search for: lru_set_size

...ISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef NBDKIT_LRU_H +#define NBDKIT_LRU_H + +#include <stdbool.h> + +/* Initialize LRU. */ +extern void lru_init (void); + +/* Free the LRU. */ +extern void lru_free (void); + +/* Notify LRU that the virtual size has changed. */ +extern int lru_set_size (uint64_t new_size); + +/* Mark a block as recently accessed in the LRU structure. */ +extern void lru_set_recently_accessed (uint64_t blknum); + +/* Check if a block has been recently accessed. */ +extern bool lru_has_been_recently_accessed (uint64_t blknum); + +#endif /* NBDKIT_LRU_H */ diff --gi...

...ISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef NBDKIT_LRU_H +#define NBDKIT_LRU_H + +#include <stdbool.h> + +/* Initialize LRU. */ +extern void lru_init (void); + +/* Free the LRU. */ +extern void lru_free (void); + +/* Notify LRU that the virtual size has changed. */ +extern int lru_set_size (uint64_t new_size); + +/* Mark a block as recently accessed in the LRU structure. */ +extern void lru_set_recently_accessed (uint64_t blknum); + +/* Check if a block has been recently accessed. */ +extern bool lru_has_been_recently_accessed (uint64_t blknum); + +#endif /* NBDKIT_LRU_H */ diff --gi...

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.

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

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.

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.

...= cache_config_complete, .open = cache_open, .prepare = cache_prepare, .get_size = cache_get_size, diff --git a/filters/cache/lru.c b/filters/cache/lru.c index 60cf379..8159040 100644 --- a/filters/cache/lru.c +++ b/filters/cache/lru.c @@ -109,8 +109,11 @@ lru_set_size (uint64_t new_size) if (bitmap_resize (&bm[1], new_size) == -1) return -1; - /* XXX Choose this better. */ - N = MAX (new_size / BLKSIZE / 4, 100); + if (max_size != -1) + /* Make the threshold about 1/4 the maximum size of the cache. */ + N = MAX (max_size / BLKSIZE / 4, 100...

...= cache_config_complete, .open = cache_open, .prepare = cache_prepare, .get_size = cache_get_size, diff --git a/filters/cache/lru.c b/filters/cache/lru.c index 60cf379..8159040 100644 --- a/filters/cache/lru.c +++ b/filters/cache/lru.c @@ -109,8 +109,11 @@ lru_set_size (uint64_t new_size) if (bitmap_resize (&bm[1], new_size) == -1) return -1; - /* XXX Choose this better. */ - N = MAX (new_size / BLKSIZE / 4, 100); + if (max_size != -1) + /* Make the threshold about 1/4 the maximum size of the cache. */ + N = MAX (max_size / BLKSIZE / 4, 100...

...crement c0 (c0 counts the number of bits set in bm[0]). If + * c0 == N/2 then we swap the two bitmaps, clear bm[0], and reset c0 + * to 0. * * To check if a block has been accessed within the previous N * distinct accesses, we simply have to check both bitmaps. If it is @@ -109,8 +110,11 @@ lru_set_size (uint64_t new_size) if (bitmap_resize (&bm[1], new_size) == -1) return -1; - /* XXX Choose this better. */ - N = MAX (new_size / BLKSIZE / 4, 100); + if (max_size != -1) + /* Make the threshold about 1/4 the maximum size of the cache. */ + N = MAX (max_size / BLKSIZE / 4, 100...

...= cache_config_complete, .open = cache_open, .prepare = cache_prepare, .get_size = cache_get_size, diff --git a/filters/cache/lru.c b/filters/cache/lru.c index c828968..2f379d1 100644 --- a/filters/cache/lru.c +++ b/filters/cache/lru.c @@ -110,8 +110,11 @@ lru_set_size (uint64_t new_size) if (bitmap_resize (&bm[1], new_size) == -1) return -1; - /* XXX Choose this better. */ - N = MAX (new_size / BLKSIZE / 4, 100); + if (max_size != -1) + /* Make the threshold about 1/4 the maximum size of the cache. */ + N = MAX (max_size / BLKSIZE / 4, 100...

...lru_init (void) { - bitmap_init (&bm[0], BLKSIZE, 1 /* bits per block */); - bitmap_init (&bm[1], BLKSIZE, 1 /* bits per block */); + bitmap_init (&bm[0], blksize, 1 /* bits per block */); + bitmap_init (&bm[1], blksize, 1 /* bits per block */); } void @@ -109,8 +109,11 @@ lru_set_size (uint64_t new_size) if (bitmap_resize (&bm[1], new_size) == -1) return -1; - /* XXX Choose this better. */ - N = MAX (new_size / BLKSIZE / 4, 100); + if (max_size != -1) + /* Make the threshold about 1/4 the maximum size of the cache. */ + N = MAX (max_size / blksize / 4, 100...