Commit e957b50b authored by Leonid Bloch's avatar Leonid Bloch Committed by Kevin Wolf
Browse files

qcow2: Set the default cache-clean-interval to 10 minutes 



The default cache-clean-interval is set to 10 minutes, in order to lower
the overhead of the qcow2 caches (before the default was 0, i.e.
disabled).

* For non-Linux platforms the default is kept at 0, because
  cache-clean-interval is not supported there yet.

Signed-off-by: default avatarLeonid Bloch <lbloch@janustech.com>
Reviewed-by: default avatarAlberto Garcia <berto@igalia.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 45b4949c

block/qcow2.c

+1 −1
Original line number Diff line number Diff line
@@ -944,7 +944,7 @@ static int qcow2_update_options_prepare(BlockDriverState *bs, 
    /* New interval for cache cleanup timer */

    r->cache_clean_interval =

        qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL,

                            s->cache_clean_interval);

                            DEFAULT_CACHE_CLEAN_INTERVAL);

#ifndef CONFIG_LINUX

    if (r->cache_clean_interval != 0) {

        error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL

block/qcow2.h

+3 −1
Original line number Diff line number Diff line
@@ -76,13 +76,15 @@ 


#ifdef CONFIG_LINUX

#define DEFAULT_L2_CACHE_MAX_SIZE S_32MiB

#define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */

#else

#define DEFAULT_L2_CACHE_MAX_SIZE S_8MiB

/* Cache clean interval is currently available only on Linux, so must be 0 */

#define DEFAULT_CACHE_CLEAN_INTERVAL 0

#endif



#define DEFAULT_CLUSTER_SIZE S_64KiB





#define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"

#define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"

#define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"

docs/qcow2-cache.txt

+2 −2
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@@ -210,8 +210,8 @@ This example removes all unused cache entries every 15 minutes: 


   -drive file=hd.qcow2,cache-clean-interval=900



If unset, the default value for this parameter is 0 and it disables

this feature.

If unset, the default value for this parameter is 600. Setting it to 0

disables this feature.



Note that this functionality currently relies on the MADV_DONTNEED

argument for madvise() to actually free the memory. This is a

qapi/block-core.json

+2 −1
Original line number Diff line number Diff line
@@ -2895,7 +2895,8 @@ 
#

# @cache-clean-interval:  clean unused entries in the L2 and refcount

#                         caches. The interval is in seconds. The default value

#                         is 0 and it disables this feature (since 2.5)

#                         is 600, and 0 disables this feature. (since 2.5)

#

# @encrypt:               Image decryption options. Mandatory for

#                         encrypted images, except when doing a metadata-only

#                         probe of the image. (since 2.10)

qemu-options.hx

+1 −1
Original line number Diff line number Diff line
@@ -747,7 +747,7 @@ it which is not used for the L2 cache) 


@item cache-clean-interval

Clean unused entries in the L2 and refcount caches. The interval is in seconds.

The default value is 0 and it disables this feature.

The default value is 600. Setting it to 0 disables this feature.



@item pass-discard-request

Whether discard requests to the qcow2 device should be forwarded to the data