From: Oleg Nesterov Date: Tue, 29 Aug 2006 07:15:14 +0000 (+0200) Subject: [PATCH] exit_io_context: don't disable irqs X-Git-Tag: v2.6.19-rc1~640^2~26 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=25034d7a83cf77667f3d65822484b305d4be6b25;p=linux-2.6 [PATCH] exit_io_context: don't disable irqs We don't need to disable irqs to clear current->io_context, it is protected by ->alloc_lock. Even IF it was possible to submit I/O from IRQ on behalf of current this irq_disable() can't help: current_io_context() will re-instantiate ->io_context after irq_enable(). We don't need task_lock() or local_irq_disable() to clear ioc->task. This can't prevent other CPUs from playing with our io_context anyway. Signed-off-by: Oleg Nesterov Signed-off-by: Jens Axboe --- diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 57992ae511..f757ed4132 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -3629,25 +3629,22 @@ EXPORT_SYMBOL(put_io_context); /* Called by the exitting task */ void exit_io_context(void) { - unsigned long flags; struct io_context *ioc; struct cfq_io_context *cic; - local_irq_save(flags); task_lock(current); ioc = current->io_context; current->io_context = NULL; - ioc->task = NULL; task_unlock(current); - local_irq_restore(flags); + ioc->task = NULL; if (ioc->aic && ioc->aic->exit) ioc->aic->exit(ioc->aic); if (ioc->cic_root.rb_node != NULL) { cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node); cic->exit(ioc); } - + put_io_context(ioc); }