summaryrefslogtreecommitdiff
path: root/debian/patches/ext2fs-two-pagers.patch
diff options
context:
space:
mode:
Diffstat (limited to 'debian/patches/ext2fs-two-pagers.patch')
-rw-r--r--debian/patches/ext2fs-two-pagers.patch214
1 files changed, 214 insertions, 0 deletions
diff --git a/debian/patches/ext2fs-two-pagers.patch b/debian/patches/ext2fs-two-pagers.patch
new file mode 100644
index 00000000..808559d8
--- /dev/null
+++ b/debian/patches/ext2fs-two-pagers.patch
@@ -0,0 +1,214 @@
+commit 553d9fb8e1b04f96f826d512371e5cc4e741c4d0
+Author: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Sat Apr 26 19:48:18 2014 +0200
+
+ ext2fs: use two distinct pager buckets for the disk and file pager
+
+ ext2fs has two kinds of pagers. One for the files, one for the disk.
+ Previously, both were in the same port bucket.
+
+ If a request for a file pager arrives, it most likely touches some
+ metadata (like the superblock). This is in turn backed by the disk
+ pager, so another request is generated for the disk pager.
+
+ Seperate all pagers clearly by using two port buckets. This will
+ enable us to use a single thread per port bucket in the future.
+
+ * ext2fs/pager.c (pager_bucket): Rename to...
+ (disk_pager_bucket
+
+diff --git a/ext2fs/pager.c b/ext2fs/pager.c
+index 6e99c83..c979197 100644
+--- a/ext2fs/pager.c
++++ b/ext2fs/pager.c
+@@ -27,8 +27,11 @@
+ /* XXX */
+ #include "../libpager/priv.h"
+
+-/* A ports bucket to hold pager ports. */
+-struct port_bucket *pager_bucket;
++/* A ports bucket to hold disk pager ports. */
++struct port_bucket *disk_pager_bucket;
++
++/* A ports bucket to hold file pager ports. */
++struct port_bucket *file_pager_bucket;
+
+ pthread_spinlock_t node_to_page_lock = PTHREAD_SPINLOCK_INITIALIZER;
+
+@@ -1188,21 +1191,46 @@ disk_cache_block_is_ref (block_t block)
+ return ref;
+ }
+
+-/* Create the DISK pager. */
++/* A top-level function for the paging thread that just services paging
++ requests. */
++static void *
++service_paging_requests (void *arg)
++{
++ struct port_bucket *pager_bucket = arg;
++ ports_manage_port_operations_multithread (pager_bucket,
++ pager_demuxer,
++ 1000,
++ 0,
++ NULL);
++ /* Not reached. */
++ return NULL;
++}
++
++/* Create the disk pager, and the file pager. */
+ void
+ create_disk_pager (void)
+ {
++ pthread_t thread;
++ error_t err;
+ struct user_pager_info *upi = malloc (sizeof (struct user_pager_info));
+ if (!upi)
+ ext2_panic ("can't create disk pager: %s", strerror (errno));
+ upi->type = DISK;
+- pager_bucket = ports_create_bucket ();
++ disk_pager_bucket = ports_create_bucket ();
+ get_hypermetadata ();
+ disk_cache_blocks = DISK_CACHE_BLOCKS;
+ disk_cache_size = disk_cache_blocks << log2_block_size;
+- diskfs_start_disk_pager (upi, pager_bucket, MAY_CACHE, 1,
++ diskfs_start_disk_pager (upi, disk_pager_bucket, MAY_CACHE, 1,
+ disk_cache_size, &disk_cache);
+ disk_cache_init ();
++
++ file_pager_bucket = ports_create_bucket ();
++ /* Make a thread to service file paging requests. */
++ err = pthread_create (&thread, /* XXX */ NULL,
++ service_paging_requests, file_pager_bucket);
++ if (err)
++ error (2, err, "pthread_create");
++ pthread_detach (thread);
+ }
+
+ /* Call this to create a FILE_DATA pager and return a send right.
+@@ -1241,7 +1269,7 @@ diskfs_get_filemap (struct node *node, vm_prot_t prot)
+ upi->max_prot = prot;
+ diskfs_nref_light (node);
+ node->dn->pager =
+- pager_create (upi, pager_bucket, MAY_CACHE,
++ pager_create (upi, file_pager_bucket, MAY_CACHE,
+ MEMORY_OBJECT_COPY_DELAY, 0);
+ if (node->dn->pager == 0)
+ {
+@@ -1324,14 +1352,13 @@ diskfs_shutdown_pager ()
+ error_t shutdown_one (void *v_p)
+ {
+ struct pager *p = v_p;
+- if (p != diskfs_disk_pager)
+- pager_shutdown (p);
++ pager_shutdown (p);
+ return 0;
+ }
+
+ write_all_disknodes ();
+
+- ports_bucket_iterate (pager_bucket, shutdown_one);
++ ports_bucket_iterate (file_pager_bucket, shutdown_one);
+
+ /* Sync everything on the the disk pager. */
+ sync_global (1);
+@@ -1347,13 +1374,12 @@ diskfs_sync_everything (int wait)
+ error_t sync_one (void *v_p)
+ {
+ struct pager *p = v_p;
+- if (p != diskfs_disk_pager)
+- pager_sync (p, wait);
++ pager_sync (p, wait);
+ return 0;
+ }
+
+ write_all_disknodes ();
+- ports_bucket_iterate (pager_bucket, sync_one);
++ ports_bucket_iterate (file_pager_bucket, sync_one);
+
+ /* Do things on the the disk pager. */
+ sync_global (wait);
+@@ -1372,7 +1398,8 @@ disable_caching ()
+
+ /* Loop through the pagers and turn off caching one by one,
+ synchronously. That should cause termination of each pager. */
+- ports_bucket_iterate (pager_bucket, block_cache);
++ ports_bucket_iterate (disk_pager_bucket, block_cache);
++ ports_bucket_iterate (file_pager_bucket, block_cache);
+ }
+
+ static void
+@@ -1400,7 +1427,8 @@ enable_caching ()
+ return 0;
+ }
+
+- ports_bucket_iterate (pager_bucket, enable_cache);
++ ports_bucket_iterate (disk_pager_bucket, enable_cache);
++ ports_bucket_iterate (file_pager_bucket, enable_cache);
+ }
+
+ /* Tell diskfs if there are pagers exported, and if none, then
+@@ -1408,7 +1436,7 @@ enable_caching ()
+ int
+ diskfs_pager_users ()
+ {
+- int npagers = ports_count_bucket (pager_bucket);
++ int npagers = ports_count_bucket (file_pager_bucket);
+
+ if (npagers <= 1)
+ return 0;
+@@ -1421,8 +1449,8 @@ diskfs_pager_users ()
+ immediately. XXX */
+ sleep (1);
+
+- npagers = ports_count_bucket (pager_bucket);
+- if (npagers <= 1)
++ npagers = ports_count_bucket (file_pager_bucket);
++ if (npagers == 0)
+ return 0;
+
+ /* Darn, there are actual honest users. Turn caching back on,
+@@ -1430,7 +1458,7 @@ diskfs_pager_users ()
+ enable_caching ();
+ }
+
+- ports_enable_bucket (pager_bucket);
++ ports_enable_bucket (file_pager_bucket);
+
+ return 1;
+ }
+@@ -1441,17 +1469,15 @@ vm_prot_t
+ diskfs_max_user_pager_prot ()
+ {
+ vm_prot_t max_prot = 0;
+- int npagers = ports_count_bucket (pager_bucket);
++ int npagers = ports_count_bucket (file_pager_bucket);
+
+- if (npagers > 1)
+- /* More than just the disk pager. */
++ if (npagers > 0)
+ {
+ error_t add_pager_max_prot (void *v_p)
+ {
+ struct pager *p = v_p;
+ struct user_pager_info *upi = pager_get_upi (p);
+- if (upi->type == FILE_DATA)
+- max_prot |= upi->max_prot;
++ max_prot |= upi->max_prot;
+ /* Stop iterating if MAX_PROT is as filled as it's going to get. */
+ return
+ (max_prot == (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)) ? 1 : 0;
+@@ -1463,12 +1489,12 @@ diskfs_max_user_pager_prot ()
+ immediately. XXX */
+ sleep (1);
+
+- ports_bucket_iterate (pager_bucket, add_pager_max_prot);
++ ports_bucket_iterate (file_pager_bucket, add_pager_max_prot);
+
+ enable_caching ();
+ }
+
+- ports_enable_bucket (pager_bucket);
++ ports_enable_bucket (file_pager_bucket);
+
+ return max_prot;
+ }
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 02:34:46 +0000