diff mbox series

[2/2] sheepdog: remove huge BSS object

Message ID 20180522201056.1442-3-pbonzini@redhat.com
State New
Headers show
Series [1/2] sheepdog: cleanup repeated expression | expand

Commit Message

Paolo Bonzini May 22, 2018, 8:10 p.m. UTC 
block/sheepdog.o has a 4M static variable that is 90% of QEMU's whole .bss
section.  Replace it with a heap-allocated block, and make it smaller too
since only the inode header is actually being used.

bss size goes down from 4464280 to 269976.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 block/sheepdog.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

Comments

Philippe Mathieu-Daudé May 22, 2018, 8:26 p.m. UTC | #1 
On 05/22/2018 05:10 PM, Paolo Bonzini wrote:
> block/sheepdog.o has a 4M static variable that is 90% of QEMU's whole .bss
> section.  Replace it with a heap-allocated block, and make it smaller too
> since only the inode header is actually being used.
> 
> bss size goes down from 4464280 to 269976.

\o/

> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>  block/sheepdog.c | 21 +++++++++++----------
>  1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index 23cf5a8430..2068166e3e 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -2940,13 +2940,14 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>      QEMUSnapshotInfo *sn_tab = NULL;
>      unsigned wlen, rlen;
>      int found = 0;
> -    static SheepdogInode inode;
> +    SheepdogInode *inode;
>      unsigned long *vdi_inuse;
>      unsigned int start_nr;
>      uint64_t hval;
>      uint32_t vid;
>  
>      vdi_inuse = g_malloc(max);
> +    inode = g_malloc(SD_INODE_HEADER_SIZE);
>  
>      fd = connect_to_sdog(s, &local_err);
>      if (fd < 0) {
> @@ -2989,7 +2990,7 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>          }
>  
>          /* we don't need to read entire object */
> -        ret = read_object(fd, s->bs, (char *)&inode,
> +        ret = read_object(fd, s->bs, (char *)inode,
>                            vid_to_vdi_oid(vid),
>                            0, SD_INODE_HEADER_SIZE, 0,
>                            s->cache_flags);
> @@ -2998,17 +2999,17 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>              continue;
>          }
>  
> -        if (!strcmp(inode.name, s->name) && is_snapshot(&inode)) {
> -            sn_tab[found].date_sec = inode.snap_ctime >> 32;
> -            sn_tab[found].date_nsec = inode.snap_ctime & 0xffffffff;
> -            sn_tab[found].vm_state_size = inode.vm_state_size;
> -            sn_tab[found].vm_clock_nsec = inode.vm_clock_nsec;
> +        if (!strcmp(inode->name, s->name) && is_snapshot(inode)) {
> +            sn_tab[found].date_sec = inode->snap_ctime >> 32;
> +            sn_tab[found].date_nsec = inode->snap_ctime & 0xffffffff;
> +            sn_tab[found].vm_state_size = inode->vm_state_size;
> +            sn_tab[found].vm_clock_nsec = inode->vm_clock_nsec;
>  
>              snprintf(sn_tab[found].id_str, sizeof(sn_tab[found].id_str),
> -                     "%" PRIu32, inode.snap_id);
> +                     "%" PRIu32, inode->snap_id);
>              pstrcpy(sn_tab[found].name,
> -                    MIN(sizeof(sn_tab[found].name), sizeof(inode.tag)),
> -                    inode.tag);
> +                    MIN(sizeof(sn_tab[found].name), sizeof(inode->tag)),
> +                    inode->tag);
>              found++;
>          }
>      }
>
Fam Zheng May 23, 2018, 1:43 a.m. UTC | #2 
On Tue, 05/22 22:10, Paolo Bonzini wrote:
> block/sheepdog.o has a 4M static variable that is 90% of QEMU's whole .bss
> section.  Replace it with a heap-allocated block, and make it smaller too
> since only the inode header is actually being used.
> 
> bss size goes down from 4464280 to 269976.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  block/sheepdog.c | 21 +++++++++++----------
>  1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index 23cf5a8430..2068166e3e 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -2940,13 +2940,14 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>      QEMUSnapshotInfo *sn_tab = NULL;
>      unsigned wlen, rlen;
>      int found = 0;
> -    static SheepdogInode inode;
> +    SheepdogInode *inode;
>      unsigned long *vdi_inuse;
>      unsigned int start_nr;
>      uint64_t hval;
>      uint32_t vid;
>  
>      vdi_inuse = g_malloc(max);
> +    inode = g_malloc(SD_INODE_HEADER_SIZE);

Should you g_free() it before returning?


>  
>      fd = connect_to_sdog(s, &local_err);
>      if (fd < 0) {
> @@ -2989,7 +2990,7 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>          }
>  
>          /* we don't need to read entire object */
> -        ret = read_object(fd, s->bs, (char *)&inode,
> +        ret = read_object(fd, s->bs, (char *)inode,
>                            vid_to_vdi_oid(vid),
>                            0, SD_INODE_HEADER_SIZE, 0,
>                            s->cache_flags);
> @@ -2998,17 +2999,17 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>              continue;
>          }
>  
> -        if (!strcmp(inode.name, s->name) && is_snapshot(&inode)) {
> -            sn_tab[found].date_sec = inode.snap_ctime >> 32;
> -            sn_tab[found].date_nsec = inode.snap_ctime & 0xffffffff;
> -            sn_tab[found].vm_state_size = inode.vm_state_size;
> -            sn_tab[found].vm_clock_nsec = inode.vm_clock_nsec;
> +        if (!strcmp(inode->name, s->name) && is_snapshot(inode)) {
> +            sn_tab[found].date_sec = inode->snap_ctime >> 32;
> +            sn_tab[found].date_nsec = inode->snap_ctime & 0xffffffff;
> +            sn_tab[found].vm_state_size = inode->vm_state_size;
> +            sn_tab[found].vm_clock_nsec = inode->vm_clock_nsec;
>  
>              snprintf(sn_tab[found].id_str, sizeof(sn_tab[found].id_str),
> -                     "%" PRIu32, inode.snap_id);
> +                     "%" PRIu32, inode->snap_id);
>              pstrcpy(sn_tab[found].name,
> -                    MIN(sizeof(sn_tab[found].name), sizeof(inode.tag)),
> -                    inode.tag);
> +                    MIN(sizeof(sn_tab[found].name), sizeof(inode->tag)),
> +                    inode->tag);
>              found++;
>          }
>      }
> -- 
> 2.17.0
> 
>
Philippe Mathieu-Daudé May 23, 2018, 5:25 p.m. UTC | #3 
On 05/22/2018 10:43 PM, Fam Zheng wrote:
> On Tue, 05/22 22:10, Paolo Bonzini wrote:
>> block/sheepdog.o has a 4M static variable that is 90% of QEMU's whole .bss
>> section.  Replace it with a heap-allocated block, and make it smaller too
>> since only the inode header is actually being used.
>>
>> bss size goes down from 4464280 to 269976.
>>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>>  block/sheepdog.c | 21 +++++++++++----------
>>  1 file changed, 11 insertions(+), 10 deletions(-)
>>
>> diff --git a/block/sheepdog.c b/block/sheepdog.c
>> index 23cf5a8430..2068166e3e 100644
>> --- a/block/sheepdog.c
>> +++ b/block/sheepdog.c
>> @@ -2940,13 +2940,14 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>>      QEMUSnapshotInfo *sn_tab = NULL;
>>      unsigned wlen, rlen;
>>      int found = 0;
>> -    static SheepdogInode inode;
>> +    SheepdogInode *inode;
>>      unsigned long *vdi_inuse;
>>      unsigned int start_nr;
>>      uint64_t hval;
>>      uint32_t vid;
>>  
>>      vdi_inuse = g_malloc(max);
>> +    inode = g_malloc(SD_INODE_HEADER_SIZE);
> 
> Should you g_free() it before returning?

Oops good catch

> 
> 
>>  
>>      fd = connect_to_sdog(s, &local_err);
>>      if (fd < 0) {
>> @@ -2989,7 +2990,7 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>>          }
>>  
>>          /* we don't need to read entire object */
>> -        ret = read_object(fd, s->bs, (char *)&inode,
>> +        ret = read_object(fd, s->bs, (char *)inode,
>>                            vid_to_vdi_oid(vid),
>>                            0, SD_INODE_HEADER_SIZE, 0,
>>                            s->cache_flags);
>> @@ -2998,17 +2999,17 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
>>              continue;
>>          }
>>  
>> -        if (!strcmp(inode.name, s->name) && is_snapshot(&inode)) {
>> -            sn_tab[found].date_sec = inode.snap_ctime >> 32;
>> -            sn_tab[found].date_nsec = inode.snap_ctime & 0xffffffff;
>> -            sn_tab[found].vm_state_size = inode.vm_state_size;
>> -            sn_tab[found].vm_clock_nsec = inode.vm_clock_nsec;
>> +        if (!strcmp(inode->name, s->name) && is_snapshot(inode)) {
>> +            sn_tab[found].date_sec = inode->snap_ctime >> 32;
>> +            sn_tab[found].date_nsec = inode->snap_ctime & 0xffffffff;
>> +            sn_tab[found].vm_state_size = inode->vm_state_size;
>> +            sn_tab[found].vm_clock_nsec = inode->vm_clock_nsec;
>>  
>>              snprintf(sn_tab[found].id_str, sizeof(sn_tab[found].id_str),
>> -                     "%" PRIu32, inode.snap_id);
>> +                     "%" PRIu32, inode->snap_id);
>>              pstrcpy(sn_tab[found].name,
>> -                    MIN(sizeof(sn_tab[found].name), sizeof(inode.tag)),
>> -                    inode.tag);
>> +                    MIN(sizeof(sn_tab[found].name), sizeof(inode->tag)),
>> +                    inode->tag);
>>              found++;
>>          }
>>      }
>> -- 
>> 2.17.0
>>
>>
>
diff mbox series

Patch

diff --git a/block/sheepdog.c b/block/sheepdog.c
index 23cf5a8430..2068166e3e 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2940,13 +2940,14 @@  static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
     QEMUSnapshotInfo *sn_tab = NULL;
     unsigned wlen, rlen;
     int found = 0;
-    static SheepdogInode inode;
+    SheepdogInode *inode;
     unsigned long *vdi_inuse;
     unsigned int start_nr;
     uint64_t hval;
     uint32_t vid;
 
     vdi_inuse = g_malloc(max);
+    inode = g_malloc(SD_INODE_HEADER_SIZE);
 
     fd = connect_to_sdog(s, &local_err);
     if (fd < 0) {
@@ -2989,7 +2990,7 @@  static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
         }
 
         /* we don't need to read entire object */
-        ret = read_object(fd, s->bs, (char *)&inode,
+        ret = read_object(fd, s->bs, (char *)inode,
                           vid_to_vdi_oid(vid),
                           0, SD_INODE_HEADER_SIZE, 0,
                           s->cache_flags);
@@ -2998,17 +2999,17 @@  static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
             continue;
         }
 
-        if (!strcmp(inode.name, s->name) && is_snapshot(&inode)) {
-            sn_tab[found].date_sec = inode.snap_ctime >> 32;
-            sn_tab[found].date_nsec = inode.snap_ctime & 0xffffffff;
-            sn_tab[found].vm_state_size = inode.vm_state_size;
-            sn_tab[found].vm_clock_nsec = inode.vm_clock_nsec;
+        if (!strcmp(inode->name, s->name) && is_snapshot(inode)) {
+            sn_tab[found].date_sec = inode->snap_ctime >> 32;
+            sn_tab[found].date_nsec = inode->snap_ctime & 0xffffffff;
+            sn_tab[found].vm_state_size = inode->vm_state_size;
+            sn_tab[found].vm_clock_nsec = inode->vm_clock_nsec;
 
             snprintf(sn_tab[found].id_str, sizeof(sn_tab[found].id_str),
-                     "%" PRIu32, inode.snap_id);
+                     "%" PRIu32, inode->snap_id);
             pstrcpy(sn_tab[found].name,
-                    MIN(sizeof(sn_tab[found].name), sizeof(inode.tag)),
-                    inode.tag);
+                    MIN(sizeof(sn_tab[found].name), sizeof(inode->tag)),
+                    inode->tag);
             found++;
         }
     }