* Sebastian Andrzej Siewior | 2013-11-29 16:14:01 [+0100]: >* Nicholas Mc Guire | 2013-11-23 01:51:58 [+0100]: > >>>From 5c9a0c1510ec29c1e148f66f3c111f52f7565df1 Mon Sep 17 00:00:00 2001 >>From: Nicholas Mc Guire <der.herr@xxxxxxx> >>Date: Fri, 22 Nov 2013 02:41:48 -0500 >>Subject: [PATCH] migrate_disable pushd down in rt_read_trylock >> >> No need to migrate_disable before requesting the lock and no need to >> speculatively disable/enable on every recursive call. migration_disable >> can be done at the latest point in the code before returning an acquired >> ``lock. >> >> patch is on top of 3.12-rt2 >> >> No change of functionality >Applied without this line. and dropped because there is a problem with this: - Now if you read_lock() and then read_try_lock() then migrate_disable() is called by each caller. Also on read_unlock() migrate_enable() is called by each caller. - with patch read_lock() calls migrate_disable() and read_try_lock() does not. Both get the lock. So on read_unlock(), the read_try_lock() owner remains unbalanced. disabling migration prior incrementing read_depth should fix this. >>Signed-off-by: Nicholas Mc Guire <der.herr@xxxxxxx> Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
