Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932421AbVJYWHV (ORCPT ); Tue, 25 Oct 2005 18:07:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932434AbVJYWFj (ORCPT ); Tue, 25 Oct 2005 18:05:39 -0400 Received: from [151.97.230.9] ([151.97.230.9]:60645 "EHLO ssc.unict.it") by vger.kernel.org with ESMTP id S932432AbVJYWFc (ORCPT ); Tue, 25 Oct 2005 18:05:32 -0400 From: "Paolo 'Blaisorblade' Giarrusso" Subject: [PATCH 10/11] uml: avoid malloc to sleep in atomic sections Date: Wed, 26 Oct 2005 00:02:54 +0200 To: Jeff Dike Cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net Message-Id: <20051025220253.20010.96269.stgit@zion.home.lan> In-Reply-To: <20051025220053.20010.56979.stgit@zion.home.lan> References: <20051025220053.20010.56979.stgit@zion.home.lan> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4254 Lines: 141 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/helper.c | 4 ++-- arch/um/kernel/main.c | 11 +++++++---- arch/um/kernel/process_kern.c | 21 +++++++++++++-------- 5 files changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/um/include/kern_util.h b/arch/um/include/kern_util.h --- a/arch/um/include/kern_util.h +++ b/arch/um/include/kern_util.h @@ -109,9 +109,11 @@ 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); + #endif /* diff --git a/arch/um/include/user.h b/arch/um/include/user.h --- 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/helper.c b/arch/um/kernel/helper.c --- a/arch/um/kernel/helper.c +++ b/arch/um/kernel/helper.c @@ -61,7 +61,7 @@ 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 *); diff --git a/arch/um/kernel/main.c b/arch/um/kernel/main.c --- a/arch/um/kernel/main.c +++ b/arch/um/kernel/main.c @@ -197,11 +197,14 @@ void *__wrap_malloc(int size) { void *ret; - if(!CAN_KMALLOC()) + if (!CAN_KMALLOC()) return(__real_malloc(size)); - else if(size <= PAGE_SIZE) /* finding contiguos pages can be hard*/ - ret = um_kmalloc(size); - else ret = um_vmalloc(size); + else if (size <= PAGE_SIZE) /* finding contiguos pages can be hard*/ + ret = __cant_sleep() ? um_kmalloc_atomic(size) : + um_kmalloc(size); + else + ret = __cant_sleep() ? um_vmalloc_atomic(size) : + um_vmalloc(size); /* glibc people insist that if malloc fails, errno should be * set by malloc as well. So we do. diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c --- a/arch/um/kernel/process_kern.c +++ b/arch/um/kernel/process_kern.c @@ -287,17 +287,27 @@ 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) @@ -373,11 +383,6 @@ int smp_sigio_handler(void) return(0); } -int um_in_interrupt(void) -{ - return(in_interrupt()); -} - int cpu(void) { return(current_thread->cpu); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/