a00000-7fbd51c00000 rw-s 00000000 00:12 8614 /hugepages/test then pagemap_read() goes into walk_pmd_range() path and walks in the range 0x7fbd51853000-0x7fbd51a53000, but the hugetlbfs VMA should be handled by walk_hugetlb_range(). Otherwise PMD for the hugepage is considered bad and cleared, which causes undesirable results. This patch fixes it by separating pagemap walk range into one PMD. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Nikanth Karthikesan
|
b40d4f84be |
/proc/pid/smaps: export amount of anonymous memory in a mapping
Export the number of anonymous pages in a mapping via smaps. Even the private pages in a mapping backed by a file, would be marked as anonymous, when they are modified. Export this information to user-space via smaps. Exporting this count will help gdb to make a better decision on which areas need to be dumped in its coredump; and should be useful to others studying the memory usage of a process. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
|
Arnd Bergmann
|
6038f373a3 |
llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.
The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.
New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.
The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.
Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.
Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.
===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}
@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}
@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};
@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};
@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};
@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};
@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};
// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};
@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};
// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};
// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};
// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};
@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};
// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////
@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};
@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};
@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};
@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
|
15 years ago |
|
KOSAKI Motohiro
|
1c2499ae87 |
/proc/pid/smaps: fix dirty pages accounting
Currently, /proc/<pid>/smaps has wrong dirty pages accounting.
Shared_Dirty and Private_Dirty output only pte dirty pages and ignore
PG_dirty page flag. It is difference against documentation, but also
inconsistent against Referenced field. (Referenced checks both pte and
page flags)
This patch fixes it.
Test program:
large-array.c
---------------------------------------------------
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
char array[1*1024*1024*1024L];
int main(void)
{
memset(array, 1, sizeof(array));
pause();
return 0;
}
---------------------------------------------------
Test case:
1. run ./large-array
2. cat /proc/`pidof large-array`/smaps
3. swapoff -a
4. cat /proc/`pidof large-array`/smaps again
Test result:
<before patch>
00601000-40601000 rw-p 00000000 00:00 0
Size: 1048576 kB
Rss: 1048576 kB
Pss: 1048576 kB
Shared_Clean: 0 kB
Shared_Dirty: 0 kB
Private_Clean: 218992 kB <-- showed pages as clean incorrectly
Private_Dirty: 829584 kB
Referenced: 388364 kB
Swap: 0 kB
KernelPageSize: 4 kB
MMUPageSize: 4 kB
<after patch>
00601000-40601000 rw-p 00000000 00:00 0
Size: 1048576 kB
Rss: 1048576 kB
Pss: 1048576 kB
Shared_Clean: 0 kB
Shared_Dirty: 0 kB
Private_Clean: 0 kB
Private_Dirty: 1048576 kB <-- fixed
Referenced: 388480 kB
Swap: 0 kB
KernelPageSize: 4 kB
MMUPageSize: 4 kB
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
15 years ago |
|
Stefan Bader
|
39aa3cb3e8 |
mm: Move vma_stack_continue into mm.h
So it can be used by all that need to check for that. Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
15 years ago |
|
Linus Torvalds
|
d7824370e2 |
mm: fix up some user-visible effects of the stack guard page
This commit makes the stack guard page somewhat less visible to user space. It does this by: - not showing the guard page in /proc/<pid>/maps It looks like lvm-tools will actually read /proc/self/maps to figure out where all its mappings are, and effectively do a specialized "mlockall()" in user space. By not showing the guard page as part of the mapping (by just adding PAGE_SIZE to the start for grows-up pages), lvm-tools ends up not being aware of it. - by also teaching the _real_ mlock() functionality not to try to lock the guard page. That would just expand the mapping down to create a new guard page, so there really is no point in trying to lock it in place. It would perhaps be nice to show the guard page specially in /proc/<pid>/maps (or at least mark grow-down segments some way), but let's not open ourselves up to more breakage by user space from programs that depends on the exact deails of the 'maps' file. Special thanks to Henrique de Moraes Holschuh for diving into lvm-tools source code to see what was going on with the whole new warning. Reported-and-tested-by: François Valenduc <francois.valenduc@tvcablenet.be Reported-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
15 years ago |
|
Naoya Horiguchi
|
1a5cb81465 |
pagemap: add #ifdefs CONFIG_HUGETLB_PAGE on code walking hugetlb vma
If !CONFIG_HUGETLB_PAGE, pagemap_hugetlb_range() is never called. So put it (and its calling function) into #ifdef block. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
15 years ago |
|
Robin Holt
|
34441427aa |
revert "procfs: provide stack information for threads" and its fixup commits
Originally, commit |
15 years ago |
|
Naoya Horiguchi
|
116354d177 |
pagemap: fix pfn calculation for hugepage
When we look into pagemap using page-types with option -p, the value of
pfn for hugepages looks wrong (see below.) This is because pte was
evaluated only once for one vma although it should be updated for each
hugepage. This patch fixes it.
$ page-types -p 3277 -Nl -b huge
voffset offset len flags
7f21e8a00 11e400 1 ___U___________H_G________________
7f21e8a01 11e401 1ff ________________TG________________
^^^
7f21e8c00 11e400 1 ___U___________H_G________________
7f21e8c01 11e401 1ff ________________TG________________
^^^
One hugepage contains 1 head page and 511 tail pages in x86_64 and each
two lines represent each hugepage. Voffset and offset mean virtual
address and physical address in the page unit, respectively. The
different hugepages should not have the same offset value.
With this patch applied:
$ page-types -p 3386 -Nl -b huge
voffset offset len flags
7fec7a600 112c00 1 ___UD__________H_G________________
7fec7a601 112c01 1ff ________________TG________________
^^^
7fec7a800 113200 1 ___UD__________H_G________________
7fec7a801 113201 1ff ________________TG________________
^^^
OK
More info:
- This patch modifies walk_page_range()'s hugepage walker. But the
change only affects pagemap_read(), which is the only caller of hugepage
callback.
- Without this patch, hugetlb_entry() callback is called per vma, that
doesn't match the natural expectation from its name.
- With this patch, hugetlb_entry() is called per hugepte entry and the
callback can become much simpler.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
15 years ago |
|
Dan Carpenter
|
309361e09c |
proc: copy_to_user() returns unsigned
copy_to_user() returns the number of bytes left to be copied.
This was a typo from:
|
15 years ago |
|
KAMEZAWA Hiroyuki
|
d82ef020cf |
proc: pagemap: Hold mmap_sem during page walk
In initial design, walk_page_range() was designed just for walking page table and it didn't require mmap_sem. Now, find_vma() etc.. are used in walk_page_range() and we need mmap_sem around it. This patch adds mmap_sem around walk_page_range(). Because /proc/<pid>/pagemap's callback routine use put_user(), we have to get rid of it to do sane fix. Changelog: 2010/Apr/2 - fixed start_vaddr and end overflow Changelog: 2010/Apr/1 - fixed start_vaddr calculation - removed unnecessary cast. - removed unnecessary change in smaps. - use GFP_TEMPORARY instead of GFP_KERNEL Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Matt Mackall <mpm@selenic.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: San Mehat <san@google.com> Cc: Brian Swetland <swetland@google.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> [ Fixed kmalloc failure return code as per Matt ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
15 years ago |
|
Tejun Heo
|
5a0e3ad6af |
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> |
15 years ago |