From 3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 24 Jun 2005 23:13:50 -0700 Subject: [PATCH] Cleanup patch for process freezing 1. Establish a simple API for process freezing defined in linux/include/sched.h: frozen(process) Check for frozen process freezing(process) Check if a process is being frozen freeze(process) Tell a process to freeze (go to refrigerator) thaw_process(process) Restart process frozen_process(process) Process is frozen now 2. Remove all references to PF_FREEZE and PF_FROZEN from all kernel sources except sched.h 3. Fix numerous locations where try_to_freeze is manually done by a driver 4. Remove the argument that is no longer necessary from two function calls. 5. Some whitespace cleanup 6. Clear potential race in refrigerator (provides an open window of PF_FREEZE cleared before setting PF_FROZEN, recalc_sigpending does not check PF_FROZEN). This patch does not address the problem of freeze_processes() violating the rule that a task may only modify its own flags by setting PF_FREEZE. This is not clean in an SMP environment. freeze(process) is therefore not SMP safe! Signed-off-by: Christoph Lameter Signed-off-by: Linus Torvalds --- arch/i386/kernel/io_apic.c | 2 +- arch/i386/kernel/signal.c | 4 +--- 2 files changed, 2 insertions(+), 4 deletions(-) (limited to 'arch/i386') diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c index 08540bc4ba3e..2451a3a99440 100644 --- a/arch/i386/kernel/io_apic.c +++ b/arch/i386/kernel/io_apic.c @@ -573,7 +573,7 @@ static int balanced_irq(void *unused) for ( ; ; ) { set_current_state(TASK_INTERRUPTIBLE); time_remaining = schedule_timeout(time_remaining); - try_to_freeze(PF_FREEZE); + try_to_freeze(); if (time_after(jiffies, prev_balance_time+balanced_irq_interval)) { do_irq_balance(); diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c index b9b8f4e20fad..ac5b1e975c5c 100644 --- a/arch/i386/kernel/signal.c +++ b/arch/i386/kernel/signal.c @@ -608,10 +608,8 @@ int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset) if (!user_mode(regs)) return 1; - if (current->flags & PF_FREEZE) { - refrigerator(0); + if (try_to_freeze) goto no_signal; - } if (!oldset) oldset = ¤t->blocked; -- cgit v1.2.3-58-ga151