cgroup-rts-threads 0.2.0.0 → 0.2.1.0

raw patch · 3 files changed

+37/−8 lines, 3 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• CHANGELOG.md +4/−0
• cgroup-rts-threads.cabal +1/−1
• src/Control/Concurrent/CGroup.hs +32/−7

@@ -1,5 +1,9 @@ # Revision history for cgroup-rts-threads +## 0.2.1.0++- Support configuring the rounding mode for the CPU quota to capabilities conversion+ ## 0.2.0.0  - Adds support for cgroups v2

@@ -1,6 +1,6 @@ cabal-version:      3.0 name:               cgroup-rts-threads-version:            0.2.0.0+version:            0.2.1.0 synopsis:   A container-/cgroup-aware substitute for the GHC RTS `-N` flag 

@@ -2,6 +2,8 @@ -- @-N@ flag. See 'initRTSThreads'. module Control.Concurrent.CGroup (   initRTSThreads,+  initRTSThreadsWith,+  RoundQuota (..), ) where  import Control.Exception (Exception (..), SomeAsyncException (SomeAsyncException), SomeException, catch, throwIO)@@ -11,6 +13,24 @@ import qualified System.CGroup.V1.CPU as V1 import qualified System.CGroup.V2.CPU as V2 +-- | CPU quotas can be fractions, but the number of RTS capabilities is an integer. This type+-- determines how to round the CPU quota to get to the number of capabilities.+--+-- The names correspond to the similarly named methods of 'RealFrac'.+data RoundQuota+  = CeilingQuota+  | FloorQuota+  | RoundQuota+  deriving (Show, Read, Eq, Ord)++-- | Round a quota.+roundQuota :: RoundQuota -> Ratio.Ratio Int -> Int+roundQuota roundMode =+  case roundMode of+    CeilingQuota -> ceiling+    FloorQuota -> floor+    RoundQuota -> round+ -- | A container-/cgroup-aware substitute for GHC's RTS @-N@ flag. -- -- On most platforms, this sets the number of runtime threads to match the@@ -21,22 +41,27 @@ -- observes the current process' cgroup cpu quota to constrain the number of -- runtime threads. --+-- By default, the number of capabilities is determined by rounding the CPU quota down.+-- -- See 'CPUQuota' initRTSThreads :: IO ()-initRTSThreads = do+initRTSThreads = initRTSThreadsWith FloorQuota++-- | Same as 'initRTSThreads' but lets you specify the quota round mode.+initRTSThreadsWith :: RoundQuota -> IO ()+initRTSThreadsWith roundMode = do   quota <-     V1.getProcessCPUQuota       `fallback` V2.getProcessEffectiveCPUQuota       `fallback` pure NoQuota-  initRTSThreadsFromQuota quota+  initRTSThreadsFromQuota roundMode quota  -- | Use a CPU quota to set the number of runtime threads.-initRTSThreadsFromQuota :: CPUQuota -> IO ()-initRTSThreadsFromQuota NoQuota = defaultInitRTSThreads-initRTSThreadsFromQuota (CPUQuota ratio) = do+initRTSThreadsFromQuota :: RoundQuota -> CPUQuota -> IO ()+initRTSThreadsFromQuota _ NoQuota = defaultInitRTSThreads+initRTSThreadsFromQuota roundMode (CPUQuota ratio) = do   procs <- getNumProcessors-  let capabilities = clamp 1 procs (Ratio.numerator ratio `div` Ratio.denominator ratio)-  setNumCapabilities capabilities+  setNumCapabilities $ clamp 1 procs $ roundQuota roundMode ratio  -- | Set number of runtime threads to the number of available processors. This -- matches the behavior of GHC's RTS @-N@ flag.