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authorSergey Senozhatsky <sergey.senozhatsky@gmail.com>2014-04-07 15:38:15 -0700
committerAlex Shi <alex.shi@linaro.org>2015-05-11 20:43:28 +0800
commit9634c9a147869de6d78f53a49823980aaea7233c (patch)
treee8db8215474686c2ce987ce3b52dbcb0f2527256 /drivers
parentde980e9147bd30182894d0bb6778fbd0c8a7f293 (diff)
downloadlinux-linaro-stable-9634c9a147869de6d78f53a49823980aaea7233c.tar.gz
zram: add set_max_streams knob
This patch allows to change max_comp_streams on initialised zcomp. Introduce zcomp set_max_streams() knob, zcomp_strm_multi_set_max_streams() and zcomp_strm_single_set_max_streams() callbacks to change streams limit for zcomp_strm_multi and zcomp_strm_single, accordingly. set_max_streams for single steam zcomp does nothing. If user has lowered the limit, then zcomp_strm_multi_set_max_streams() attempts to immediately free extra streams (as much as it can, depending on idle streams availability). Note, this patch does not allow to change stream 'policy' from single to multi stream (or vice versa) on already initialised compression backend. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit fe8eb122c82b2049c460fc6df6e8583a2f935cff) Signed-off-by: Alex Shi <alex.shi@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/zram/zcomp.c36
-rw-r--r--drivers/block/zram/zcomp.h3
-rw-r--r--drivers/block/zram/zram_drv.c5
3 files changed, 41 insertions, 3 deletions
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index c06f75f54718..ac276f79f21c 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -136,6 +136,29 @@ static void zcomp_strm_multi_release(struct zcomp *comp, struct zcomp_strm *zstr
zcomp_strm_free(comp, zstrm);
}
+/* change max_strm limit */
+static int zcomp_strm_multi_set_max_streams(struct zcomp *comp, int num_strm)
+{
+ struct zcomp_strm_multi *zs = comp->stream;
+ struct zcomp_strm *zstrm;
+
+ spin_lock(&zs->strm_lock);
+ zs->max_strm = num_strm;
+ /*
+ * if user has lowered the limit and there are idle streams,
+ * immediately free as much streams (and memory) as we can.
+ */
+ while (zs->avail_strm > num_strm && !list_empty(&zs->idle_strm)) {
+ zstrm = list_entry(zs->idle_strm.next,
+ struct zcomp_strm, list);
+ list_del(&zstrm->list);
+ zcomp_strm_free(comp, zstrm);
+ zs->avail_strm--;
+ }
+ spin_unlock(&zs->strm_lock);
+ return 0;
+}
+
static void zcomp_strm_multi_destroy(struct zcomp *comp)
{
struct zcomp_strm_multi *zs = comp->stream;
@@ -158,6 +181,7 @@ static int zcomp_strm_multi_create(struct zcomp *comp, int max_strm)
comp->destroy = zcomp_strm_multi_destroy;
comp->strm_find = zcomp_strm_multi_find;
comp->strm_release = zcomp_strm_multi_release;
+ comp->set_max_streams = zcomp_strm_multi_set_max_streams;
zs = kmalloc(sizeof(struct zcomp_strm_multi), GFP_KERNEL);
if (!zs)
return -ENOMEM;
@@ -192,6 +216,12 @@ static void zcomp_strm_single_release(struct zcomp *comp,
mutex_unlock(&zs->strm_lock);
}
+static int zcomp_strm_single_set_max_streams(struct zcomp *comp, int num_strm)
+{
+ /* zcomp_strm_single support only max_comp_streams == 1 */
+ return -ENOTSUPP;
+}
+
static void zcomp_strm_single_destroy(struct zcomp *comp)
{
struct zcomp_strm_single *zs = comp->stream;
@@ -206,6 +236,7 @@ static int zcomp_strm_single_create(struct zcomp *comp)
comp->destroy = zcomp_strm_single_destroy;
comp->strm_find = zcomp_strm_single_find;
comp->strm_release = zcomp_strm_single_release;
+ comp->set_max_streams = zcomp_strm_single_set_max_streams;
zs = kmalloc(sizeof(struct zcomp_strm_single), GFP_KERNEL);
if (!zs)
return -ENOMEM;
@@ -220,6 +251,11 @@ static int zcomp_strm_single_create(struct zcomp *comp)
return 0;
}
+int zcomp_set_max_streams(struct zcomp *comp, int num_strm)
+{
+ return comp->set_max_streams(comp, num_strm);
+}
+
struct zcomp_strm *zcomp_strm_find(struct zcomp *comp)
{
return comp->strm_find(comp);
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 2a3684446160..bd11d59c5dd1 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -46,6 +46,7 @@ struct zcomp {
struct zcomp_strm *(*strm_find)(struct zcomp *comp);
void (*strm_release)(struct zcomp *comp, struct zcomp_strm *zstrm);
+ int (*set_max_streams)(struct zcomp *comp, int num_strm);
void (*destroy)(struct zcomp *comp);
};
@@ -60,4 +61,6 @@ int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
size_t src_len, unsigned char *dst);
+
+int zcomp_set_max_streams(struct zcomp *comp, int num_strm);
#endif /* _ZCOMP_H_ */
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 88ee317ce6d2..c03d0053309b 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -133,9 +133,8 @@ static ssize_t max_comp_streams_store(struct device *dev,
return -EINVAL;
down_write(&zram->init_lock);
if (init_done(zram)) {
- up_write(&zram->init_lock);
- pr_info("Can't set max_comp_streams for initialized device\n");
- return -EBUSY;
+ if (zcomp_set_max_streams(zram->comp, num))
+ pr_info("Cannot change max compression streams\n");
}
zram->max_comp_streams = num;
up_write(&zram->init_lock);