systemd/journald-advice-about-use-of-memory.patch

From: werner@suse.de
Upstream: marked as openSUSE-specific fix originally, but may well
	worth be to be sent upstream.

Original description:
	(none)

Notes [jengelh@inai.de]:
MAP_NONBLOCK is documented (mmap(2) in man-pages-3.69+) to render
MAP_POPULATE ineffective. Why do we have it?
What is the rationale for MAP_STACK?
---
 src/journal/catalog.c              |   12 +++++++++++-
 src/journal/journal-authenticate.c |    7 +++++--
 src/journal/journald-kmsg.c        |    3 ++-
 src/journal/mmap-cache.c           |   16 +++++++++++++++-
 4 files changed, 33 insertions(+), 5 deletions(-)

Index: systemd/src/journal/catalog.c
===================================================================
--- systemd.orig/src/journal/catalog.c
+++ systemd/src/journal/catalog.c
@@ -470,6 +470,10 @@ finish:
 
 static int open_mmap(const char *database, int *_fd, struct stat *_st, void **_p) {
         const CatalogHeader *h;
+        static const unsigned int advice[] =
+                {MADV_WILLNEED, MADV_SEQUENTIAL, MADV_DONTDUMP, MADV_DONTFORK};
+        unsigned int n;
+        size_t psize;
         int fd;
         void *p;
         struct stat st;
@@ -492,12 +496,18 @@ static int open_mmap(const char *databas
                 return -EINVAL;
         }
 
-        p = mmap(NULL, PAGE_ALIGN(st.st_size), PROT_READ, MAP_SHARED, fd, 0);
+        psize = PAGE_ALIGN(st.st_size);
+        p = mmap(NULL, psize, PROT_READ, MAP_SHARED | MAP_POPULATE |
+                 MAP_NONBLOCK, fd, 0);
         if (p == MAP_FAILED) {
                 safe_close(fd);
                 return -errno;
         }
 
+        for (n = 0; n < sizeof(advice) / sizeof(*advice); ++n)
+                if (madvise(p, psize, advice[n]) < 0)
+                        log_warning("Failed to give advice about use of memory: %m");
+
         h = p;
         if (memcmp(h->signature, CATALOG_SIGNATURE, sizeof(h->signature)) != 0 ||
             le64toh(h->header_size) < sizeof(CatalogHeader) ||
Index: systemd/src/journal/journal-authenticate.c
===================================================================
--- systemd.orig/src/journal/journal-authenticate.c
+++ systemd/src/journal/journal-authenticate.c
@@ -355,7 +355,8 @@ int journal_file_fss_load(JournalFile *f
                 goto finish;
         }
 
-        m = mmap(NULL, PAGE_ALIGN(sizeof(FSSHeader)), PROT_READ, MAP_SHARED, fd, 0);
+        m = mmap(NULL, PAGE_ALIGN(sizeof(FSSHeader)), PROT_READ,
+                 MAP_SHARED | MAP_STACK, fd, 0);
         if (m == MAP_FAILED) {
                 m = NULL;
                 r = -errno;
@@ -399,7 +400,9 @@ int journal_file_fss_load(JournalFile *f
                 goto finish;
         }
 
-        f->fss_file = mmap(NULL, PAGE_ALIGN(f->fss_file_size), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+        f->fss_file = mmap(NULL, PAGE_ALIGN(f->fss_file_size),
+                           PROT_READ | PROT_WRITE, MAP_SHARED | MAP_STACK,
+                           fd, 0);
         if (f->fss_file == MAP_FAILED) {
                 f->fss_file = NULL;
                 r = -errno;
Index: systemd/src/journal/journald-kmsg.c
===================================================================
--- systemd.orig/src/journal/journald-kmsg.c
+++ systemd/src/journal/journald-kmsg.c
@@ -454,7 +454,8 @@ int server_open_kernel_seqnum(Server *s)
                 return 0;
         }
 
-        p = mmap(NULL, sizeof(uint64_t), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+        p = mmap(NULL, sizeof(uint64_t), PROT_READ | PROT_WRITE,
+                 MAP_SHARED | MAP_STACK, fd, 0);
         if (p == MAP_FAILED) {
                 log_error_errno(errno, "Failed to map sequential number file, ignoring: %m");
                 return 0;
Index: systemd/src/journal/mmap-cache.c
===================================================================
--- systemd.orig/src/journal/mmap-cache.c
+++ systemd/src/journal/mmap-cache.c
@@ -467,11 +467,14 @@ static int add_mmap(
                 struct stat *st,
                 void **ret) {
 
+        static const unsigned int advice[] =
+                {MADV_WILLNEED, MADV_SEQUENTIAL, MADV_DONTDUMP, MADV_DONTFORK};
         uint64_t woffset, wsize;
         Context *c;
         FileDescriptor *f;
         Window *w;
         void *d;
+        unsigned int n;
         int r;
 
         assert(m);
@@ -510,7 +513,8 @@ static int add_mmap(
         }
 
         for (;;) {
-                d = mmap(NULL, wsize, prot, MAP_SHARED, fd, woffset);
+                d = mmap(NULL, wsize, prot, MAP_SHARED | MAP_POPULATE |
+                         MAP_NONBLOCK, fd, woffset);
                 if (d != MAP_FAILED)
                         break;
                 if (errno != ENOMEM)
@@ -523,6 +527,16 @@ static int add_mmap(
                         return -ENOMEM;
         }
 
+        for (n = 0; n < sizeof(advice) / sizeof(*advice); ++n) {
+                if (advice[n] == MADV_DONTFORK) {
+                        int flags = fcntl(fd, F_GETFD);
+                        if (flags < 0 || !(flags & FD_CLOEXEC))
+                                continue;
+                }
+                if (madvise(d, wsize, advice[n]) < 0)
+                        log_warning("Failed to give advice about use of memory: %m");
+        }
+
         c = context_add(m, context);
         if (!c)
                 goto outofmem;