* [PATCH 0/2] xen/blkback: add LRU purge parameters
@ 2020-10-15 14:24 Roger Pau Monne
2020-10-15 14:24 ` [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter Roger Pau Monne
2020-10-15 14:24 ` [PATCH 2/2] xen/blkback: turn the cache purge percent " Roger Pau Monne
0 siblings, 2 replies; 7+ messages in thread
From: Roger Pau Monne @ 2020-10-15 14:24 UTC (permalink / raw)
To: linux-kernel
Cc: Roger Pau Monne, Konrad Rzeszutek Wilk, Jens Axboe,
Boris Ostrovsky, SeongJae Park, xen-devel, linux-block,
Jürgen Groß,
J . Roeleveld
Add the LRU parameters as tunables.
Roger Pau Monne (2):
xen/blkback: turn the cache purge LRU interval into a parameter
xen/blkback: turn the cache purge percent into a parameter
.../ABI/testing/sysfs-driver-xen-blkback | 19 +++++++++++++++++++
drivers/block/xen-blkback/blkback.c | 16 +++++++++++-----
2 files changed, 30 insertions(+), 5 deletions(-)
--
2.28.0
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter
2020-10-15 14:24 [PATCH 0/2] xen/blkback: add LRU purge parameters Roger Pau Monne
@ 2020-10-15 14:24 ` Roger Pau Monne
2020-10-15 14:30 ` Jürgen Groß
2020-10-15 15:08 ` SeongJae Park
2020-10-15 14:24 ` [PATCH 2/2] xen/blkback: turn the cache purge percent " Roger Pau Monne
1 sibling, 2 replies; 7+ messages in thread
From: Roger Pau Monne @ 2020-10-15 14:24 UTC (permalink / raw)
To: linux-kernel
Cc: Roger Pau Monne, Konrad Rzeszutek Wilk, Jens Axboe,
Boris Ostrovsky, SeongJae Park, xen-devel, linux-block,
J . Roeleveld, Jürgen Groß
Assume that reads and writes to the variable will be atomic. The worse
that could happen is that one of the LRU intervals is not calculated
properly if a partially written value is read, but that would only be
a transient issue.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: xen-devel@lists.xenproject.org
Cc: linux-block@vger.kernel.org
Cc: J. Roeleveld <joost@antarean.org>
Cc: Jürgen Groß <jgross@suse.com>
---
Documentation/ABI/testing/sysfs-driver-xen-blkback | 10 ++++++++++
drivers/block/xen-blkback/blkback.c | 9 ++++++---
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback
index ecb7942ff146..776f25d335ca 100644
--- a/Documentation/ABI/testing/sysfs-driver-xen-blkback
+++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback
@@ -35,3 +35,13 @@ Description:
controls the duration in milliseconds that blkback will not
cache any page not backed by a grant mapping.
The default is 10ms.
+
+What: /sys/module/xen_blkback/parameters/lru_internval
+Date: October 2020
+KernelVersion: 5.10
+Contact: Roger Pau Monné <roger.pau@citrix.com>
+Description:
+ The LRU mechanism to clean the lists of persistent grants needs
+ to be executed periodically. This parameter controls the time
+ interval between consecutive executions of the purge mechanism
+ is set in ms.
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index adfc9352351d..6ad9b76fdb2b 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -117,7 +117,10 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the
* be executed periodically. The time interval between consecutive executions
* of the purge mechanism is set in ms.
*/
-#define LRU_INTERVAL 100
+static unsigned int lru_interval = 100;
+module_param_named(lru_interval, lru_interval, uint, 0644);
+MODULE_PARM_DESC(lru_internval,
+ "Time interval between consecutive executions of the cache purge mechanism (in ms)");
/*
* When the persistent grants list is full we will remove unused grants
@@ -620,7 +623,7 @@ int xen_blkif_schedule(void *arg)
if (unlikely(vbd->size != vbd_sz(vbd)))
xen_vbd_resize(blkif);
- timeout = msecs_to_jiffies(LRU_INTERVAL);
+ timeout = msecs_to_jiffies(lru_interval);
timeout = wait_event_interruptible_timeout(
ring->wq,
@@ -650,7 +653,7 @@ int xen_blkif_schedule(void *arg)
if (blkif->vbd.feature_gnt_persistent &&
time_after(jiffies, ring->next_lru)) {
purge_persistent_gnt(ring);
- ring->next_lru = jiffies + msecs_to_jiffies(LRU_INTERVAL);
+ ring->next_lru = jiffies + msecs_to_jiffies(lru_interval);
}
/* Shrink the free pages pool if it is too large. */
--
2.28.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 2/2] xen/blkback: turn the cache purge percent into a parameter
2020-10-15 14:24 [PATCH 0/2] xen/blkback: add LRU purge parameters Roger Pau Monne
2020-10-15 14:24 ` [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter Roger Pau Monne
@ 2020-10-15 14:24 ` Roger Pau Monne
2020-10-15 14:37 ` Jürgen Groß
1 sibling, 1 reply; 7+ messages in thread
From: Roger Pau Monne @ 2020-10-15 14:24 UTC (permalink / raw)
To: linux-kernel
Cc: Roger Pau Monne, Konrad Rzeszutek Wilk, Jens Axboe,
Boris Ostrovsky, SeongJae Park, xen-devel, linux-block,
J . Roeleveld, Jürgen Groß
Assume that reads and writes to the variable will be atomic. The worse
that could happen is that one of the purges removes a partially
written percentage of grants, but the cache itself will recover.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: xen-devel@lists.xenproject.org
Cc: linux-block@vger.kernel.org
Cc: J. Roeleveld <joost@antarean.org>
Cc: Jürgen Groß <jgross@suse.com>
---
Documentation/ABI/testing/sysfs-driver-xen-blkback | 9 +++++++++
drivers/block/xen-blkback/blkback.c | 7 +++++--
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback
index 776f25d335ca..7de791ad61f9 100644
--- a/Documentation/ABI/testing/sysfs-driver-xen-blkback
+++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback
@@ -45,3 +45,12 @@ Description:
to be executed periodically. This parameter controls the time
interval between consecutive executions of the purge mechanism
is set in ms.
+
+What: /sys/module/xen_blkback/parameters/lru_percent_clean
+Date: October 2020
+KernelVersion: 5.10
+Contact: Roger Pau Monné <roger.pau@citrix.com>
+Description:
+ When the persistent grants list is full we will remove unused
+ grants from the list. The percent number of grants to be
+ removed at each LRU execution.
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 6ad9b76fdb2b..772852d45a5a 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -127,7 +127,10 @@ MODULE_PARM_DESC(lru_internval,
* from the list. The percent number of grants to be removed at each LRU
* execution.
*/
-#define LRU_PERCENT_CLEAN 5
+static unsigned int lru_percent_clean = 5;
+module_param_named(lru_percent_clean, lru_percent_clean, uint, 0644);
+MODULE_PARM_DESC(lru_percent_clean,
+ "Percentage of persistent grants to remove from the cache when full");
/* Run-time switchable: /sys/module/blkback/parameters/ */
static unsigned int log_stats;
@@ -404,7 +407,7 @@ static void purge_persistent_gnt(struct xen_blkif_ring *ring)
!ring->blkif->vbd.overflow_max_grants)) {
num_clean = 0;
} else {
- num_clean = (max_pgrants / 100) * LRU_PERCENT_CLEAN;
+ num_clean = (max_pgrants / 100) * lru_percent_clean;
num_clean = ring->persistent_gnt_c - max_pgrants + num_clean;
num_clean = min(ring->persistent_gnt_c, num_clean);
pr_debug("Going to purge at least %u persistent grants\n",
--
2.28.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter
2020-10-15 14:24 ` [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter Roger Pau Monne
@ 2020-10-15 14:30 ` Jürgen Groß
2020-10-15 15:08 ` SeongJae Park
1 sibling, 0 replies; 7+ messages in thread
From: Jürgen Groß @ 2020-10-15 14:30 UTC (permalink / raw)
To: Roger Pau Monne, linux-kernel
Cc: Konrad Rzeszutek Wilk, Jens Axboe, Boris Ostrovsky,
SeongJae Park, xen-devel, linux-block, J . Roeleveld
On 15.10.20 16:24, Roger Pau Monne wrote:
> Assume that reads and writes to the variable will be atomic. The worse
> that could happen is that one of the LRU intervals is not calculated
> properly if a partially written value is read, but that would only be
> a transient issue.
>
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> ---
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: SeongJae Park <sjpark@amazon.de>
> Cc: xen-devel@lists.xenproject.org
> Cc: linux-block@vger.kernel.org
> Cc: J. Roeleveld <joost@antarean.org>
> Cc: Jürgen Groß <jgross@suse.com>
> ---
> Documentation/ABI/testing/sysfs-driver-xen-blkback | 10 ++++++++++
> drivers/block/xen-blkback/blkback.c | 9 ++++++---
> 2 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback
> index ecb7942ff146..776f25d335ca 100644
> --- a/Documentation/ABI/testing/sysfs-driver-xen-blkback
> +++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback
> @@ -35,3 +35,13 @@ Description:
> controls the duration in milliseconds that blkback will not
> cache any page not backed by a grant mapping.
> The default is 10ms.
> +
> +What: /sys/module/xen_blkback/parameters/lru_internval
s/lru_internval/lru_interval/
> +Date: October 2020
> +KernelVersion: 5.10
> +Contact: Roger Pau Monné <roger.pau@citrix.com>
> +Description:
> + The LRU mechanism to clean the lists of persistent grants needs
> + to be executed periodically. This parameter controls the time
> + interval between consecutive executions of the purge mechanism
> + is set in ms.
> diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
> index adfc9352351d..6ad9b76fdb2b 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -117,7 +117,10 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the
> * be executed periodically. The time interval between consecutive executions
> * of the purge mechanism is set in ms.
> */
> -#define LRU_INTERVAL 100
> +static unsigned int lru_interval = 100;
> +module_param_named(lru_interval, lru_interval, uint, 0644);
> +MODULE_PARM_DESC(lru_internval,
s/lru_internval/lru_interval/
> + "Time interval between consecutive executions of the cache purge mechanism (in ms)");
>
> /*
> * When the persistent grants list is full we will remove unused grants
> @@ -620,7 +623,7 @@ int xen_blkif_schedule(void *arg)
> if (unlikely(vbd->size != vbd_sz(vbd)))
> xen_vbd_resize(blkif);
>
> - timeout = msecs_to_jiffies(LRU_INTERVAL);
> + timeout = msecs_to_jiffies(lru_interval);
>
> timeout = wait_event_interruptible_timeout(
> ring->wq,
> @@ -650,7 +653,7 @@ int xen_blkif_schedule(void *arg)
> if (blkif->vbd.feature_gnt_persistent &&
> time_after(jiffies, ring->next_lru)) {
> purge_persistent_gnt(ring);
> - ring->next_lru = jiffies + msecs_to_jiffies(LRU_INTERVAL);
> + ring->next_lru = jiffies + msecs_to_jiffies(lru_interval);
> }
>
> /* Shrink the free pages pool if it is too large. */
>
Juergen
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/2] xen/blkback: turn the cache purge percent into a parameter
2020-10-15 14:24 ` [PATCH 2/2] xen/blkback: turn the cache purge percent " Roger Pau Monne
@ 2020-10-15 14:37 ` Jürgen Groß
2020-10-15 14:44 ` Roger Pau Monné
0 siblings, 1 reply; 7+ messages in thread
From: Jürgen Groß @ 2020-10-15 14:37 UTC (permalink / raw)
To: Roger Pau Monne, linux-kernel
Cc: Konrad Rzeszutek Wilk, Jens Axboe, Boris Ostrovsky,
SeongJae Park, xen-devel, linux-block, J . Roeleveld
On 15.10.20 16:24, Roger Pau Monne wrote:
> Assume that reads and writes to the variable will be atomic. The worse
> that could happen is that one of the purges removes a partially
> written percentage of grants, but the cache itself will recover.
>
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> ---
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: SeongJae Park <sjpark@amazon.de>
> Cc: xen-devel@lists.xenproject.org
> Cc: linux-block@vger.kernel.org
> Cc: J. Roeleveld <joost@antarean.org>
> Cc: Jürgen Groß <jgross@suse.com>
> ---
> Documentation/ABI/testing/sysfs-driver-xen-blkback | 9 +++++++++
> drivers/block/xen-blkback/blkback.c | 7 +++++--
> 2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback
> index 776f25d335ca..7de791ad61f9 100644
> --- a/Documentation/ABI/testing/sysfs-driver-xen-blkback
> +++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback
> @@ -45,3 +45,12 @@ Description:
> to be executed periodically. This parameter controls the time
> interval between consecutive executions of the purge mechanism
> is set in ms.
> +
> +What: /sys/module/xen_blkback/parameters/lru_percent_clean
> +Date: October 2020
> +KernelVersion: 5.10
> +Contact: Roger Pau Monné <roger.pau@citrix.com>
> +Description:
> + When the persistent grants list is full we will remove unused
> + grants from the list. The percent number of grants to be
> + removed at each LRU execution.
> diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
> index 6ad9b76fdb2b..772852d45a5a 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -127,7 +127,10 @@ MODULE_PARM_DESC(lru_internval,
> * from the list. The percent number of grants to be removed at each LRU
> * execution.
> */
> -#define LRU_PERCENT_CLEAN 5
> +static unsigned int lru_percent_clean = 5;
> +module_param_named(lru_percent_clean, lru_percent_clean, uint, 0644);
> +MODULE_PARM_DESC(lru_percent_clean,
> + "Percentage of persistent grants to remove from the cache when full");
>
> /* Run-time switchable: /sys/module/blkback/parameters/ */
> static unsigned int log_stats;
> @@ -404,7 +407,7 @@ static void purge_persistent_gnt(struct xen_blkif_ring *ring)
> !ring->blkif->vbd.overflow_max_grants)) {
> num_clean = 0;
> } else {
> - num_clean = (max_pgrants / 100) * LRU_PERCENT_CLEAN;
> + num_clean = (max_pgrants / 100) * lru_percent_clean;
Hmm, wouldn't it be better to use (max_grants * lru_percent_clean) / 100
here in order to support max_grants values less than 100?
Juergen
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/2] xen/blkback: turn the cache purge percent into a parameter
2020-10-15 14:37 ` Jürgen Groß
@ 2020-10-15 14:44 ` Roger Pau Monné
0 siblings, 0 replies; 7+ messages in thread
From: Roger Pau Monné @ 2020-10-15 14:44 UTC (permalink / raw)
To: Jürgen Groß
Cc: linux-kernel, Konrad Rzeszutek Wilk, Jens Axboe, Boris Ostrovsky,
SeongJae Park, xen-devel, linux-block, J . Roeleveld
On Thu, Oct 15, 2020 at 04:37:52PM +0200, Jürgen Groß wrote:
> On 15.10.20 16:24, Roger Pau Monne wrote:
> > Assume that reads and writes to the variable will be atomic. The worse
> > that could happen is that one of the purges removes a partially
> > written percentage of grants, but the cache itself will recover.
> >
> > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> > ---
> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > Cc: Jens Axboe <axboe@kernel.dk>
> > Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> > Cc: SeongJae Park <sjpark@amazon.de>
> > Cc: xen-devel@lists.xenproject.org
> > Cc: linux-block@vger.kernel.org
> > Cc: J. Roeleveld <joost@antarean.org>
> > Cc: Jürgen Groß <jgross@suse.com>
> > ---
> > Documentation/ABI/testing/sysfs-driver-xen-blkback | 9 +++++++++
> > drivers/block/xen-blkback/blkback.c | 7 +++++--
> > 2 files changed, 14 insertions(+), 2 deletions(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback
> > index 776f25d335ca..7de791ad61f9 100644
> > --- a/Documentation/ABI/testing/sysfs-driver-xen-blkback
> > +++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback
> > @@ -45,3 +45,12 @@ Description:
> > to be executed periodically. This parameter controls the time
> > interval between consecutive executions of the purge mechanism
> > is set in ms.
> > +
> > +What: /sys/module/xen_blkback/parameters/lru_percent_clean
> > +Date: October 2020
> > +KernelVersion: 5.10
> > +Contact: Roger Pau Monné <roger.pau@citrix.com>
> > +Description:
> > + When the persistent grants list is full we will remove unused
> > + grants from the list. The percent number of grants to be
> > + removed at each LRU execution.
> > diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
> > index 6ad9b76fdb2b..772852d45a5a 100644
> > --- a/drivers/block/xen-blkback/blkback.c
> > +++ b/drivers/block/xen-blkback/blkback.c
> > @@ -127,7 +127,10 @@ MODULE_PARM_DESC(lru_internval,
> > * from the list. The percent number of grants to be removed at each LRU
> > * execution.
> > */
> > -#define LRU_PERCENT_CLEAN 5
> > +static unsigned int lru_percent_clean = 5;
> > +module_param_named(lru_percent_clean, lru_percent_clean, uint, 0644);
> > +MODULE_PARM_DESC(lru_percent_clean,
> > + "Percentage of persistent grants to remove from the cache when full");
> > /* Run-time switchable: /sys/module/blkback/parameters/ */
> > static unsigned int log_stats;
> > @@ -404,7 +407,7 @@ static void purge_persistent_gnt(struct xen_blkif_ring *ring)
> > !ring->blkif->vbd.overflow_max_grants)) {
> > num_clean = 0;
> > } else {
> > - num_clean = (max_pgrants / 100) * LRU_PERCENT_CLEAN;
> > + num_clean = (max_pgrants / 100) * lru_percent_clean;
>
> Hmm, wouldn't it be better to use (max_grants * lru_percent_clean) / 100
> here in order to support max_grants values less than 100?
Yes, we should have done that when moving max_pgrants to a parameter,
it used to be fixed first.
Will do in next version since I'm already changing the line.
Thanks, Roger.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter
2020-10-15 14:24 ` [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter Roger Pau Monne
2020-10-15 14:30 ` Jürgen Groß
@ 2020-10-15 15:08 ` SeongJae Park
1 sibling, 0 replies; 7+ messages in thread
From: SeongJae Park @ 2020-10-15 15:08 UTC (permalink / raw)
To: Roger Pau Monne
Cc: linux-kernel, Konrad Rzeszutek Wilk, Jens Axboe, Boris Ostrovsky,
SeongJae Park, xen-devel, linux-block, J . Roeleveld,
Jürgen Groß
On Thu, 15 Oct 2020 16:24:15 +0200 Roger Pau Monne <roger.pau@citrix.com> wrote:
> Assume that reads and writes to the variable will be atomic. The worse
> that could happen is that one of the LRU intervals is not calculated
> properly if a partially written value is read, but that would only be
> a transient issue.
>
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> ---
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: SeongJae Park <sjpark@amazon.de>
> Cc: xen-devel@lists.xenproject.org
> Cc: linux-block@vger.kernel.org
> Cc: J. Roeleveld <joost@antarean.org>
> Cc: Jürgen Groß <jgross@suse.com>
> ---
> Documentation/ABI/testing/sysfs-driver-xen-blkback | 10 ++++++++++
> drivers/block/xen-blkback/blkback.c | 9 ++++++---
> 2 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback
> index ecb7942ff146..776f25d335ca 100644
> --- a/Documentation/ABI/testing/sysfs-driver-xen-blkback
> +++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback
> @@ -35,3 +35,13 @@ Description:
> controls the duration in milliseconds that blkback will not
> cache any page not backed by a grant mapping.
> The default is 10ms.
> +
> +What: /sys/module/xen_blkback/parameters/lru_internval
> +Date: October 2020
> +KernelVersion: 5.10
> +Contact: Roger Pau Monné <roger.pau@citrix.com>
> +Description:
> + The LRU mechanism to clean the lists of persistent grants needs
> + to be executed periodically. This parameter controls the time
> + interval between consecutive executions of the purge mechanism
> + is set in ms.
I think noticing the default value (100ms) here would be better.
Thanks,
SeongJae Park
^ permalink raw reply [flat|nested] 7+ messages in thread
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2020-10-15 14:24 [PATCH 0/2] xen/blkback: add LRU purge parameters Roger Pau Monne
2020-10-15 14:24 ` [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter Roger Pau Monne
2020-10-15 14:30 ` Jürgen Groß
2020-10-15 15:08 ` SeongJae Park
2020-10-15 14:24 ` [PATCH 2/2] xen/blkback: turn the cache purge percent " Roger Pau Monne
2020-10-15 14:37 ` Jürgen Groß
2020-10-15 14:44 ` Roger Pau Monné
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