Date: Fri, 15 Feb 2013 14:48:06 +0000 (UTC) From: Attilio Rao <attilio@FreeBSD.org> To: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: svn commit: r246834 - user/attilio/vmc-playground/sys/vm Message-ID: <201302151448.r1FEm6oW083095@svn.freebsd.org>
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Author: attilio Date: Fri Feb 15 14:48:06 2013 New Revision: 246834 URL: http://svnweb.freebsd.org/changeset/base/246834 Log: Improve dynamic branch prediction and i-cache utilization: - Use predict_false() to tag boot-time cache decisions - Compact boot-time cache allocation into a separate, non-inline, function that won't be called most of the times. Sponsored by: EMC / Isilon storage division Modified: user/attilio/vmc-playground/sys/vm/vm_radix.c Modified: user/attilio/vmc-playground/sys/vm/vm_radix.c ============================================================================== --- user/attilio/vmc-playground/sys/vm/vm_radix.c Fri Feb 15 14:22:23 2013 (r246833) +++ user/attilio/vmc-playground/sys/vm/vm_radix.c Fri Feb 15 14:48:06 2013 (r246834) @@ -128,6 +128,18 @@ vm_radix_node_zone_dtor(void *mem, int s } #endif +static struct vm_radix_node * +vm_radix_carve_bootcache(void) +{ + struct vm_radix_node *rnode; + + if (boot_cache_cnt == VM_RADIX_BOOT_CACHE) + panic("%s: Increase VM_RADIX_BOOT_CACHE", __func__); + rnode = &boot_cache[boot_cache_cnt]; + boot_cache_cnt++; + return (rnode); +} + /* * Allocate a radix node. Pre-allocation ensures that the request will be * always successfully satisfied. @@ -137,12 +149,9 @@ vm_radix_node_get(vm_pindex_t owner, uin { struct vm_radix_node *rnode; - if (boot_cache_cnt <= VM_RADIX_BOOT_CACHE) { - if (boot_cache_cnt == VM_RADIX_BOOT_CACHE) - panic("%s: Increase VM_RADIX_BOOT_CACHE", __func__); - rnode = &boot_cache[boot_cache_cnt]; - boot_cache_cnt++; - } else { + if (__predict_false(boot_cache_cnt <= VM_RADIX_BOOT_CACHE)) + rnode = vm_radix_carve_bootcache(); + else { rnode = uma_zalloc(vm_radix_node_zone, M_NOWAIT | M_ZERO); /* @@ -173,7 +182,8 @@ static __inline void vm_radix_node_put(struct vm_radix_node *rnode) { - if (rnode > boot_cache && rnode <= &boot_cache[VM_RADIX_BOOT_CACHE]) + if (__predict_false(rnode > boot_cache && + rnode <= &boot_cache[VM_RADIX_BOOT_CACHE])) return; uma_zfree(vm_radix_node_zone, rnode); }
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