From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964973AbWARA3q (ORCPT ); Tue, 17 Jan 2006 19:29:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964922AbWARA3p (ORCPT ); Tue, 17 Jan 2006 19:29:45 -0500 Received: from [151.97.230.9] ([151.97.230.9]:12771 "EHLO ssc.unict.it") by vger.kernel.org with ESMTP id S964973AbWARA1i (ORCPT ); Tue, 17 Jan 2006 19:27:38 -0500 From: "Paolo 'Blaisorblade' Giarrusso" Subject: [PATCH 6/9] uml: avoid malloc to sleep in atomic sections Date: Wed, 18 Jan 2006 01:19:40 +0100 To: Andrew Morton Cc: Jeff Dike , linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net Message-Id: <20060118001938.14622.47308.stgit@zion.home.lan> In-Reply-To: <20060117235659.14622.18544.stgit@zion.home.lan> References: <20060117235659.14622.18544.stgit@zion.home.lan> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Paolo 'Blaisorblade' Giarrusso Ugly trick to help make malloc not sleeping - we can't do anything else. But this is not yet optimal, since spinlock don't trigger in_atomic() when preemption is disabled. Also, even if ugly, this was already used in one place, and was even more bogus. Fix it. Signed-off-by: Paolo 'Blaisorblade' Giarrusso --- arch/um/include/kern_util.h | 4 +++- arch/um/include/user.h | 1 + arch/um/kernel/process_kern.c | 21 +++++++++++++-------- arch/um/os-Linux/helper.c | 4 ++-- 4 files changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/um/include/kern_util.h b/arch/um/include/kern_util.h index 8f4e46d..c649108 100644 --- a/arch/um/include/kern_util.h +++ b/arch/um/include/kern_util.h @@ -120,8 +120,10 @@ extern void machine_halt(void); extern int is_syscall(unsigned long addr); extern void arch_switch(void); extern void free_irq(unsigned int, void *); -extern int um_in_interrupt(void); extern int cpu(void); + +/* Are we disallowed to sleep? Used to choose between GFP_KERNEL and GFP_ATOMIC. */ +extern int __cant_sleep(void); extern void segv_handler(int sig, union uml_pt_regs *regs); extern void sigio_handler(int sig, union uml_pt_regs *regs); diff --git a/arch/um/include/user.h b/arch/um/include/user.h index 0f865ef..91b0ac4 100644 --- a/arch/um/include/user.h +++ b/arch/um/include/user.h @@ -18,6 +18,7 @@ extern int open_gdb_chan(void); extern unsigned long strlcpy(char *, const char *, unsigned long); extern unsigned long strlcat(char *, const char *, unsigned long); extern void *um_vmalloc(int size); +extern void *um_vmalloc_atomic(int size); extern void vfree(void *ptr); #endif diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c index 7f13b85..d852c55 100644 --- a/arch/um/kernel/process_kern.c +++ b/arch/um/kernel/process_kern.c @@ -288,17 +288,27 @@ EXPORT_SYMBOL(disable_hlt); void *um_kmalloc(int size) { - return(kmalloc(size, GFP_KERNEL)); + return kmalloc(size, GFP_KERNEL); } void *um_kmalloc_atomic(int size) { - return(kmalloc(size, GFP_ATOMIC)); + return kmalloc(size, GFP_ATOMIC); } void *um_vmalloc(int size) { - return(vmalloc(size)); + return vmalloc(size); +} + +void *um_vmalloc_atomic(int size) +{ + return __vmalloc(size, GFP_ATOMIC | __GFP_HIGHMEM, PAGE_KERNEL); +} + +int __cant_sleep(void) { + return in_atomic() || irqs_disabled() || in_interrupt(); + /* Is in_interrupt() really needed? */ } unsigned long get_fault_addr(void) @@ -370,11 +380,6 @@ int smp_sigio_handler(void) return(0); } -int um_in_interrupt(void) -{ - return(in_interrupt()); -} - int cpu(void) { return(current_thread->cpu); diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c index 36cc847..6490a4f 100644 --- a/arch/um/os-Linux/helper.c +++ b/arch/um/os-Linux/helper.c @@ -60,7 +60,7 @@ int run_helper(void (*pre_exec)(void *), if((stack_out != NULL) && (*stack_out != 0)) stack = *stack_out; - else stack = alloc_stack(0, um_in_interrupt()); + else stack = alloc_stack(0, __cant_sleep()); if(stack == 0) return(-ENOMEM); @@ -124,7 +124,7 @@ int run_helper_thread(int (*proc)(void * unsigned long stack, sp; int pid, status, err; - stack = alloc_stack(stack_order, um_in_interrupt()); + stack = alloc_stack(stack_order, __cant_sleep()); if(stack == 0) return(-ENOMEM); sp = stack + (page_size() << stack_order) - sizeof(void *);