perf(gatsby-plugin-sharp): change approach to concurrency for image processing (#28575)

Co-authored-by: gatsbybot <[email protected]>

Author: vladar

packages/gatsby-plugin-sharp/src/gatsby-worker.js

@@ -1,5 +1,6 @@
 const path = require(`path`)
 const queue = require(`async/queue`)
+const { cpuCoreCount } = require(`gatsby-core-utils`)
 const { processFile } = require(`./process-file`)
 
 exports.IMAGE_PROCESSING_JOB_NAME = `IMAGE_PROCESSING`
@@ -31,7 +32,7 @@ const q = queue(
         args.pluginOptions
       )
     ),
-  1
+  cpuCoreCount()
 )
 
 /**

packages/gatsby-plugin-sharp/src/process-file.js

@@ -8,18 +8,16 @@ const imageminMozjpeg = require(`imagemin-mozjpeg`)
 const imageminPngquant = require(`imagemin-pngquant`)
 const { healOptions } = require(`./plugin-options`)
 const { SharpError } = require(`./sharp-error`)
-const { cpuCoreCount, createContentDigest } = require(`gatsby-core-utils`)
+const { createContentDigest } = require(`gatsby-core-utils`)
 
 // Try to enable the use of SIMD instructions. Seems to provide a smallish
 // speedup on resizing heavy loads (~10%). Sharp disables this feature by
 // default as there's been problems with segfaulting in the past but we'll be
 // adventurous and see what happens with it on.
 sharp.simd(true)
 
-// Handle Sharp's concurrency based on the Gatsby CPU count
-// See: http://sharp.pixelplumbing.com/en/stable/api-utility/#concurrency
-// See: https://www.gatsbyjs.org/docs/multi-core-builds/
-sharp.concurrency(cpuCoreCount())
+// Concurrency is handled in gatsby-worker queue instead
+sharp.concurrency(1)
 
 /**
  * @typedef DuotoneArgs