master 396f46d904a: bug#61489: Increase BLOCK_ALIGN from 1024 to 32768

[Eli Zaretskii]

branch: master
commit 396f46d904ab7509476b0d824ec2e4d9a231a2df
Author: Konstantin Kharlamov <Hi-Angel@yandex.ru>
Commit: Eli Zaretskii <eliz@gnu.org>

    bug#61489: Increase BLOCK_ALIGN from 1024 to 32768
    
    Originally discovered by Tyler Dodge in his article "Significant Garbage
    Collection Improvement For Emacs".
    
    While testing this change on Archlinux system with Intel i5-7200U CPU,
    average time of garbage collection gets reduced by ≈25%. Other users
    report improvements up to 50%. While monitoring PSS of emacs with and
    without customizations loaded before and after the patch, no
    statistically significant differences were discovered. So overall, this
    change is a win.
    * src/alloc.c (BLOCK_ALIGN): increase from 1024 to 32768.
---
 src/alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/alloc.c b/src/alloc.c
index 6a7037b6bb0..5450586b533 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -1083,7 +1083,7 @@ lisp_free (void *block)
    BLOCK_BYTES and guarantees they are aligned on a BLOCK_ALIGN boundary.  */
 
 /* Byte alignment of storage blocks.  */
-#define BLOCK_ALIGN (1 << 10)
+#define BLOCK_ALIGN (1 << 15)
 verify (POWER_OF_2 (BLOCK_ALIGN));
 
 /* Use aligned_alloc if it or a simple substitute is available.