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Paul E. McKenney ed2bec07fd documentation: Record reason for rcu_head two-byte alignment There is an assertion in __call_rcu() that checks only the bottom bit of the rcu_head pointer, rather than the bottom two (as might be expected for 32-bit systems) or the bottom three (as might be expected for 64-bit systems). This choice might be a bit surprising in these days of ubiquitous 32-bit and 64-bit systems. This commit therefore records the reason for this odd alignment check, namely that m68k guarantees only two-byte alignment despite being a 32-bit architectures. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>	History 2016-08-22 09:25:33 -07:00
..
Data-Structures	documentation: Add documentation for RCU's major data structures	2016-04-19 14:48:12 -07:00
Requirements	documentation: Record reason for rcu_head two-byte alignment	2016-08-22 09:25:33 -07:00

Paul E. McKenney ed2bec07fd documentation: Record reason for rcu_head two-byte alignment

There is an assertion in __call_rcu() that checks only the bottom
bit of the rcu_head pointer, rather than the bottom two (as might be
expected for 32-bit systems) or the bottom three (as might be expected
for 64-bit systems).  This choice might be a bit surprising in these days
of ubiquitous 32-bit and 64-bit systems.  This commit therefore records
the reason for this odd alignment check, namely that m68k guarantees
only two-byte alignment despite being a 32-bit architectures.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

History

2016-08-22 09:25:33 -07:00

Data-Structures

documentation: Add documentation for RCU's major data structures

2016-04-19 14:48:12 -07:00

Requirements

documentation: Record reason for rcu_head two-byte alignment

2016-08-22 09:25:33 -07:00