Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH -mm] freezer: Fix racy usage of try_to_freeze in kswapd | Date | Tue, 10 Apr 2007 16:21:16 +0200 |
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From: Rafael J. Wysocki <rjw@sisk.pl>
Currently we can miss freeze_process()->signal_wake_up() in kswapd() if it happens between try_to_freeze() and prepare_to_wait(). To prevent this from happening we should check freezing(current) before calling schedule().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- mm/vmscan.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
Index: linux-2.6.21-rc6/mm/vmscan.c =================================================================== --- linux-2.6.21-rc6.orig/mm/vmscan.c +++ linux-2.6.21-rc6/mm/vmscan.c @@ -1323,8 +1323,6 @@ static int kswapd(void *p) for ( ; ; ) { unsigned long new_order; - try_to_freeze(); - prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE); new_order = pgdat->kswapd_max_order; pgdat->kswapd_max_order = 0; @@ -1335,12 +1333,19 @@ static int kswapd(void *p) */ order = new_order; } else { - schedule(); + if (!freezing(current)) + schedule(); + order = pgdat->kswapd_max_order; } finish_wait(&pgdat->kswapd_wait, &wait); - balance_pgdat(pgdat, order); + if (!try_to_freeze()) { + /* We can speed up thawing tasks if we don't call + * balance_pgdat after returning from the refrigerator + */ + balance_pgdat(pgdat, order); + } } return 0; } - 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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