old MADV_DONTDUMP patch

gistfile1.txt

commit 77444bb6dca702e075aa44f7b4c7358e87927163
Author: Nils Goroll <nils.goroll@uplex.de>
Date:   Mon Apr 25 16:22:50 2016 +0200

    MADV_DONTDUMP

diff --git a/bin/varnishd/storage/storage_file.c b/bin/varnishd/storage/storage_file.c
index dc15ddf..0915781 100644
--- a/bin/varnishd/storage/storage_file.c
+++ b/bin/varnishd/storage/storage_file.c
@@ -367,6 +367,10 @@ smf_open_chunk(struct smf_sc *sc, off_t sz, off_t off, off_t *fail, off_t *sum)
                    MAP_NOCORE | MAP_NOSYNC | MAP_SHARED, sc->fd, off);
                if (p != MAP_FAILED) {
                        (void) madvise(p, sz, MADV_RANDOM);
+#ifdef HAVE_MADV_DONTDUMP
+                       if (DO_DEBUG(DBG_STV_DONTDUMP))
+                               (void) madvise(p, sz, MADV_DONTDUMP);
+#endif
                        (*sum) += sz;
                        new_smf(sc, p, off, sz);
                        return;
diff --git a/bin/varnishd/storage/storage_malloc.c b/bin/varnishd/storage/storage_malloc.c
index a936b2d..b69920d 100644
--- a/bin/varnishd/storage/storage_malloc.c
+++ b/bin/varnishd/storage/storage_malloc.c
@@ -31,6 +31,10 @@
 
 #include "config.h"
 
+#ifdef HAVE_MADV_DONTDUMP
+#include <sys/mman.h>
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -122,6 +126,11 @@ sma_alloc(const struct stevedore *st, size_t size)
        sma->s.len = 0;
        sma->s.space = size;
        sma->s.magic = STORAGE_MAGIC;
+
+#ifdef HAVE_MADV_DONTDUMP
+       if (DO_DEBUG(DBG_STV_DONTDUMP))
+               (void) madvise(sma->s.ptr, sma->sz, MADV_DONTDUMP);
+#endif
        return (&sma->s);
 }
 
@@ -143,6 +152,10 @@ sma_free(struct storage *s)
        if (sma_sc->sma_max != SIZE_MAX)
                sma_sc->stats->g_space += sma->sz;
        Lck_Unlock(&sma_sc->sma_mtx);
+#ifdef HAVE_MADV_DONTDUMP
+       if (DO_DEBUG(DBG_STV_DONTDUMP))
+               (void) madvise(sma->s.ptr, sma->sz, MADV_DODUMP);
+#endif
        free(sma->s.ptr);
        free(sma);
 }
diff --git a/configure.ac b/configure.ac
index edba56a..46bb52e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -530,6 +530,11 @@ if test "$ac_cv_have_tcp_keep" = yes; then
 fi
 LIBS="${save_LIBS}"
 
+AC_CHECK_DEFINE([sys/mman.h],[MADV_DONTDUMP],
+       AC_DEFINE([HAVE_MADV_DONTDUMP], [1],
+                 [Define if madvise knows about MADV_DONTDUMP]))
+
+
 # Run-time directory
 VARNISH_STATE_DIR='${localstatedir}/varnish'
 AC_SUBST(VARNISH_STATE_DIR)
diff --git a/include/tbl/debug_bits.h b/include/tbl/debug_bits.h
index fa0d32f..14a4ad0 100644
--- a/include/tbl/debug_bits.h
+++ b/include/tbl/debug_bits.h
@@ -43,4 +43,5 @@ DEBUG_BIT(FLUSH_HEAD,         flush_head,     "Flush after http1 head")
 DEBUG_BIT(VTC_MODE,            vtc_mode,       "Varnishtest Mode")
 DEBUG_BIT(WITNESS,             witness,        "Emit WITNESS lock records")
 DEBUG_BIT(VSM_KEEP,            vsm_keep,       "Keep the VSM file on restart")
+DEBUG_BIT(STV_DONTDUMP,        stv_dontdump,   "Reduce core size by calling madvise(MADV_DONTDUMP) on stevedore allocations")
 /*lint -restore */