The patch titled
coredump: move mm->core_waiters into struct core_state
has been removed from the -mm tree. Its filename was
coredump-move-mm-core_waiters-into-struct-core_state.patch
This patch was dropped because an updated version will be merged
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: coredump: move mm->core_waiters into struct core_state
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Move mm->core_waiters into "struct core_state" allocated on stack. This
shrinks mm_struct a little bit and allows further changes.
This patch mostly does s/core_waiters/core_state. The only essential
change is that coredump_wait() must clear mm->core_state before return.
The coredump_wait()'s path is uglified and .text grows by 30 bytes, this
is fixed by the next patch.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 21 +++++++++++----------
include/linux/mm_types.h | 2 +-
kernel/exit.c | 8 ++++----
kernel/fork.c | 2 +-
4 files changed, 17 insertions(+), 16 deletions(-)
diff -puN fs/exec.c~coredump-move-mm-core_waiters-into-struct-core_state fs/exec.c
--- a/fs/exec.c~coredump-move-mm-core_waiters-into-struct-core_state
+++ a/fs/exec.c
@@ -724,12 +724,10 @@ static int exec_mmap(struct mm_struct *m
* Make sure that if there is a core dump in progress
* for the old mm, we get out and die instead of going
* through with the exec. We must hold mmap_sem around
- * checking core_waiters and changing tsk->mm. The
- * core-inducing thread will increment core_waiters for
- * each thread whose ->mm == old_mm.
+ * checking core_state and changing tsk->mm.
*/
down_read(&old_mm->mmap_sem);
- if (unlikely(old_mm->core_waiters)) {
+ if (unlikely(old_mm->core_state)) {
up_read(&old_mm->mmap_sem);
return -EINTR;
}
@@ -1516,7 +1514,7 @@ static void zap_process(struct task_stru
t = start;
do {
if (t != current && t->mm) {
- t->mm->core_waiters++;
+ t->mm->core_state->nr_threads++;
sigaddset(&t->pending.signal, SIGKILL);
signal_wake_up(t, 1);
}
@@ -1540,11 +1538,11 @@ static inline int zap_threads(struct tas
if (err)
return err;
- if (atomic_read(&mm->mm_users) == mm->core_waiters + 1)
+ if (atomic_read(&mm->mm_users) == mm->core_state->nr_threads + 1)
goto done;
/*
* We should find and kill all tasks which use this mm, and we should
- * count them correctly into mm->core_waiters. We don't take tasklist
+ * count them correctly into ->nr_threads. We don't take tasklist
* lock, but this is safe wrt:
*
* fork:
@@ -1592,7 +1590,7 @@ static inline int zap_threads(struct tas
}
rcu_read_unlock();
done:
- return mm->core_waiters;
+ return mm->core_state->nr_threads;
}
static int coredump_wait(int exit_code)
@@ -1605,9 +1603,12 @@ static int coredump_wait(int exit_code)
init_completion(&mm->core_done);
init_completion(&core_state.startup);
+ core_state.nr_threads = 0;
mm->core_state = &core_state;
core_waiters = zap_threads(tsk, mm, exit_code);
+ if (core_waiters < 0)
+ mm->core_state = NULL;
up_write(&mm->mmap_sem);
if (unlikely(core_waiters < 0))
@@ -1625,8 +1626,8 @@ static int coredump_wait(int exit_code)
if (core_waiters)
wait_for_completion(&core_state.startup);
+ mm->core_state = NULL;
fail:
- BUG_ON(mm->core_waiters);
return core_waiters;
}
@@ -1704,7 +1705,7 @@ int do_coredump(long signr, int exit_cod
/*
* If another thread got here first, or we are not dumpable, bail out.
*/
- if (mm->core_waiters || !get_dumpable(mm)) {
+ if (mm->core_state || !get_dumpable(mm)) {
up_write(&mm->mmap_sem);
goto fail;
}
diff -puN include/linux/mm_types.h~coredump-move-mm-core_waiters-into-struct-core_state include/linux/mm_types.h
--- a/include/linux/mm_types.h~coredump-move-mm-core_waiters-into-struct-core_state
+++ a/include/linux/mm_types.h
@@ -160,6 +160,7 @@ struct vm_area_struct {
};
struct core_state {
+ int nr_threads;
struct completion startup;
};
@@ -179,7 +180,6 @@ struct mm_struct {
atomic_t mm_users; /* How many users with user space? */
atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
int map_count; /* number of VMAs */
- int core_waiters;
struct rw_semaphore mmap_sem;
spinlock_t page_table_lock; /* Protects page tables and some counters */
diff -puN kernel/exit.c~coredump-move-mm-core_waiters-into-struct-core_state kernel/exit.c
--- a/kernel/exit.c~coredump-move-mm-core_waiters-into-struct-core_state
+++ a/kernel/exit.c
@@ -662,16 +662,16 @@ static void exit_mm(struct task_struct *
return;
/*
* Serialize with any possible pending coredump.
- * We must hold mmap_sem around checking core_waiters
+ * We must hold mmap_sem around checking core_state
* and clearing tsk->mm. The core-inducing thread
- * will increment core_waiters for each thread in the
+ * will increment ->nr_threads for each thread in the
* group with ->mm != NULL.
*/
down_read(&mm->mmap_sem);
- if (mm->core_waiters) {
+ if (mm->core_state) {
up_read(&mm->mmap_sem);
down_write(&mm->mmap_sem);
- if (!--mm->core_waiters)
+ if (!--mm->core_state->nr_threads)
complete(&mm->core_state->startup);
up_write(&mm->mmap_sem);
diff -puN kernel/fork.c~coredump-move-mm-core_waiters-into-struct-core_state kernel/fork.c
--- a/kernel/fork.c~coredump-move-mm-core_waiters-into-struct-core_state
+++ a/kernel/fork.c
@@ -406,7 +406,7 @@ static struct mm_struct * mm_init(struct
INIT_LIST_HEAD(&mm->mmlist);
mm->flags = (current->mm) ? current->mm->flags
: MMF_DUMP_FILTER_DEFAULT;
- mm->core_waiters = 0;
+ mm->core_state = NULL;
mm->nr_ptes = 0;
set_mm_counter(mm, file_rss, 0);
set_mm_counter(mm, anon_rss, 0);
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
get_user_pages-fix-possible-page-leak-on-oom.patch
posix-timers-timer_delete-remove-the-bogus-it_process-=-null-check.patch
posix-timers-release_posix_timer-kill-the-bogus-put_task_struct-it_process.patch
signals-collect_signal-remove-the-unneeded-sigismember-check.patch
signals-collect_signal-simplify-the-still_pending-logic.patch
signals-change-collect_signal-to-return-void.patch
__exit_signal-dont-take-rcu-lock.patch
signals-dequeue_signal-dont-check-signal_group_exit-when-setting-signal_stop_dequeued.patch
signals-do_signal_stop-kill-the-signal_unkillable-check.patch
coredump-zap_threads-comments-use-while_each_thread.patch
signals-make-siginfo_t-si_utime-si_sstime-report-times-in-user_hz-not-hz.patch
kernel-signalc-change-vars-pid-and-tgid-types-to-pid_t.patch
include-asm-ptraceh-userspace-headers-cleanup.patch
ptrace-give-more-respect-to-sigkill.patch
ptrace-never-sleep-in-task_traced-if-sigkilled.patch
ptrace-kill-may_ptrace_stop.patch
introduce-pf_kthread-flag.patch
kill-pf_borrowed_mm-in-favour-of-pf_kthread.patch
coredump-zap_threads-must-skip-kernel-threads.patch
coredump-elf_core_dump-skip-kernel-threads.patch
coredump-move-mm-core_waiters-into-struct-core_state.patch
coredump-simplify-core_state-nr_threads-calculation.patch
coredump-turn-core_state-nr_threads-into-atomic_t.patch
pidns-remove-now-unused-kill_proc-function.patch
pidns-remove-now-unused-find_pid-function.patch
pidns-remove-find_task_by_pid-unused-for-a-long-time.patch
distinct-tgid-tid-i-o-statistics.patch
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