答复: Re: Bug 15321 - malloc/free can't give the memory back to kernel when main_arena is discontinous
Commit Message
yes, covered by the one for "Chengdu Zhongxing Software Company Limited (ZTE)" dated 23 August 2018.
I have added the copyright notice in the tst-discontinuous-main-arena.c
The new patch:
2018-11-28 Hehongjun <He.Hongjun@zte.com.cn>
[BZ #15321]
* malloc/Makefile: add tst-discontinuous-main-arena.
* malloc/arena.c (heap_trim): add main arean
* malloc/malloc.c: modify discontinuous main arena
with sysmalloc, modify discontinuous main arena link heap.
with _int_free, free memory on discontinuous main arena link heap.
* malloc/tst-discontinuous-main-arena: New test.
------------------原始邮件------------------
发件人：JosephMyers <joseph@codesourcery.com>
收件人：贺洪军10036572;
抄送人：libc-alpha@sourceware.org <libc-alpha@sourceware.org>;
日 期 ：2018年11月30日 01:24
主 题 ：Re: Bug 15321 - malloc/free can't give the memory back to kernel when main_arena is discontinous
On Thu, 29 Nov 2018, He.Hongjun@zte.com.cn wrote:
> Hello, I have fixed the Bug 15321.
> patch on glibc-2.28
Do you have an FSF copyright assignment? (Are you covered by the one for
"Chengdu Zhongxing Software Company Limited (ZTE)" dated 23 August 2018?)
> diff --git a/malloc/tst-discontinuous-main-arena.c b/malloc/tst-discontinuous-main-arena.c
> old mode 100644
> new mode 100755
> index e69de29..3f6f0e7
> --- a/malloc/tst-discontinuous-main-arena.c
> +++ b/malloc/tst-discontinuous-main-arena.c
> @@ -0,0 +1,128 @@
> +/* Ensure that main arena of discontinuity can normal free memory.
> +
> + The GNU C Library is free software; you can redistribute it and/or
Missing copyright notice, before the license notice.
> +#define TEST_FUNCTION do_test ()
> +#include "../test-skeleton.c"
New tests should use <support/test-driver.c>, not the old-style
test-skeleton.c.
--
Joseph S. Myers
joseph@codesourcery.com
Comments
On 11/29/18 8:08 PM, He.Hongjun@zte.com.cn wrote:
> yes, covered by the one for "Chengdu Zhongxing Software Company Limited (ZTE)" dated 23 August 2018.
>
> I have added the copyright notice in the tst-discontinuous-main-arena.c
I look forward to a v2.
(1) Include a detailed description of your changes.
At a high level can you describe what the patch does and
what it fixes? Such a description is required for the
git commit message and is an important part of establishing
the intentions of your technical change. A reviewer, like
myself, can then review that the code matches your high-level
itent (or design).
(2) Please attach the patch to the next email.
While the contribution checklist says there is a strong preference
to inline the patch in our email, this sometimes breaks the patch
because MUAs may convert tabs and spaces or wrap lines. For v2,
I suggest you commit your code to your local git repo, and then
send us `git format-patch HEAD~1` which will show us everything
you *would* have committed when you push the patch. This lets me
review everything including the commit message.
> 2018-11-28 Hehongjun <He.Hongjun@zte.com.cn>
>
> [BZ #15321]
> * malloc/Makefile: add tst-discontinuous-main-arena.
> * malloc/arena.c (heap_trim): add main arean
> * malloc/malloc.c: modify discontinuous main arena
> with sysmalloc, modify discontinuous main arena link heap.
> with _int_free, free memory on discontinuous main arena link heap.
> * malloc/tst-discontinuous-main-arena: New test.
>
> diff --git a/malloc/Makefile b/malloc/Makefile
> index 7d54bad..9d60ab1 100644
> --- a/malloc/Makefile
> +++ b/malloc/Makefile
> @@ -38,6 +38,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
> tst-malloc_info \
> tst-malloc-too-large \
> tst-malloc-stats-cancellation \
> + tst-discontinuous-main-arena \
I think this is the wrong place to put this test, see notes bleow.
>
> tests-static := \
> tst-interpose-static-nothread \
> diff --git a/malloc/arena.c b/malloc/arena.c
> index 497ae47..343ef13 100755
> --- a/malloc/arena.c
> +++ b/malloc/arena.c
> @@ -634,6 +634,45 @@ heap_trim (heap_info *heap, size_t pad)
> /*check_chunk(ar_ptr, top_chunk);*/
> }
>
> + if (ar_ptr == &main_arena && heap->prev == NULL)
> + {
> + char *old_top;
> + old_top = (char *) (heap + 1);
> + p = (mchunkptr) (old_top + sizeof (unsigned long));
> +
> + misalign = (unsigned long) chunk2mem (p) & MALLOC_ALIGN_MASK;
> + if (misalign > 0)
> + p = ((char *) p) + MALLOC_ALIGNMENT - misalign;
> +
> + if (top_chunk == (mchunkptr) p)
> + {
> + p = (mchunkptr) (*(unsigned long *) old_top);
> + p = prev_chunk (p);
> + new_size = chunksize (p) + MINSIZE;
> +
> + if (!prev_inuse (p))
> + new_size += prev_size (p);
> +
> + if (new_size >= pad + MINSIZE + pagesz)
> + {
> + ar_ptr->system_mem -= heap->size;
> + delete_heap (heap);
> + if (!prev_inuse (p)) { /* consolidate backward */
> + p = prev_chunk (p);
> + unlink (ar_ptr, p, bck, fwd);
> + }
> +
> + top (ar_ptr) = top_chunk = (char *) p - 2 * SIZE_SZ;
> + set_head (top_chunk, new_size | PREV_INUSE);
> +
> + set_contiguous (ar_ptr);
> + if ((unsigned long)(chunksize (ar_ptr->top)) >= (unsigned long)mp_.trim_threshold)
> + systrim (mp_.trim_threshold, ar_ptr);
> + return 0;
> + }
> + }
> + }
> +
I need to spend some time reviewing this and matching it
with your intent. So I'll wait for v2 to review this.
> /* Uses similar logic for per-thread arenas as the main arena with systrim
> and _int_free by preserving the top pad and rounding down to the nearest
> page. */
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index e247c77..ad53ef7 100755
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -2388,7 +2388,7 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
> assert ((unsigned long) (old_size) < (unsigned long) (nb + MINSIZE));
>
>
> - if (av != &main_arena)
> + if ((av != &main_arena) || (av == &main_arena && !contiguous (av)))
> {
> heap_info *old_heap, *heap;
> size_t old_heap_size;
> @@ -2438,8 +2438,6 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
> goto try_mmap;
> }
> else /* av == main_arena */
> -
> -
Please avoid any white space changes which are not related to the
change you are making.
Please feel free to submit another patch to fix this independently
of the change.
> { /* Request enough space for nb + pad + overhead */
> size = nb + mp_.top_pad + MINSIZE;
>
> @@ -2491,35 +2489,62 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
> and threshold limits, since the space will not be used as a
> segregated mmap region.
> */
> -
> - /* Cannot merge with old top, so add its size back in */
> - if (contiguous (av))
> - size = ALIGN_UP (size + old_size, pagesize);
> -
> - /* If we are relying on mmap as backup, then use larger units */
> - if ((unsigned long) (size) < (unsigned long) (MMAP_AS_MORECORE_SIZE))
> - size = MMAP_AS_MORECORE_SIZE;
> -
> - /* Don't try if size wraps around 0 */
> - if ((unsigned long) (size) > (unsigned long) (nb))
> - {
> - char *mbrk = (char *) (MMAP (0, size, PROT_READ | PROT_WRITE, 0));
> -
> - if (mbrk != MAP_FAILED)
> + heap_info *heap;
> + long misalign;
> + char *ptr;
> + heap = new_heap (nb + (MINSIZE + sizeof (*heap) + MALLOC_ALIGNMENT), mp_.top_pad);
> + if (!heap)
> + {
> + if (!tried_mmap)
> + goto try_mmap;
> + else
> {
> - /* We do not need, and cannot use, another sbrk call to find end */
> - brk = mbrk;
> - snd_brk = brk + size;
> + __set_errno (ENOMEM);
> + return 0;
> + }
> + }
> +
> + heap->ar_ptr = av;
> + heap->prev = NULL;
> + av->system_mem += heap->size;
> +
> + ptr = (char *) (heap + 1);
> + ptr += sizeof (unsigned long);
> + misalign = (unsigned long) chunk2mem (ptr) & MALLOC_ALIGN_MASK;
> + if (misalign > 0)
> + ptr += MALLOC_ALIGNMENT - misalign;
> + /* Set up the new top. */
> + top (av) = ptr;
> + set_head (top (av), (((char *) heap + heap->size) - ptr) | PREV_INUSE);
>
> - /*
> - Record that we no longer have a contiguous sbrk region.
> - After the first time mmap is used as backup, we do not
> - ever rely on contiguous space since this could incorrectly
> - bridge regions.
> - */
> - set_noncontiguous (av);
> - }
> + /* Setup fencepost and free the old top chunk with a multiple of
> + MALLOC_ALIGNMENT in size. */
> + /* The fencepost takes at least MINSIZE bytes, because it might
> + become the top chunk again later. Note that a footer is set
> + up, too, although the chunk is marked in use. */
> + old_size = (old_size - MINSIZE) & ~MALLOC_ALIGN_MASK;
> + set_head (chunk_at_offset (old_top, old_size + 2 * SIZE_SZ), 0 | PREV_INUSE);
> + *(unsigned long *)((heap + 1)) = chunk_at_offset (old_top, old_size + 2 * SIZE_SZ);
> + if (old_size >= MINSIZE)
> + {
> + set_head (chunk_at_offset (old_top, old_size), (2 * SIZE_SZ) | PREV_INUSE);
> + set_foot (chunk_at_offset (old_top, old_size), (2 * SIZE_SZ));
> + set_head (old_top, old_size | PREV_INUSE);
> + _int_free (av, old_top, 1);
> + }
> + else
> + {
> + set_head (old_top, (old_size + 2 * SIZE_SZ) | PREV_INUSE);
> + set_foot (old_top, (old_size + 2 * SIZE_SZ));
> }
> +
> + /*
> + Record that we no longer have a contiguous sbrk region.
> + After the first time mmap is used as backup, we do not
> + ever rely on contiguous space since this could incorrectly
> + bridge regions.
> + */
> + set_noncontiguous (av);
Again, this needs more review and I'll try to get to that in your v2.
> }
>
> if (brk != (char *) (MORECORE_FAILURE))
> @@ -4347,7 +4372,7 @@ _int_free (mstate av, mchunkptr p, int have_lock)
> if (atomic_load_relaxed (&av->have_fastchunks))
> malloc_consolidate(av);
>
> - if (av == &main_arena) {
> + if ((av == &main_arena ) && contiguous (av)) {
> #ifndef MORECORE_CANNOT_TRIM
> if ((unsigned long)(chunksize(av->top)) >=
> (unsigned long)(mp_.trim_threshold))
> diff --git a/malloc/tst-discontinuous-main-arena.c b/malloc/tst-discontinuous-main-arena.c
> old mode 100644
> new mode 100755
> index e69de29..ef7249f
> --- a/malloc/tst-discontinuous-main-arena.c
> +++ b/malloc/tst-discontinuous-main-arena.c
This file is linux-specific and parses /proc/self/statm.
I suggest:
sysdeps/unix/sysv/linux/tst-discontig-main-arena.c
Add it to:
sysdeps/unix/sysv/linux/Makefile
here (around line 10):
~~~
...
ifeq ($(subdir),malloc)
CFLAGS-malloc.c += -DMORECORE_CLEARS=2
tests += tst-discontig-main-arena
endif
...
~~~
> @@ -0,0 +1,133 @@
It should look like this:
/* <One sentence description.>
<Copyright line, with 2018 only because this is a new test.>
<Rest of the license> */
We no longer use 'Contributed by' lines, we rely on ChangeLogs and
git commit messages to provide attribution.
I suggest:
/* Test that a discontinuous main arena can free through the gap.
Copyright (C) 2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
> +/* Copyright (C) 1999-2018 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> + Contributed by He.Hongjun@zte.com.cn, 2018.
> +
> + Ensure that main arena of discontinuity can normal free memory.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public License as
> + published by the Free Software Foundation; either version 2.1 of the
> + License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; see the file COPYING.LIB. If
> + not, see <http://www.gnu.org/licenses/>. */
> +
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/mman.h>
> +
> +#define MEM_SIZE 1024*128
This isn't a size, but rather a count? Should we call it BLK_COUNT?
> +#define BLK_SIZE 1024
> +#define TOP_PAD_SIZE 1024 * 128
> +
Test needs a block comment at the top explaining in detail the intent of the test.
> +static int
> +do_test (void)
> +{
> + /* Get the peak physical memory usage. */
> + FILE *f;
> + unsigned n_rss = 0;
> + unsigned n_resident = 0;
> + unsigned n_share = 0;
> + unsigned n_text = 0;
> + unsigned n_lib = 0;
> + unsigned n_data = 0;
> + unsigned n_dt = 0;
> + int i = 0;
> +
> + f = fopen ("/proc/self/statm", "r");
Suggest:
TEST_VERIFY_EXIT (f != NULL);
fscanf (f,"%u %u %u %u %u %u %u",
&n_rss,&n_resident,&n_share,&n_text,&n_lib,&n_data,&n_dt);
printf ("n_rss=%d\n", n_rss);
printf ("n_resident=%d\n", n_resident);
fclose (f);
~~~
> + if (f)
> + {
> + fscanf (f,"%u %u %u %u %u %u %u",
> + &n_rss,&n_resident,&n_share,&n_text,&n_lib,&n_data,&n_dt);
> + printf ("n_rss=%d\n", n_rss);
> + printf ("n_resident=%d\n", n_resident);
> + fclose (f);
> + }
> + else
> + return -1;
~~~
> +
> + void **mem1 = (void**) malloc (sizeof (void*) * MEM_SIZE);
> + void **mem2 = (void**) malloc (sizeof (void*) * MEM_SIZE);
> +
> + for (i = 0; i < MEM_SIZE; i++)
> + {
> + mem1[i] = malloc (BLK_SIZE);
> + if (mem1[i] == NULL)
> + {
> + printf ("malloc(BLK_SIZE) failed.\n");
> + return -1;
> + }
> + memset (mem1[i], 0xa, BLK_SIZE);
> + }
> +
> + /* Place a fence in front of the program break to make the main arena
> + discoutinuous. Make sure we do not cover any region that have been
> + accquire by sbrk. */
Suggest:
/* Place a private anonymous mapping after the process break region to
force the creation of a discontiguous main arena (a main arena with
a hole in the middle). This operation must be done with care to
ensure that the mapping does not cover any regions that have already
been acquired by sbrk. */
> + long page_sz = sysconf (_SC_PAGESIZE);
> + void *fence_addr = mem1[MEM_SIZE - 1] + TOP_PAD_SIZE + BLK_SIZE + page_sz;
> + fence_addr = (void *)((long)fence_addr & ~(page_sz - 1));
I believe you can include 'libc-pointer-arith.h' and use PTR_ALIGN_UP() for this.
> +
> + void *tt = mmap (fence_addr, page_sz, PROT_READ | PROT_WRITE,
> + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
> + if (tt == MAP_FAILED || tt != fence_addr)
> + {
> + printf ("mmap(fence_addr, page_sz, PROT_READ | PROT_WRITE, \
> + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) failed.\n");
> + return -1;
All of this can become:
FAIL_EXIT1 ("...", ..., ..., ...);
See support/check.h.
You can use the following to access the routines:
#include <support/check.h>
#include <support/support.h>
(at the top with your other includes).
> + }
> +
Needs some comments explaining what is is being attempted here.
> + for (i = 0; i < MEM_SIZE; i++)
> + {
> + mem2[i] = malloc (BLK_SIZE);
> + if (mem2[i] == NULL)
> + {
> + printf ("malloc(BLK_SIZE) failed.\n");
> + return -1;
> + }
Suggest just using `TEST_VERIFY_EXIT (mem2[i] != NULL);`
> + memset (mem2[i], 0xb, BLK_SIZE);
> + }
> +
> + for (i = 0; i < MEM_SIZE; i++)
> + {
> + free (mem1[i]);
> + mem1[i] = NULL;
> + }
> + free (mem1);
> +
> + for (i = 0; i < MEM_SIZE; i++)
> + {
> + free (mem2[i]);
> + mem2[i] = NULL;
> + }
> + free (mem2);
> +
> + f = fopen ("/proc/self/statm", "r");
TEST_VERIFY_EXIT (f != NULL);
> + if (f)
> + {
> + fscanf (f,"%u %u %u %u %u %u %u",
> + &n_rss,&n_resident,&n_share,&n_text,&n_lib,&n_data,&n_dt);
> + printf ("### n_rss=%d\n", n_rss);
> + printf ("### n_resident=%d\n", n_resident);
> + fclose (f);
> + }
> + else
> + return -1;
If you use TEST_VERIFY_EXIT as noted above then this whole
block of code just comes out of the 'if' and is called
unconditionally.
> +
> + if (n_resident > 1000)
> + return -1;
Needs a comment explaining why this is a failure.
TEST_VERIFY_EXIT (n_resident > 1000);
I do not suggest doing it this way.
I suggest sampling n_resident at the start *before*
any allocations happen in the test, then again at the
end, and looking for a difference that is small.
Checking the absolute value of n_resident will need
adjustment for all the other architectures that glibc
supports. While the difference in memory usage will
likely be constant for all architectures.
> +
> + return 0;
> +}
> +
> +#define TEST_FUNCTION do_test ()
> +#include "../test-skeleton.c"
As Joseph pointed out this should use:
#include <support/test-driver.c>
> +
>
>
>
>
>
> ------------------原始邮件------------------
> 发件人：JosephMyers <joseph@codesourcery.com>
> 收件人：贺洪军10036572;
> 抄送人：libc-alpha@sourceware.org <libc-alpha@sourceware.org>;
> 日 期 ：2018年11月30日 01:24
> 主 题 ：Re: Bug 15321 - malloc/free can't give the memory back to kernel when main_arena is discontinous
> On Thu, 29 Nov 2018, He.Hongjun@zte.com.cn wrote:
>
>> Hello, I have fixed the Bug 15321.
>> patch on glibc-2.28
>
> Do you have an FSF copyright assignment? (Are you covered by the one for
> "Chengdu Zhongxing Software Company Limited (ZTE)" dated 23 August 2018?)
>
>> diff --git a/malloc/tst-discontinuous-main-arena.c b/malloc/tst-discontinuous-main-arena.c
>> old mode 100644
>> new mode 100755
>> index e69de29..3f6f0e7
>> --- a/malloc/tst-discontinuous-main-arena.c
>> +++ b/malloc/tst-discontinuous-main-arena.c
>> @@ -0,0 +1,128 @@
>> +/* Ensure that main arena of discontinuity can normal free memory.
>> +
>> + The GNU C Library is free software; you can redistribute it and/or
>
> Missing copyright notice, before the license notice.
>
>> +#define TEST_FUNCTION do_test ()
>> +#include "../test-skeleton.c"
>
> New tests should use <support/test-driver.c>, not the old-style
> test-skeleton.c.
>
> --
> Joseph S. Myers
> joseph@codesourcery.com
>
Hello, this is the new patch
------------------原始邮件------------------
发件人：CarlosO'Donell <carlos@redhat.com>
收件人：贺洪军10036572;joseph@codesourcery.com <joseph@codesourcery.com>;
抄送人：libc-alpha@sourceware.org <libc-alpha@sourceware.org>;
日 期 ：2018年11月30日 11:05
主 题 ：Re: 答复: Re: Bug 15321 - malloc/free can't give the memory back to kernel when main_arena is discontinous
On 11/29/18 8:08 PM, He.Hongjun@zte.com.cn wrote:
> yes, covered by the one for "Chengdu Zhongxing Software Company Limited (ZTE)" dated 23 August 2018.
>
> I have added the copyright notice in the tst-discontinuous-main-arena.c
I look forward to a v2.
(1) Include a detailed description of your changes.
At a high level can you describe what the patch does and
what it fixes? Such a description is required for the
git commit message and is an important part of establishing
the intentions of your technical change. A reviewer, like
myself, can then review that the code matches your high-level
itent (or design).
(2) Please attach the patch to the next email.
While the contribution checklist says there is a strong preference
to inline the patch in our email, this sometimes breaks the patch
because MUAs may convert tabs and spaces or wrap lines. For v2,
I suggest you commit your code to your local git repo, and then
send us `git format-patch HEAD~1` which will show us everything
you *would* have committed when you push the patch. This lets me
review everything including the commit message.
> 2018-11-28 Hehongjun <He.Hongjun@zte.com.cn>
>
> [BZ #15321]
> * malloc/Makefile: add tst-discontinuous-main-arena.
> * malloc/arena.c (heap_trim): add main arean
> * malloc/malloc.c: modify discontinuous main arena
> with sysmalloc, modify discontinuous main arena link heap.
> with _int_free, free memory on discontinuous main arena link heap.
> * malloc/tst-discontinuous-main-arena: New test.
>
> diff --git a/malloc/Makefile b/malloc/Makefile
> index 7d54bad..9d60ab1 100644
> --- a/malloc/Makefile
> +++ b/malloc/Makefile
> @@ -38,6 +38,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
> tst-malloc_info \
> tst-malloc-too-large \
> tst-malloc-stats-cancellation \
> + tst-discontinuous-main-arena \
I think this is the wrong place to put this test, see notes bleow.
>
> tests-static := \
> tst-interpose-static-nothread \
> diff --git a/malloc/arena.c b/malloc/arena.c
> index 497ae47..343ef13 100755
> --- a/malloc/arena.c
> +++ b/malloc/arena.c
> @@ -634,6 +634,45 @@ heap_trim (heap_info *heap, size_t pad)
> /*check_chunk(ar_ptr, top_chunk);*/
> }
>
> + if (ar_ptr == &main_arena && heap->prev == NULL)
> + {
> + char *old_top;
> + old_top = (char *) (heap + 1);
> + p = (mchunkptr) (old_top + sizeof (unsigned long));
> +
> + misalign = (unsigned long) chunk2mem (p) & MALLOC_ALIGN_MASK;
> + if (misalign > 0)
> + p = ((char *) p) + MALLOC_ALIGNMENT - misalign;
> +
> + if (top_chunk == (mchunkptr) p)
> + {
> + p = (mchunkptr) (*(unsigned long *) old_top);
> + p = prev_chunk (p);
> + new_size = chunksize (p) + MINSIZE;
> +
> + if (!prev_inuse (p))
> + new_size += prev_size (p);
> +
> + if (new_size >= pad + MINSIZE + pagesz)
> + {
> + ar_ptr->system_mem -= heap->size;
> + delete_heap (heap);
> + if (!prev_inuse (p)) { /* consolidate backward */
> + p = prev_chunk (p);
> + unlink (ar_ptr, p, bck, fwd);
> + }
> +
> + top (ar_ptr) = top_chunk = (char *) p - 2 * SIZE_SZ;
> + set_head (top_chunk, new_size | PREV_INUSE);
> +
> + set_contiguous (ar_ptr);
> + if ((unsigned long)(chunksize (ar_ptr->top)) >= (unsigned long)mp_.trim_threshold)
> + systrim (mp_.trim_threshold, ar_ptr);
> + return 0;
> + }
> + }
> + }
> +
I need to spend some time reviewing this and matching it
with your intent. So I'll wait for v2 to review this.
> /* Uses similar logic for per-thread arenas as the main arena with systrim
> and _int_free by preserving the top pad and rounding down to the nearest
> page. */
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index e247c77..ad53ef7 100755
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -2388,7 +2388,7 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
> assert ((unsigned long) (old_size) < (unsigned long) (nb + MINSIZE));
>
>
> - if (av != &main_arena)
> + if ((av != &main_arena) || (av == &main_arena && !contiguous (av)))
> {
> heap_info *old_heap, *heap;
> size_t old_heap_size;
> @@ -2438,8 +2438,6 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
> goto try_mmap;
> }
> else /* av == main_arena */
> -
> -
Please avoid any white space changes which are not related to the
change you are making.
Please feel free to submit another patch to fix this independently
of the change.
> { /* Request enough space for nb + pad + overhead */
> size = nb + mp_.top_pad + MINSIZE;
>
> @@ -2491,35 +2489,62 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
> and threshold limits, since the space will not be used as a
> segregated mmap region.
> */
> -
> - /* Cannot merge with old top, so add its size back in */
> - if (contiguous (av))
> - size = ALIGN_UP (size + old_size, pagesize);
> -
> - /* If we are relying on mmap as backup, then use larger units */
> - if ((unsigned long) (size) < (unsigned long) (MMAP_AS_MORECORE_SIZE))
> - size = MMAP_AS_MORECORE_SIZE;
> -
> - /* Don't try if size wraps around 0 */
> - if ((unsigned long) (size) > (unsigned long) (nb))
> - {
> - char *mbrk = (char *) (MMAP (0, size, PROT_READ | PROT_WRITE, 0));
> -
> - if (mbrk != MAP_FAILED)
> + heap_info *heap;
> + long misalign;
> + char *ptr;
> + heap = new_heap (nb + (MINSIZE + sizeof (*heap) + MALLOC_ALIGNMENT), mp_.top_pad);
> + if (!heap)
> + {
> + if (!tried_mmap)
> + goto try_mmap;
> + else
> {
> - /* We do not need, and cannot use, another sbrk call to find end */
> - brk = mbrk;
> - snd_brk = brk + size;
> + __set_errno (ENOMEM);
> + return 0;
> + }
> + }
> +
> + heap->ar_ptr = av;
> + heap->prev = NULL;
> + av->system_mem += heap->size;
> +
> + ptr = (char *) (heap + 1);
> + ptr += sizeof (unsigned long);
> + misalign = (unsigned long) chunk2mem (ptr) & MALLOC_ALIGN_MASK;
> + if (misalign > 0)
> + ptr += MALLOC_ALIGNMENT - misalign;
> + /* Set up the new top. */
> + top (av) = ptr;
> + set_head (top (av), (((char *) heap + heap->size) - ptr) | PREV_INUSE);
>
> - /*
> - Record that we no longer have a contiguous sbrk region.
> - After the first time mmap is used as backup, we do not
> - ever rely on contiguous space since this could incorrectly
> - bridge regions.
> - */
> - set_noncontiguous (av);
> - }
> + /* Setup fencepost and free the old top chunk with a multiple of
> + MALLOC_ALIGNMENT in size. */
> + /* The fencepost takes at least MINSIZE bytes, because it might
> + become the top chunk again later. Note that a footer is set
> + up, too, although the chunk is marked in use. */
> + old_size = (old_size - MINSIZE) & ~MALLOC_ALIGN_MASK;
> + set_head (chunk_at_offset (old_top, old_size + 2 * SIZE_SZ), 0 | PREV_INUSE);
> + *(unsigned long *)((heap + 1)) = chunk_at_offset (old_top, old_size + 2 * SIZE_SZ);
> + if (old_size >= MINSIZE)
> + {
> + set_head (chunk_at_offset (old_top, old_size), (2 * SIZE_SZ) | PREV_INUSE);
> + set_foot (chunk_at_offset (old_top, old_size), (2 * SIZE_SZ));
> + set_head (old_top, old_size | PREV_INUSE);
> + _int_free (av, old_top, 1);
> + }
> + else
> + {
> + set_head (old_top, (old_size + 2 * SIZE_SZ) | PREV_INUSE);
> + set_foot (old_top, (old_size + 2 * SIZE_SZ));
> }
> +
> + /*
> + Record that we no longer have a contiguous sbrk region.
> + After the first time mmap is used as backup, we do not
> + ever rely on contiguous space since this could incorrectly
> + bridge regions.
> + */
> + set_noncontiguous (av);
Again, this needs more review and I'll try to get to that in your v2.
> }
>
> if (brk != (char *) (MORECORE_FAILURE))
> @@ -4347,7 +4372,7 @@ _int_free (mstate av, mchunkptr p, int have_lock)
> if (atomic_load_relaxed (&av->have_fastchunks))
> malloc_consolidate(av);
>
> - if (av == &main_arena) {
> + if ((av == &main_arena ) && contiguous (av)) {
> #ifndef MORECORE_CANNOT_TRIM
> if ((unsigned long)(chunksize(av->top)) >=
> (unsigned long)(mp_.trim_threshold))
> diff --git a/malloc/tst-discontinuous-main-arena.c b/malloc/tst-discontinuous-main-arena.c
> old mode 100644
> new mode 100755
> index e69de29..ef7249f
> --- a/malloc/tst-discontinuous-main-arena.c
> +++ b/malloc/tst-discontinuous-main-arena.c
This file is linux-specific and parses /proc/self/statm.
I suggest:
sysdeps/unix/sysv/linux/tst-discontig-main-arena.c
Add it to:
sysdeps/unix/sysv/linux/Makefile
here (around line 10):
~~~
....
ifeq ($(subdir),malloc)
CFLAGS-malloc.c += -DMORECORE_CLEARS=2
tests += tst-discontig-main-arena
endif
....
~~~
> @@ -0,0 +1,133 @@
It should look like this:
/* <One sentence description.>
<Copyright line, with 2018 only because this is a new test.>
<Rest of the license> */
We no longer use 'Contributed by' lines, we rely on ChangeLogs and
git commit messages to provide attribution.
I suggest:
/* Test that a discontinuous main arena can free through the gap.
Copyright (C) 2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
> +/* Copyright (C) 1999-2018 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> + Contributed by He.Hongjun@zte.com.cn, 2018.
> +
> + Ensure that main arena of discontinuity can normal free memory.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public License as
> + published by the Free Software Foundation; either version 2.1 of the
> + License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; see the file COPYING.LIB. If
> + not, see <http://www.gnu.org/licenses/>. */
> +
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/mman.h>
> +
> +#define MEM_SIZE 1024*128
This isn't a size, but rather a count? Should we call it BLK_COUNT?
> +#define BLK_SIZE 1024
> +#define TOP_PAD_SIZE 1024 * 128
> +
Test needs a block comment at the top explaining in detail the intent of the test.
> +static int
> +do_test (void)
> +{
> + /* Get the peak physical memory usage. */
> + FILE *f;
> + unsigned n_rss = 0;
> + unsigned n_resident = 0;
> + unsigned n_share = 0;
> + unsigned n_text = 0;
> + unsigned n_lib = 0;
> + unsigned n_data = 0;
> + unsigned n_dt = 0;
> + int i = 0;
> +
> + f = fopen ("/proc/self/statm", "r");
Suggest:
TEST_VERIFY_EXIT (f != NULL);
fscanf (f,"%u %u %u %u %u %u %u",
&n_rss,&n_resident,&n_share,&n_text,&n_lib,&n_data,&n_dt);
printf ("n_rss=%d\n", n_rss);
printf ("n_resident=%d\n", n_resident);
fclose (f);
~~~
> + if (f)
> + {
> + fscanf (f,"%u %u %u %u %u %u %u",
> + &n_rss,&n_resident,&n_share,&n_text,&n_lib,&n_data,&n_dt);
> + printf ("n_rss=%d\n", n_rss);
> + printf ("n_resident=%d\n", n_resident);
> + fclose (f);
> + }
> + else
> + return -1;
~~~
> +
> + void **mem1 = (void**) malloc (sizeof (void*) * MEM_SIZE);
> + void **mem2 = (void**) malloc (sizeof (void*) * MEM_SIZE);
> +
> + for (i = 0; i < MEM_SIZE; i++)
> + {
> + mem1[i] = malloc (BLK_SIZE);
> + if (mem1[i] == NULL)
> + {
> + printf ("malloc(BLK_SIZE) failed.\n");
> + return -1;
> + }
> + memset (mem1[i], 0xa, BLK_SIZE);
> + }
> +
> + /* Place a fence in front of the program break to make the main arena
> + discoutinuous. Make sure we do not cover any region that have been
> + accquire by sbrk. */
Suggest:
/* Place a private anonymous mapping after the process break region to
force the creation of a discontiguous main arena (a main arena with
a hole in the middle). This operation must be done with care to
ensure that the mapping does not cover any regions that have already
been acquired by sbrk. */
> + long page_sz = sysconf (_SC_PAGESIZE);
> + void *fence_addr = mem1[MEM_SIZE - 1] + TOP_PAD_SIZE + BLK_SIZE + page_sz;
> + fence_addr = (void *)((long)fence_addr & ~(page_sz - 1));
I believe you can include 'libc-pointer-arith.h' and use PTR_ALIGN_UP() for this.
> +
> + void *tt = mmap (fence_addr, page_sz, PROT_READ | PROT_WRITE,
> + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
> + if (tt == MAP_FAILED || tt != fence_addr)
> + {
> + printf ("mmap(fence_addr, page_sz, PROT_READ | PROT_WRITE, \
> + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) failed..\n");
> + return -1;
All of this can become:
FAIL_EXIT1 ("...", ..., ..., ...);
See support/check.h.
You can use the following to access the routines:
#include <support/check.h>
#include <support/support.h>
(at the top with your other includes).
> + }
> +
Needs some comments explaining what is is being attempted here.
> + for (i = 0; i < MEM_SIZE; i++)
> + {
> + mem2[i] = malloc (BLK_SIZE);
> + if (mem2[i] == NULL)
> + {
> + printf ("malloc(BLK_SIZE) failed.\n");
> + return -1;
> + }
Suggest just using `TEST_VERIFY_EXIT (mem2[i] != NULL);`
> + memset (mem2[i], 0xb, BLK_SIZE);
> + }
> +
> + for (i = 0; i < MEM_SIZE; i++)
> + {
> + free (mem1[i]);
> + mem1[i] = NULL;
> + }
> + free (mem1);
> +
> + for (i = 0; i < MEM_SIZE; i++)
> + {
> + free (mem2[i]);
> + mem2[i] = NULL;
> + }
> + free (mem2);
> +
> + f = fopen ("/proc/self/statm", "r");
TEST_VERIFY_EXIT (f != NULL);
> + if (f)
> + {
> + fscanf (f,"%u %u %u %u %u %u %u",
> + &n_rss,&n_resident,&n_share,&n_text,&n_lib,&n_data,&n_dt);
> + printf ("### n_rss=%d\n", n_rss);
> + printf ("### n_resident=%d\n", n_resident);
> + fclose (f);
> + }
> + else
> + return -1;
If you use TEST_VERIFY_EXIT as noted above then this whole
block of code just comes out of the 'if' and is called
unconditionally.
> +
> + if (n_resident > 1000)
> + return -1;
Needs a comment explaining why this is a failure.
TEST_VERIFY_EXIT (n_resident > 1000);
I do not suggest doing it this way.
I suggest sampling n_resident at the start *before*
any allocations happen in the test, then again at the
end, and looking for a difference that is small.
Checking the absolute value of n_resident will need
adjustment for all the other architectures that glibc
supports. While the difference in memory usage will
likely be constant for all architectures.
> +
> + return 0;
> +}
> +
> +#define TEST_FUNCTION do_test ()
> +#include "../test-skeleton.c"
As Joseph pointed out this should use:
#include <support/test-driver.c>
> +
>
>
>
>
>
> ------------------原始邮件------------------
> 发件人：JosephMyers <joseph@codesourcery.com>
> 收件人：贺洪军10036572;
> 抄送人：libc-alpha@sourceware.org <libc-alpha@sourceware.org>;
> 日 期 ：2018年11月30日 01:24
> 主 题 ：Re: Bug 15321 - malloc/free can't give the memory back to kernel when main_arena is discontinous
> On Thu, 29 Nov 2018, He.Hongjun@zte.com.cn wrote:
>
>> Hello, I have fixed the Bug 15321.
>> patch on glibc-2.28
>
> Do you have an FSF copyright assignment? (Are you covered by the one for
> "Chengdu Zhongxing Software Company Limited (ZTE)" dated 23 August 2018?)
>
>> diff --git a/malloc/tst-discontinuous-main-arena.c b/malloc/tst-discontinuous-main-arena.c
>> old mode 100644
>> new mode 100755
>> index e69de29..3f6f0e7
>> --- a/malloc/tst-discontinuous-main-arena.c
>> +++ b/malloc/tst-discontinuous-main-arena.c
>> @@ -0,0 +1,128 @@
>> +/* Ensure that main arena of discontinuity can normal free memory.
>> +
>> + The GNU C Library is free software; you can redistribute it and/or
>
> Missing copyright notice, before the license notice.
>
>> +#define TEST_FUNCTION do_test ()
>> +#include "../test-skeleton.c"
>
> New tests should use <support/test-driver.c>, not the old-style
> test-skeleton.c.
>
> --
> Joseph S. Myers
> joseph@codesourcery.com
>
--
Cheers,
Carlos.
On Fri, 30 Nov 2018, He.Hongjun@zte.com.cn wrote:
> Hello, this is the new patch
This appears not to have addressed most of the comments that Carlos and I
had. Please review our comments carefully and make sure you send the
correct version of the patch that addresses *all* those comments, or state
explicitly if you disagree with a particular comment.
@@ -38,6 +38,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
tst-malloc_info \
tst-malloc-too-large \
tst-malloc-stats-cancellation \
+ tst-discontinuous-main-arena \
tests-static := \
tst-interpose-static-nothread \
@@ -634,6 +634,45 @@ heap_trim (heap_info *heap, size_t pad)
/*check_chunk(ar_ptr, top_chunk);*/
}
+ if (ar_ptr == &main_arena && heap->prev == NULL)
+ {
+ char *old_top;
+ old_top = (char *) (heap + 1);
+ p = (mchunkptr) (old_top + sizeof (unsigned long));
+
+ misalign = (unsigned long) chunk2mem (p) & MALLOC_ALIGN_MASK;
+ if (misalign > 0)
+ p = ((char *) p) + MALLOC_ALIGNMENT - misalign;
+
+ if (top_chunk == (mchunkptr) p)
+ {
+ p = (mchunkptr) (*(unsigned long *) old_top);
+ p = prev_chunk (p);
+ new_size = chunksize (p) + MINSIZE;
+
+ if (!prev_inuse (p))
+ new_size += prev_size (p);
+
+ if (new_size >= pad + MINSIZE + pagesz)
+ {
+ ar_ptr->system_mem -= heap->size;
+ delete_heap (heap);
+ if (!prev_inuse (p)) { /* consolidate backward */
+ p = prev_chunk (p);
+ unlink (ar_ptr, p, bck, fwd);
+ }
+
+ top (ar_ptr) = top_chunk = (char *) p - 2 * SIZE_SZ;
+ set_head (top_chunk, new_size | PREV_INUSE);
+
+ set_contiguous (ar_ptr);
+ if ((unsigned long)(chunksize (ar_ptr->top)) >= (unsigned long)mp_.trim_threshold)
+ systrim (mp_.trim_threshold, ar_ptr);
+ return 0;
+ }
+ }
+ }
+
/* Uses similar logic for per-thread arenas as the main arena with systrim
and _int_free by preserving the top pad and rounding down to the nearest
page. */
@@ -2388,7 +2388,7 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
assert ((unsigned long) (old_size) < (unsigned long) (nb + MINSIZE));
- if (av != &main_arena)
+ if ((av != &main_arena) || (av == &main_arena && !contiguous (av)))
{
heap_info *old_heap, *heap;
size_t old_heap_size;
@@ -2438,8 +2438,6 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
goto try_mmap;
}
else /* av == main_arena */
-
-
{ /* Request enough space for nb + pad + overhead */
size = nb + mp_.top_pad + MINSIZE;
@@ -2491,35 +2489,62 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
and threshold limits, since the space will not be used as a
segregated mmap region.
*/
-
- /* Cannot merge with old top, so add its size back in */
- if (contiguous (av))
- size = ALIGN_UP (size + old_size, pagesize);
-
- /* If we are relying on mmap as backup, then use larger units */
- if ((unsigned long) (size) < (unsigned long) (MMAP_AS_MORECORE_SIZE))
- size = MMAP_AS_MORECORE_SIZE;
-
- /* Don't try if size wraps around 0 */
- if ((unsigned long) (size) > (unsigned long) (nb))
- {
- char *mbrk = (char *) (MMAP (0, size, PROT_READ | PROT_WRITE, 0));
-
- if (mbrk != MAP_FAILED)
+ heap_info *heap;
+ long misalign;
+ char *ptr;
+ heap = new_heap (nb + (MINSIZE + sizeof (*heap) + MALLOC_ALIGNMENT), mp_.top_pad);
+ if (!heap)
+ {
+ if (!tried_mmap)
+ goto try_mmap;
+ else
{
- /* We do not need, and cannot use, another sbrk call to find end */
- brk = mbrk;
- snd_brk = brk + size;
+ __set_errno (ENOMEM);
+ return 0;
+ }
+ }
+
+ heap->ar_ptr = av;
+ heap->prev = NULL;
+ av->system_mem += heap->size;
+
+ ptr = (char *) (heap + 1);
+ ptr += sizeof (unsigned long);
+ misalign = (unsigned long) chunk2mem (ptr) & MALLOC_ALIGN_MASK;
+ if (misalign > 0)
+ ptr += MALLOC_ALIGNMENT - misalign;
+ /* Set up the new top. */
+ top (av) = ptr;
+ set_head (top (av), (((char *) heap + heap->size) - ptr) | PREV_INUSE);
- /*
- Record that we no longer have a contiguous sbrk region.
- After the first time mmap is used as backup, we do not
- ever rely on contiguous space since this could incorrectly
- bridge regions.
- */
- set_noncontiguous (av);
- }
+ /* Setup fencepost and free the old top chunk with a multiple of
+ MALLOC_ALIGNMENT in size. */
+ /* The fencepost takes at least MINSIZE bytes, because it might
+ become the top chunk again later. Note that a footer is set
+ up, too, although the chunk is marked in use. */
+ old_size = (old_size - MINSIZE) & ~MALLOC_ALIGN_MASK;
+ set_head (chunk_at_offset (old_top, old_size + 2 * SIZE_SZ), 0 | PREV_INUSE);
+ *(unsigned long *)((heap + 1)) = chunk_at_offset (old_top, old_size + 2 * SIZE_SZ);
+ if (old_size >= MINSIZE)
+ {
+ set_head (chunk_at_offset (old_top, old_size), (2 * SIZE_SZ) | PREV_INUSE);
+ set_foot (chunk_at_offset (old_top, old_size), (2 * SIZE_SZ));
+ set_head (old_top, old_size | PREV_INUSE);
+ _int_free (av, old_top, 1);
+ }
+ else
+ {
+ set_head (old_top, (old_size + 2 * SIZE_SZ) | PREV_INUSE);
+ set_foot (old_top, (old_size + 2 * SIZE_SZ));
}
+
+ /*
+ Record that we no longer have a contiguous sbrk region.
+ After the first time mmap is used as backup, we do not
+ ever rely on contiguous space since this could incorrectly
+ bridge regions.
+ */
+ set_noncontiguous (av);
}
if (brk != (char *) (MORECORE_FAILURE))
@@ -4347,7 +4372,7 @@ _int_free (mstate av, mchunkptr p, int have_lock)
if (atomic_load_relaxed (&av->have_fastchunks))
malloc_consolidate(av);
- if (av == &main_arena) {
+ if ((av == &main_arena ) && contiguous (av)) {
#ifndef MORECORE_CANNOT_TRIM
if ((unsigned long)(chunksize(av->top)) >=
(unsigned long)(mp_.trim_threshold))
old mode 100644
new mode 100755
@@ -0,0 +1,133 @@
+/* Copyright (C) 1999-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by He.Hongjun@zte.com.cn, 2018.
+
+ Ensure that main arena of discontinuity can normal free memory.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If
+ not, see <http://www.gnu.org/licenses/>. */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+#define MEM_SIZE 1024*128
+#define BLK_SIZE 1024
+#define TOP_PAD_SIZE 1024 * 128
+
+static int
+do_test (void)
+{
+ /* Get the peak physical memory usage. */
+ FILE *f;
+ unsigned n_rss = 0;
+ unsigned n_resident = 0;
+ unsigned n_share = 0;
+ unsigned n_text = 0;
+ unsigned n_lib = 0;
+ unsigned n_data = 0;
+ unsigned n_dt = 0;
+ int i = 0;
+
+ f = fopen ("/proc/self/statm", "r");
+ if (f)
+ {
+ fscanf (f,"%u %u %u %u %u %u %u",
+ &n_rss,&n_resident,&n_share,&n_text,&n_lib,&n_data,&n_dt);
+ printf ("n_rss=%d\n", n_rss);
+ printf ("n_resident=%d\n", n_resident);
+ fclose (f);
+ }
+ else
+ return -1;
+
+ void **mem1 = (void**) malloc (sizeof (void*) * MEM_SIZE);
+ void **mem2 = (void**) malloc (sizeof (void*) * MEM_SIZE);
+
+ for (i = 0; i < MEM_SIZE; i++)
+ {
+ mem1[i] = malloc (BLK_SIZE);
+ if (mem1[i] == NULL)
+ {
+ printf ("malloc(BLK_SIZE) failed.\n");
+ return -1;
+ }
+ memset (mem1[i], 0xa, BLK_SIZE);
+ }
+
+ /* Place a fence in front of the program break to make the main arena
+ discoutinuous. Make sure we do not cover any region that have been
+ accquire by sbrk. */
+ long page_sz = sysconf (_SC_PAGESIZE);
+ void *fence_addr = mem1[MEM_SIZE - 1] + TOP_PAD_SIZE + BLK_SIZE + page_sz;
+ fence_addr = (void *)((long)fence_addr & ~(page_sz - 1));
+
+ void *tt = mmap (fence_addr, page_sz, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+ if (tt == MAP_FAILED || tt != fence_addr)
+ {
+ printf ("mmap(fence_addr, page_sz, PROT_READ | PROT_WRITE, \
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) failed.\n");
+ return -1;
+ }
+
+ for (i = 0; i < MEM_SIZE; i++)
+ {
+ mem2[i] = malloc (BLK_SIZE);
+ if (mem2[i] == NULL)
+ {
+ printf ("malloc(BLK_SIZE) failed.\n");
+ return -1;
+ }
+ memset (mem2[i], 0xb, BLK_SIZE);
+ }
+
+ for (i = 0; i < MEM_SIZE; i++)
+ {
+ free (mem1[i]);
+ mem1[i] = NULL;
+ }
+ free (mem1);
+
+ for (i = 0; i < MEM_SIZE; i++)
+ {
+ free (mem2[i]);
+ mem2[i] = NULL;
+ }
+ free (mem2);
+
+ f = fopen ("/proc/self/statm", "r");
+ if (f)
+ {
+ fscanf (f,"%u %u %u %u %u %u %u",
+ &n_rss,&n_resident,&n_share,&n_text,&n_lib,&n_data,&n_dt);
+ printf ("### n_rss=%d\n", n_rss);
+ printf ("### n_resident=%d\n", n_resident);
+ fclose (f);
+ }
+ else
+ return -1;
+
+ if (n_resident > 1000)
+ return -1;
+
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+