search for: have_cache_reclaim

...s, like 90.5, or must they be integral? Should we enforce that low threshold < high threshold? What does it really mean to have a threshold > 100 - that we can never reach the high threshold? > +/* Do we support reclaiming cache blocks? */ > +#ifdef FALLOC_FL_PUNCH_HOLE > +#define HAVE_CACHE_RECLAIM 1 > +#else > +#undef HAVE_CACHE_RECLAIM > +#endif > + Should the man page mention that max cache size can only be enforced with kernel support? Do we want to go further and probe whether FALLOC_FL_PUNCH_HOLE works on $TMPDIR? (Even if the kernel supports punching holes, there are som...

...CACHE_MODE_UNSAFE, } cache_mode; +/* Maximum size of the cache and high/low thresholds. */ +extern int64_t max_size; +extern int hi_thresh, lo_thresh; + /* Cache read requests. */ extern bool cache_on_read; +/* Do we support reclaiming cache blocks? */ +#ifdef FALLOC_FL_PUNCH_HOLE +#define HAVE_CACHE_RECLAIM 1 +#else +#undef HAVE_CACHE_RECLAIM +#endif + #endif /* NBDKIT_CACHE_H */ diff --git a/filters/cache/blk.c b/filters/cache/blk.c index b256446..294f0cb 100644 --- a/filters/cache/blk.c +++ b/filters/cache/blk.c @@ -46,6 +46,8 @@ #include <unistd.h> #include <fcntl.h> #include <er...

...CACHE_MODE_UNSAFE, } cache_mode; +/* Maximum size of the cache and high/low thresholds. */ +extern int64_t max_size; +extern int hi_thresh, lo_thresh; + /* Cache read requests. */ extern bool cache_on_read; +/* Do we support reclaiming cache blocks? */ +#ifdef FALLOC_FL_PUNCH_HOLE +#define HAVE_CACHE_RECLAIM 1 +#else +#undef HAVE_CACHE_RECLAIM +#endif + #endif /* NBDKIT_CACHE_H */ diff --git a/filters/cache/blk.c b/filters/cache/blk.c index b256446..4a7f65f 100644 --- a/filters/cache/blk.c +++ b/filters/cache/blk.c @@ -46,6 +46,8 @@ #include <unistd.h> #include <fcntl.h> #include <er...

...CACHE_MODE_UNSAFE, } cache_mode; +/* Maximum size of the cache and high/low thresholds. */ +extern int64_t max_size; +extern int hi_thresh, lo_thresh; + /* Cache read requests. */ extern bool cache_on_read; +/* Do we support reclaiming cache blocks? */ +#ifdef FALLOC_FL_PUNCH_HOLE +#define HAVE_CACHE_RECLAIM 1 +#else +#undef HAVE_CACHE_RECLAIM +#endif + #endif /* NBDKIT_CACHE_H */ diff --git a/filters/cache/blk.c b/filters/cache/blk.c index b256446..6f67a7f 100644 --- a/filters/cache/blk.c +++ b/filters/cache/blk.c @@ -46,6 +46,8 @@ #include <unistd.h> #include <fcntl.h> #include <er...

...OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef NBDKIT_RECLAIM_H +#define NBDKIT_RECLAIM_H + +#include "bitmap.h" + +/* Do we support reclaiming cache blocks? */ +#ifdef FALLOC_FL_PUNCH_HOLE +#define HAVE_CACHE_RECLAIM 1 +#else +#undef HAVE_CACHE_RECLAIM +#endif + +extern void reclaim (int fd, struct bitmap *bm); + +#endif /* NBDKIT_RECLAIM_H */ diff --git a/filters/cache/blk.c b/filters/cache/blk.c index b256446..028eedb 100644 --- a/filters/cache/blk.c +++ b/filters/cache/blk.c @@ -54,6 +54,7 @@ #include &quot...

Patch 1 is the same as last time, except for a minor comment fix. Patch 2 should address everything that Eric mentioned in his review, and has been retested. Rich.

These are essentially identical to what was previously posted as patches 6/9 through 9/9 here: https://www.redhat.com/archives/libguestfs/2018-December/msg00145.html except that it has been rebased onto the current git master and retested thoroughly. Rich.

...OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef NBDKIT_RECLAIM_H +#define NBDKIT_RECLAIM_H + +#include "bitmap.h" + +/* Do we support reclaiming cache blocks? */ +#ifdef FALLOC_FL_PUNCH_HOLE +#define HAVE_CACHE_RECLAIM 1 +#else +#undef HAVE_CACHE_RECLAIM +#endif + +/* Check if we need to reclaim blocks, and if so reclaim up to two + * blocks. + * + * Note this must be called with the blk lock held. + */ +extern void reclaim (int fd, struct bitmap *bm); + +#endif /* NBDKIT_RECLAIM_H */ diff --git a/filters/cache/b...

v3 was broken by a bad rebase, so let's forget about that one. Compared to v2: - Patch 1 is the same except for a minor comment change. - Patch 2 splits the reclaim code into a separate file (filters/cache/reclaim.c) - Addressed Eric's comments from his review of v2. - Retested on Linux and FreeBSD.

v4: https://www.redhat.com/archives/libguestfs/2019-January/msg00032.html v5: - Now we set the block size at run time. I'd like to say that I was able to test this change, but unfortunately I couldn't find any easy way to create a filesystem on x86-64 with a block size > 4K. Ext4 doesn't support it at all, and XFS doesn't support block size > page size (and I

This patch series enhances the cache filter in a few ways, primarily adding a "cache-on-read" feature (similar to qemu's copyonread); and adding the ability to limit the cache size and the antecedent of that which is having a method to reclaim cache blocks. As the cache is stored as a sparse temporary file, reclaiming cache blocks simply means punching holes in the temporary file.