tventi: work around gcc 4.3 bug (reported by Lucho Ionkov) - plan9port - [fork] Plan 9 from user space (HTM) git clone git://src.adamsgaard.dk/plan9port (DIR) Log (DIR) Files (DIR) Refs (DIR) README (DIR) LICENSE --- (DIR) commit dce4cbabd1bbfa3a8acc05ae0b2c3a9df17f93d2 (DIR) parent 17b19538a48c036dbdc8817d233c0086f327485c (HTM) Author: Russ Cox <rsc@swtch.com> Date: Thu, 31 Jul 2008 15:41:54 -0400 venti: work around gcc 4.3 bug (reported by Lucho Ionkov) Diffstat: M src/cmd/venti/srv/icache.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- (DIR) diff --git a/src/cmd/venti/srv/icache.c b/src/cmd/venti/srv/icache.c t@@ -15,7 +15,19 @@ struct ICache IHash *hash; IEntry *entries; int nentries; - IEntry free; + + /* + * gcc 4.3 inlines the pushfirst loop in initicache, + * but the inliner incorrectly deduces that + * icache.free.next has a constant value + * throughout the loop. (In fact, pushfirst + * assigns to it as ie->prev->next.) + * Marking it volatile should avoid this bug. + * The speed of linked list operations is dwarfed + * by the disk i/o anyway. + */ + volatile IEntry free; + IEntry clean; IEntry dirty; u32int maxdirty;