Messages in this thread Patch in this message | | | Date | Sun, 27 Aug 2006 00:31:42 +0400 | From | Oleg Nesterov <> | Subject | [PATCH] exit_io_context: don't disable irqs |
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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 <oleg@tv-sign.ru>
--- 2.6.18-rc4/block/ll_rw_blk.c~6_exit 2006-08-27 00:10:53.000000000 +0400 +++ 2.6.18-rc4/block/ll_rw_blk.c 2006-08-27 00:11:47.000000000 +0400 @@ -3580,25 +3580,22 @@ 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); } - 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/
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