Two-phase queue run perf: parallel processes for phase one

[users/jgh/exim.git] / doc / doc-txt / ChangeLog

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 43b306d3b8d787989746c3cc3844a0bbc4205fd0..3b160cb86011b15390a6bbbb7218f068bcba3d6e 100644 (file)
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -100,19 +100,21 @@ JH/21 Bug 2501: Fix init call in the heimdal authenticator.  Previously it
       buffer was in use at the time.  Change to a compile-time increase in the
       buffer size, when this authenticator is compiled into exim.
 
-JH/22 Taint checking: move to a hybrid approach for checking.  Previously, one
-      of two ways was used, depending on a build-time flag.  The fast method
-      relied on assumptions about the OS and libc malloc, which were known to
-      not hold for the BSD-derived platforms, and discovered to not hold for
-      32-bit Linux either.  In fact the glibc documentation describes cases
-      where these assumptions do not hold.  The new implementation tests for
-      the situation arising and actively switches over from fast to safe mode.
+JH/22 Taint-checking: move to safe-mode taint checking on all platforms.  The
+      previous fast-mode was untenable in the face of glibs using mmap to
+      support larger malloc requests.
 
 PP/01 Update the openssl_options possible values through OpenSSL 1.1.1c.
       New values supported, if defined on system where compiled:
       allow_no_dhe_kex, cryptopro_tlsext_bug, enable_middlebox_compat,
       no_anti_replay, no_encrypt_then_mac, prioritize_chacha, tlsext_padding
 
+JH/23 Performance improvement in the initial phase of a two-pass queue run.  By
+      running a limited number of proceses in parallel, a benefit is gained. The
+      amount varies with the platform hardware and load.  The use of the option
+      queue_run_in_order means we cannot do this, as ordering becomes
+      indeterminate.
+
 
 Exim version 4.93
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