android_kernel_xiaomi_sm8350/mm
KOSAKI Motohiro 659ace584e mmap: don't return ENOMEM when mapcount is temporarily exceeded in munmap()
On ia64, the following test program exit abnormally, because glibc thread
library called abort().

 ========================================================
 (gdb) bt
 #0  0xa000000000010620 in __kernel_syscall_via_break ()
 #1  0x20000000003208e0 in raise () from /lib/libc.so.6.1
 #2  0x2000000000324090 in abort () from /lib/libc.so.6.1
 #3  0x200000000027c3e0 in __deallocate_stack () from /lib/libpthread.so.0
 #4  0x200000000027f7c0 in start_thread () from /lib/libpthread.so.0
 #5  0x200000000047ef60 in __clone2 () from /lib/libc.so.6.1
 ========================================================

The fact is, glibc call munmap() when thread exitng time for freeing
stack, and it assume munlock() never fail.  However, munmap() often make
vma splitting and it with many mapcount make -ENOMEM.

Oh well, that's crazy, because stack unmapping never increase mapcount.
The maxcount exceeding is only temporary.  internal temporary exceeding
shouldn't make ENOMEM.

This patch does it.

 test_max_mapcount.c
 ==================================================================
  #include<stdio.h>
  #include<stdlib.h>
  #include<string.h>
  #include<pthread.h>
  #include<errno.h>
  #include<unistd.h>

  #define THREAD_NUM 30000
  #define MAL_SIZE (8*1024*1024)

 void *wait_thread(void *args)
 {
 	void *addr;

 	addr = malloc(MAL_SIZE);
 	sleep(10);

 	return NULL;
 }

 void *wait_thread2(void *args)
 {
 	sleep(60);

 	return NULL;
 }

 int main(int argc, char *argv[])
 {
 	int i;
 	pthread_t thread[THREAD_NUM], th;
 	int ret, count = 0;
 	pthread_attr_t attr;

 	ret = pthread_attr_init(&attr);
 	if(ret) {
 		perror("pthread_attr_init");
 	}

 	ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	if(ret) {
 		perror("pthread_attr_setdetachstate");
 	}

 	for (i = 0; i < THREAD_NUM; i++) {
 		ret = pthread_create(&th, &attr, wait_thread, NULL);
 		if(ret) {
 			fprintf(stderr, "[%d] ", count);
 			perror("pthread_create");
 		} else {
 			printf("[%d] create OK.\n", count);
 		}
 		count++;

 		ret = pthread_create(&thread[i], &attr, wait_thread2, NULL);
 		if(ret) {
 			fprintf(stderr, "[%d] ", count);
 			perror("pthread_create");
 		} else {
 			printf("[%d] create OK.\n", count);
 		}
 		count++;
 	}

 	sleep(3600);
 	return 0;
 }
 ==================================================================

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: 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>
2009-12-15 08:53:11 -08:00
..
backing-dev.c flusher: Fix PF_FROZEN race 2009-12-03 13:49:43 +01:00
bootmem.c bootmem: Add free_bootmem_late() 2009-11-10 12:31:43 +01:00
bounce.c
debug-pagealloc.c
dmapool.c dmapools: protect page_list walk in show_pools() 2009-06-30 18:56:00 -07:00
fadvise.c
failslab.c
filemap_xip.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
filemap.c kill wait_on_page_writeback_range 2009-12-10 15:02:50 +01:00
fremap.c
highmem.c highmem: Fix debug_kmap_atomic() to also handle KM_IRQ_PTE, KM_NMI, and KM_NMI_PTE 2009-11-10 04:15:47 +01:00
hugetlb.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
hwpoison-inject.c HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs 2009-09-16 11:50:17 +02:00
init-mm.c
internal.h mm: move highest_memmap_pfn 2009-09-22 07:17:41 -07:00
Kconfig mm: allow memory hotplug and hibernation in the same kernel 2009-11-17 17:40:33 -08:00
Kconfig.debug trivial: improve help text for mm debug config options 2009-09-21 15:14:57 +02:00
kmemcheck.c
kmemleak-test.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
kmemleak.c tree-wide: fix typos "aquire" -> "acquire", "cumsumed" -> "consumed" 2009-11-09 09:40:57 +01:00
ksm.c ksm: cond_resched in unstable tree 2009-11-09 09:55:44 -08:00
maccess.c
madvise.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-09-24 07:53:22 -07:00
Makefile percpu: kill legacy percpu allocator 2009-10-02 13:29:29 +09:00
memcontrol.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
memory_hotplug.c mm: allow memory hotplug and hibernation in the same kernel 2009-11-17 17:40:33 -08:00
memory-failure.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
memory.c Merge branch 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-10-29 08:20:00 -07:00
mempolicy.c do_mbind(): fix memory leak 2009-10-29 07:39:29 -07:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c mm: Adjust do_pages_stat() so gcc can see copy_from_user() is safe 2009-12-11 15:27:47 -08:00
mincore.c
mlock.c mm: m(un)lock avoid ZERO_PAGE 2009-09-22 07:17:40 -07:00
mm_init.c
mmap.c mmap: don't return ENOMEM when mapcount is temporarily exceeded in munmap() 2009-12-15 08:53:11 -08:00
mmu_context.c mm: reduce atomic use on use_mm fast path 2009-09-22 07:17:42 -07:00
mmu_notifier.c ksm: add mmu_notifier set_pte_at_notify() 2009-09-22 07:17:31 -07:00
mmzone.c
mprotect.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
mremap.c Take arch_mmap_check() into get_unmapped_area() 2009-12-11 06:44:58 -05:00
msync.c
nommu.c NOMMU: Don't pass NULL pointers to fput() in do_mmap_pgoff() 2009-10-31 12:11:37 -07:00
oom_kill.c oom: dump stack and VM state when oom killer panics 2009-12-15 08:53:10 -08:00
page_alloc.c tracing: Fix kmem event exports 2009-11-26 13:17:43 +01:00
page_cgroup.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
page_io.c
page_isolation.c
page-writeback.c writeback: remove unused nonblocking and congestion checks 2009-12-03 13:54:25 +01:00
pagewalk.c
percpu.c Merge branch 'for-linus' into for-next 2009-12-08 10:02:12 +09:00
prio_tree.c
quicklist.c cpumask: use new-style cpumask ops in mm/quicklist. 2009-09-24 09:34:52 +09:30
readahead.c
rmap.c mm/rmap.c: fix comment 2009-10-01 16:11:12 -07:00
shmem_acl.c shmfs: use 'check_acl' instead of 'permission' 2009-09-08 11:08:46 -07:00
shmem.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
slab.c Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-14 10:13:22 -08:00
slob.c slab: remove duplicate kmem_cache_init_late() declarations 2009-08-06 11:36:25 +03:00
slub.c Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-14 10:13:22 -08:00
sparse-vmemmap.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
sparse.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
swap_state.c mm: add_to_swap_cache() does not return -EEXIST 2009-09-22 07:17:35 -07:00
swap.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
swapfile.c mm: remove incorrect swap_count() from try_to_unuse() 2009-11-02 09:44:41 -08:00
thrash.c
truncate.c mm: fix comments for invalidate_inode_pages2() 2009-12-04 15:39:48 +01:00
util.c fix a struct file leak in do_mmap_pgoff() 2009-12-11 06:44:57 -05:00
vmalloc.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-12-14 09:58:24 -08:00
vmscan.c vmscan: order evictable rescue in LRU putback 2009-10-29 07:39:30 -07:00
vmstat.c percpu: make percpu symbols under kernel/ and mm/ unique 2009-10-29 22:34:13 +09:00