From 5aae246f1e1c59511a82398d88128e9fc9357107 Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Fri, 26 Dec 2014 18:10:59 -0800 Subject: [PATCH] runtime: increase number of stack orders to 4 Cache 2KB, 4KB, 8KB, and 16KB stacks. Larger stacks will be allocated directly. There is no point in cacheing 32KB+ stacks as we ask for and return 32KB at a time from the allocator. Note that the minimum stack is 8K on windows/64bit and 4K on windows/32bit and plan9. For these os/arch combinations, the number of stack orders is less so that we have the same maximum cached size. Fixes #9045 Change-Id: Ia4195dd1858fb79fc0e6a91ae29c374d28839e44 Reviewed-on: https://go-review.googlesource.com/2098 Reviewed-by: Russ Cox --- src/runtime/malloc2.go | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/src/runtime/malloc2.go b/src/runtime/malloc2.go index 8cdf668214..54321e9c08 100644 --- a/src/runtime/malloc2.go +++ b/src/runtime/malloc2.go @@ -117,7 +117,17 @@ const ( // Number of orders that get caching. Order 0 is FixedStack // and each successive order is twice as large. - _NumStackOrders = 3 + // We want to cache 2KB, 4KB, 8KB, and 16KB stacks. Larger stacks + // will be allocated directly. + // Since FixedStack is different on different systems, we + // must vary NumStackOrders to keep the same maximum cached size. + // OS | FixedStack | NumStackOrders + // -----------------+------------+--------------- + // linux/darwin/bsd | 2KB | 4 + // windows/32 | 4KB | 3 + // windows/64 | 8KB | 2 + // plan9 | 4KB | 3 + _NumStackOrders = 4 - ptrSize/4*goos_windows - 1*goos_plan9 // Number of bits in page to span calculations (4k pages). // On Windows 64-bit we limit the arena to 32GB or 35 bits. -- 2.48.1