Gather statistics from the netfs interface that can be exported through a
seqfile.  This is intended to be called by a later patch when viewing
/proc/fs/fscache/stats.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-mm@kvack.org
cc: linux-cachefs@redhat.com
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/161118139247.1232039.10556850937548511068.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161034669.2537118.2761232524997091480.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340397101.1303470.17581910581108378458.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539539959.286939.6794352576462965914.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653797700.2770958.5801990354413178228.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789079281.6155.17141344853277186500.stgit@warthog.procyon.org.uk/ # v6
This commit is contained in:
David Howells 2020-11-03 11:32:41 +00:00
Родитель 77b4d2c631
Коммит 289af54cc6
6 изменённых файлов: 128 добавлений и 2 удалений

Просмотреть файл

@ -6,3 +6,18 @@ config NETFS_SUPPORT
This option enables support for network filesystems, including
helpers for high-level buffered I/O, abstracting out read
segmentation, local caching and transparent huge page support.
config NETFS_STATS
bool "Gather statistical information on local caching"
depends on NETFS_SUPPORT && PROC_FS
help
This option causes statistical information to be gathered on local
caching and exported through file:
/proc/fs/fscache/stats
The gathering of statistics adds a certain amount of overhead to
execution as there are a quite a few stats gathered, and on a
multi-CPU system these may be on cachelines that keep bouncing
between CPUs. On the other hand, the stats are very useful for
debugging purposes. Saying 'Y' here is recommended.

Просмотреть файл

@ -1,6 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
netfs-y := \
read_helper.o
netfs-y := read_helper.o stats.o
obj-$(CONFIG_NETFS_SUPPORT) := netfs.o

Просмотреть файл

@ -16,8 +16,42 @@
*/
extern unsigned int netfs_debug;
/*
* stats.c
*/
#ifdef CONFIG_NETFS_STATS
extern atomic_t netfs_n_rh_readahead;
extern atomic_t netfs_n_rh_readpage;
extern atomic_t netfs_n_rh_rreq;
extern atomic_t netfs_n_rh_sreq;
extern atomic_t netfs_n_rh_download;
extern atomic_t netfs_n_rh_download_done;
extern atomic_t netfs_n_rh_download_failed;
extern atomic_t netfs_n_rh_download_instead;
extern atomic_t netfs_n_rh_read;
extern atomic_t netfs_n_rh_read_done;
extern atomic_t netfs_n_rh_read_failed;
extern atomic_t netfs_n_rh_zero;
extern atomic_t netfs_n_rh_short_read;
extern atomic_t netfs_n_rh_write;
extern atomic_t netfs_n_rh_write_done;
extern atomic_t netfs_n_rh_write_failed;
static inline void netfs_stat(atomic_t *stat)
{
atomic_inc(stat);
}
static inline void netfs_stat_d(atomic_t *stat)
{
atomic_dec(stat);
}
#else
#define netfs_stat(x) do {} while(0)
#define netfs_stat_d(x) do {} while(0)
#endif
/*****************************************************************************/
/*

Просмотреть файл

@ -56,6 +56,7 @@ static struct netfs_read_request *netfs_alloc_read_request(
refcount_set(&rreq->usage, 1);
__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
ops->init_rreq(rreq, file);
netfs_stat(&netfs_n_rh_rreq);
}
return rreq;
@ -88,6 +89,7 @@ static void netfs_free_read_request(struct work_struct *work)
rreq->netfs_ops->cleanup(rreq->mapping, rreq->netfs_priv);
trace_netfs_rreq(rreq, netfs_rreq_trace_free);
kfree(rreq);
netfs_stat_d(&netfs_n_rh_rreq);
}
static void netfs_put_read_request(struct netfs_read_request *rreq, bool was_async)
@ -117,6 +119,7 @@ static struct netfs_read_subrequest *netfs_alloc_subrequest(
refcount_set(&subreq->usage, 2);
subreq->rreq = rreq;
netfs_get_read_request(rreq);
netfs_stat(&netfs_n_rh_sreq);
}
return subreq;
@ -134,6 +137,7 @@ static void __netfs_put_subrequest(struct netfs_read_subrequest *subreq,
trace_netfs_sreq(subreq, netfs_sreq_trace_free);
kfree(subreq);
netfs_stat_d(&netfs_n_rh_sreq);
netfs_put_read_request(rreq, was_async);
}
@ -156,6 +160,7 @@ static void netfs_clear_unread(struct netfs_read_subrequest *subreq)
static void netfs_fill_with_zeroes(struct netfs_read_request *rreq,
struct netfs_read_subrequest *subreq)
{
netfs_stat(&netfs_n_rh_zero);
__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
netfs_subreq_terminated(subreq, 0, false);
}
@ -179,6 +184,7 @@ static void netfs_fill_with_zeroes(struct netfs_read_request *rreq,
static void netfs_read_from_server(struct netfs_read_request *rreq,
struct netfs_read_subrequest *subreq)
{
netfs_stat(&netfs_n_rh_download);
rreq->netfs_ops->issue_op(subreq);
}
@ -288,6 +294,7 @@ static void netfs_rreq_short_read(struct netfs_read_request *rreq,
__clear_bit(NETFS_SREQ_SHORT_READ, &subreq->flags);
__set_bit(NETFS_SREQ_SEEK_DATA_READ, &subreq->flags);
netfs_stat(&netfs_n_rh_short_read);
trace_netfs_sreq(subreq, netfs_sreq_trace_resubmit_short);
netfs_get_read_subrequest(subreq);
@ -319,6 +326,7 @@ static bool netfs_rreq_perform_resubmissions(struct netfs_read_request *rreq)
break;
subreq->source = NETFS_DOWNLOAD_FROM_SERVER;
subreq->error = 0;
netfs_stat(&netfs_n_rh_download_instead);
trace_netfs_sreq(subreq, netfs_sreq_trace_download_instead);
netfs_get_read_subrequest(subreq);
atomic_inc(&rreq->nr_rd_ops);
@ -414,6 +422,17 @@ void netfs_subreq_terminated(struct netfs_read_subrequest *subreq,
subreq->debug_index, subreq->start, subreq->flags,
transferred_or_error);
switch (subreq->source) {
case NETFS_READ_FROM_CACHE:
netfs_stat(&netfs_n_rh_read_done);
break;
case NETFS_DOWNLOAD_FROM_SERVER:
netfs_stat(&netfs_n_rh_download_done);
break;
default:
break;
}
if (IS_ERR_VALUE(transferred_or_error)) {
subreq->error = transferred_or_error;
goto failed;
@ -470,8 +489,10 @@ incomplete:
failed:
if (subreq->source == NETFS_READ_FROM_CACHE) {
netfs_stat(&netfs_n_rh_read_failed);
set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
} else {
netfs_stat(&netfs_n_rh_download_failed);
set_bit(NETFS_RREQ_FAILED, &rreq->flags);
rreq->error = subreq->error;
}
@ -653,6 +674,7 @@ void netfs_readahead(struct readahead_control *ractl,
rreq->start = readahead_pos(ractl);
rreq->len = readahead_length(ractl);
netfs_stat(&netfs_n_rh_readahead);
trace_netfs_read(rreq, readahead_pos(ractl), readahead_length(ractl),
netfs_read_trace_readahead);
@ -722,6 +744,7 @@ int netfs_readpage(struct file *file,
rreq->start = page_index(page) * PAGE_SIZE;
rreq->len = thp_size(page);
netfs_stat(&netfs_n_rh_readpage);
trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
netfs_get_read_request(rreq);

54
fs/netfs/stats.c Normal file
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@ -0,0 +1,54 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/* Netfs support statistics
*
* Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/export.h>
#include <linux/seq_file.h>
#include <linux/netfs.h>
#include "internal.h"
atomic_t netfs_n_rh_readahead;
atomic_t netfs_n_rh_readpage;
atomic_t netfs_n_rh_rreq;
atomic_t netfs_n_rh_sreq;
atomic_t netfs_n_rh_download;
atomic_t netfs_n_rh_download_done;
atomic_t netfs_n_rh_download_failed;
atomic_t netfs_n_rh_download_instead;
atomic_t netfs_n_rh_read;
atomic_t netfs_n_rh_read_done;
atomic_t netfs_n_rh_read_failed;
atomic_t netfs_n_rh_zero;
atomic_t netfs_n_rh_short_read;
atomic_t netfs_n_rh_write;
atomic_t netfs_n_rh_write_done;
atomic_t netfs_n_rh_write_failed;
void netfs_stats_show(struct seq_file *m)
{
seq_printf(m, "RdHelp : RA=%u RP=%u rr=%u sr=%u\n",
atomic_read(&netfs_n_rh_readahead),
atomic_read(&netfs_n_rh_readpage),
atomic_read(&netfs_n_rh_rreq),
atomic_read(&netfs_n_rh_sreq));
seq_printf(m, "RdHelp : ZR=%u sh=%u\n",
atomic_read(&netfs_n_rh_zero),
atomic_read(&netfs_n_rh_short_read));
seq_printf(m, "RdHelp : DL=%u ds=%u df=%u di=%u\n",
atomic_read(&netfs_n_rh_download),
atomic_read(&netfs_n_rh_download_done),
atomic_read(&netfs_n_rh_download_failed),
atomic_read(&netfs_n_rh_download_instead));
seq_printf(m, "RdHelp : RD=%u rs=%u rf=%u\n",
atomic_read(&netfs_n_rh_read),
atomic_read(&netfs_n_rh_read_done),
atomic_read(&netfs_n_rh_read_failed));
seq_printf(m, "RdHelp : WR=%u ws=%u wf=%u\n",
atomic_read(&netfs_n_rh_write),
atomic_read(&netfs_n_rh_write_done),
atomic_read(&netfs_n_rh_write_failed));
}
EXPORT_SYMBOL(netfs_stats_show);

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@ -166,5 +166,6 @@ extern int netfs_readpage(struct file *,
void *);
extern void netfs_subreq_terminated(struct netfs_read_subrequest *, ssize_t, bool);
extern void netfs_stats_show(struct seq_file *);
#endif /* _LINUX_NETFS_H */