From: Baokun Li libaokun1@huawei.com
hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB5UKT
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Make cachefiles support buffer I/O when reading and writing backend files, which reduces the latency of concurrent reads when there is a local cache. This can be useful in container batch recovery scenarios.
arm64 nvme:
ext4 BIO no cache 1399MiB/s, 8t 11.5GiB/s, with cache 1t 1880MiB/s, 8t 12.7GiB/s.
thread|type | cache miss | local cache | erofs pagecache | ------+-----+------------+-------------+-----------------| 1t | DIO | 243 MiB/s | 898 MiB/s | 1907 MiB/s | 1t | BIO | 243 MiB/s | 1147 MiB/s | 1894MiB/s | +27% ------+-----+------------+-------------+-----------------| 8t | DIO | 1950 MiB/s | 5155 MiB/s | 12.8GiB/s | 8t | BIO | 1951 MiB/s | 11.2GiB/s | 12.6GiB/s | +122%
x86 HDD:
ext4 BIO no cache 494MiB/s, 8t 3949MiB/s, with cache 1t 1066MiB/s, 8t 8669MiB/s. thread|type | cache miss | local cache | erofs pagecache | ------+-----+------------+-------------+-----------------| 1t | DIO | 228 MiB/s | 493 MiB/s | 1133 MiB/s | 1t | BIO | 224 MiB/s | 858 MiB/s | 1133 MiB/s | +74% ------+-----+------------+-------------+-----------------| 8t | DIO | 1885 MiB/s | 3893 MiB/s | 8357 MiB/s | 8t | BIO | 1898 MiB/s | 7948 MiB/s | 8357 MiB/s | +104%
The controls are the same as in the lower versions and also affect only the on-demand mode.
Enable: modprobe cachefiles buffered_ondemand=1 echo 1 > /sys/module/cachefiles/parameters/buffered_ondemand
Disable: modprobe cachefiles buffered_ondemand=0 echo 0 > /sys/module/cachefiles/parameters/buffered_ondemand
Signed-off-by: Baokun Li libaokun1@huawei.com Signed-off-by: Zizhi Wo wozizhi@huawei.com --- fs/cachefiles/io.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c index 009d23cd435b..e55c7cc6a997 100644 --- a/fs/cachefiles/io.c +++ b/fs/cachefiles/io.c @@ -12,8 +12,12 @@ #include <linux/falloc.h> #include <linux/sched/mm.h> #include <trace/events/fscache.h> +#include <linux/module.h> #include "internal.h"
+static bool cachefiles_buffered_ondemand = true; +module_param_named(buffered_ondemand, cachefiles_buffered_ondemand, bool, 0644); + struct cachefiles_kiocb { struct kiocb iocb; refcount_t ki_refcnt; @@ -78,6 +82,7 @@ static int cachefiles_read(struct netfs_cache_resources *cres, void *term_func_priv) { struct cachefiles_object *object; + struct cachefiles_cache *cache; struct cachefiles_kiocb *ki; struct file *file; unsigned int old_nofs; @@ -89,6 +94,7 @@ static int cachefiles_read(struct netfs_cache_resources *cres,
fscache_count_read(); object = cachefiles_cres_object(cres); + cache = object->volume->cache; file = cachefiles_cres_file(cres);
_enter("%pD,%li,%llx,%zx/%llx", @@ -146,6 +152,9 @@ static int cachefiles_read(struct netfs_cache_resources *cres, ki->term_func_priv = term_func_priv; ki->was_async = true;
+ if (cachefiles_in_ondemand_mode(cache) && cachefiles_buffered_ondemand) + ki->iocb.ki_flags &= ~IOCB_DIRECT; + if (ki->term_func) ki->iocb.ki_complete = cachefiles_read_complete;
@@ -315,6 +324,9 @@ int __cachefiles_write(struct cachefiles_object *object, ki->was_async = true; ki->b_writing = (len + (1 << cache->bshift) - 1) >> cache->bshift;
+ if (cachefiles_in_ondemand_mode(cache) && cachefiles_buffered_ondemand) + ki->iocb.ki_flags &= ~IOCB_DIRECT; + if (ki->term_func) ki->iocb.ki_complete = cachefiles_write_complete; atomic_long_add(ki->b_writing, &cache->b_writing);