Press the secret "use less RAM" button

1 files changed, 72 insertions, 0 deletions

diff --git a/src/bun.js/bindings/ZigGlobalObject.cpp b/src/bun.js/bindings/ZigGlobalObject.cpp
index 13bb51afd..6b58c241f 100644
--- a/src/bun.js/bindings/ZigGlobalObject.cpp
+++ b/src/bun.js/bindings/ZigGlobalObject.cpp
@@ -180,6 +180,7 @@ namespace JSCastingHelpers = JSC::JSCastingHelpers;
 #include "CallSitePrototype.h"
 #include "DOMWrapperWorld-class.h"
 #include "CommonJSModuleRecord.h"
+#include <wtf/RAMSize.h>
 
 constexpr size_t DEFAULT_ERROR_STACK_TRACE_LIMIT = 10;
 
@@ -221,6 +222,8 @@ extern "C" void JSCInitialize(const char* envp[], size_t envc, void (*onCrash)(c
         JSC::Options::showPrivateScriptsInStackTraces() = true;
         JSC::Options::useSetMethods() = true;
 
+        bool didSetForceRAMSize = false;
+
         if (LIKELY(envc > 0)) {
             while (envc--) {
                 const char* env = (const char*)envp[envc];
@@ -233,6 +236,75 @@ extern "C" void JSCInitialize(const char* envp[], size_t envc, void (*onCrash)(c
                 if (UNLIKELY(!JSC::Options::setOption(env + 8))) {
                     onCrash(env, strlen(env));
                 }
+
+                didSetForceRAMSize = didSetForceRAMSize || strcmp(env + 8, "forceRAMSize") == 0;
+            }
+        }
+
+        /*
+         * The Magic "Use Less RAM" button
+         */
+        // # With /= 16,184
+        // cpu: Apple M1 Max
+        // runtime: bun 0.6.10 (arm64-darwin)
+        // benchmark                        time (avg)             (min … max)       p75       p99      p995
+        // ------------------------------------------------------------------- -----------------------------
+        // crypto.createHash("sha512")  953.74 ns/iter   (842.34 ns … 1.11 µs)      1 µs   1.11 µs   1.11 µs
+        // crypto.createHash("sha256")  704.35 ns/iter  (594.42 ns … 912.4 ns) 754.89 ns  912.4 ns  912.4 ns
+        // crypto.createHash("sha1")    608.53 ns/iter (488.66 ns … 724.54 ns) 637.75 ns 724.54 ns 724.54 ns
+        // Peak memory usage: 59 MB
+        // # With /= 8096
+        // cpu: Apple M1 Max
+        // runtime: bun 0.6.10 (arm64-darwin)
+        // benchmark                        time (avg)             (min … max)       p75       p99      p995
+        // ------------------------------------------------------------------- -----------------------------
+        // crypto.createHash("sha512")  821.71 ns/iter   (716.88 ns … 1.01 µs) 859.07 ns   1.01 µs   1.01 µs
+        // crypto.createHash("sha256")  534.89 ns/iter (439.35 ns … 737.17 ns) 576.15 ns  633.4 ns 737.17 ns
+        // crypto.createHash("sha1")     529.1 ns/iter (432.46 ns … 766.94 ns) 566.07 ns 653.13 ns 766.94 ns
+        // Peak memory usage: 60 MB
+        // # With /= 1024
+        // cpu: Apple M1 Max
+        // runtime: bun 0.6.10 (arm64-darwin)
+        // benchmark                        time (avg)             (min … max)       p75       p99      p995
+        // ------------------------------------------------------------------- -----------------------------
+        // crypto.createHash("sha512")  751.13 ns/iter (703.45 ns … 947.73 ns) 754.54 ns 947.73 ns 947.73 ns
+        // crypto.createHash("sha256")  501.47 ns/iter (467.19 ns … 580.84 ns) 505.66 ns 572.42 ns 580.84 ns
+        // crypto.createHash("sha1")    482.16 ns/iter  (452.7 ns … 570.29 ns) 482.74 ns 565.52 ns 570.29 ns
+        // Peak memory usage: 169 MB
+        // # With /= 256
+        // cpu: Apple M1 Max
+        // runtime: bun 0.6.10 (arm64-darwin)
+        // benchmark                        time (avg)             (min … max)       p75       p99      p995
+        // ------------------------------------------------------------------- -----------------------------
+        // crypto.createHash("sha512")  745.25 ns/iter (705.91 ns … 863.73 ns)  747.8 ns 863.73 ns 863.73 ns
+        // crypto.createHash("sha256")  506.94 ns/iter (459.27 ns … 692.93 ns) 514.95 ns 611.72 ns 692.93 ns
+        // crypto.createHash("sha1")    486.19 ns/iter (456.13 ns … 749.72 ns)  487.5 ns 578.84 ns 749.72 ns
+        // Peak memory usage: 270 MB
+        // # Unset
+        // cpu: Apple M1 Max
+        // runtime: bun 0.6.10 (arm64-darwin)
+        // benchmark                        time (avg)             (min … max)       p75       p99      p995
+        // ------------------------------------------------------------------- -----------------------------
+        // crypto.createHash("sha512")  752.96 ns/iter (705.88 ns … 954.63 ns) 758.78 ns 954.63 ns 954.63 ns
+        // crypto.createHash("sha256")  503.72 ns/iter  (466.7 ns … 602.83 ns) 507.22 ns 593.72 ns 602.83 ns
+        // crypto.createHash("sha1")    484.25 ns/iter (454.55 ns … 555.84 ns) 487.96 ns 553.41 ns 555.84 ns
+        // Peak memory usage: 273 MB
+        // # Node.js, for comparison
+        // cpu: Apple M1 Max
+        // runtime: node v20.1.0 (arm64-darwin)
+        // benchmark                        time (avg)             (min … max)       p75       p99      p995
+        // ------------------------------------------------------------------- -----------------------------
+        // crypto.createHash("sha512")    1.82 µs/iter     (1.77 µs … 2.17 µs)   1.84 µs   2.17 µs   2.17 µs
+        // crypto.createHash("sha256")     964 ns/iter    (946.02 ns … 1.1 µs) 962.95 ns    1.1 µs    1.1 µs
+        // crypto.createHash("sha1")    985.26 ns/iter    (956.7 ns … 1.12 µs)      1 µs   1.12 µs   1.12 µs
+        // Peak memory usage: 56 MB
+
+        if (!didSetForceRAMSize) {
+            size_t ramSize = WTF::ramSize();
+            ramSize /= 1024;
+
+            if (ramSize > 0) {
+                JSC::Options::forceRAMSize() = ramSize;
             }
         }