mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 21:51:40 +00:00
b6273b55d8
To allow precise tracking of page caches accessed, add new tracepoints that trigger when a process actually accesses them. The ureadahead program used by ChromeOS traces the disk access of programs as they start up at boot up. It uses mincore(2) or the 'mm_filemap_add_to_page_cache' trace event to accomplish this. It stores this information in a "pack" file and on subsequent boots, it will read the pack file and call readahead(2) on the information so that disk storage can be loaded into RAM before the applications actually need it. A problem we see is that due to the kernel's readahead algorithm that can aggressively pull in more data than needed (to try and accomplish the same goal) and this data is also recorded. The end result is that the pack file contains a lot of pages on disk that are never actually used. Calling readahead(2) on these unused pages can slow down the system boot up times. To solve this, add 3 new trace events, get_pages, map_pages, and fault. These will be used to trace the pages are not only pulled in from disk, but are actually used by the application. Only those pages will be stored in the pack file, and this helps out the performance of boot up. With the combination of these 3 new trace events and mm_filemap_add_to_page_cache, we observed a reduction in the pack file by 7.3% - 20% on ChromeOS varying by device. Link: https://lkml.kernel.org/r/20240813100312.3930505-1-takayas@chromium.org Signed-off-by: Takaya Saeki <takayas@chromium.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Junichi Uekawa <uekawa@chromium.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
203 lines
4.6 KiB
C
203 lines
4.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#undef TRACE_SYSTEM
|
|
#define TRACE_SYSTEM filemap
|
|
|
|
#if !defined(_TRACE_FILEMAP_H) || defined(TRACE_HEADER_MULTI_READ)
|
|
#define _TRACE_FILEMAP_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/tracepoint.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/memcontrol.h>
|
|
#include <linux/device.h>
|
|
#include <linux/kdev_t.h>
|
|
#include <linux/errseq.h>
|
|
|
|
DECLARE_EVENT_CLASS(mm_filemap_op_page_cache,
|
|
|
|
TP_PROTO(struct folio *folio),
|
|
|
|
TP_ARGS(folio),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned long, pfn)
|
|
__field(unsigned long, i_ino)
|
|
__field(unsigned long, index)
|
|
__field(dev_t, s_dev)
|
|
__field(unsigned char, order)
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->pfn = folio_pfn(folio);
|
|
__entry->i_ino = folio->mapping->host->i_ino;
|
|
__entry->index = folio->index;
|
|
if (folio->mapping->host->i_sb)
|
|
__entry->s_dev = folio->mapping->host->i_sb->s_dev;
|
|
else
|
|
__entry->s_dev = folio->mapping->host->i_rdev;
|
|
__entry->order = folio_order(folio);
|
|
),
|
|
|
|
TP_printk("dev %d:%d ino %lx pfn=0x%lx ofs=%lu order=%u",
|
|
MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
|
|
__entry->i_ino,
|
|
__entry->pfn,
|
|
__entry->index << PAGE_SHIFT,
|
|
__entry->order)
|
|
);
|
|
|
|
DEFINE_EVENT(mm_filemap_op_page_cache, mm_filemap_delete_from_page_cache,
|
|
TP_PROTO(struct folio *folio),
|
|
TP_ARGS(folio)
|
|
);
|
|
|
|
DEFINE_EVENT(mm_filemap_op_page_cache, mm_filemap_add_to_page_cache,
|
|
TP_PROTO(struct folio *folio),
|
|
TP_ARGS(folio)
|
|
);
|
|
|
|
DECLARE_EVENT_CLASS(mm_filemap_op_page_cache_range,
|
|
|
|
TP_PROTO(
|
|
struct address_space *mapping,
|
|
pgoff_t index,
|
|
pgoff_t last_index
|
|
),
|
|
|
|
TP_ARGS(mapping, index, last_index),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned long, i_ino)
|
|
__field(dev_t, s_dev)
|
|
__field(unsigned long, index)
|
|
__field(unsigned long, last_index)
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->i_ino = mapping->host->i_ino;
|
|
if (mapping->host->i_sb)
|
|
__entry->s_dev =
|
|
mapping->host->i_sb->s_dev;
|
|
else
|
|
__entry->s_dev = mapping->host->i_rdev;
|
|
__entry->index = index;
|
|
__entry->last_index = last_index;
|
|
),
|
|
|
|
TP_printk(
|
|
"dev=%d:%d ino=%lx ofs=%lld-%lld",
|
|
MAJOR(__entry->s_dev),
|
|
MINOR(__entry->s_dev), __entry->i_ino,
|
|
((loff_t)__entry->index) << PAGE_SHIFT,
|
|
((((loff_t)__entry->last_index + 1) << PAGE_SHIFT) - 1)
|
|
)
|
|
);
|
|
|
|
DEFINE_EVENT(mm_filemap_op_page_cache_range, mm_filemap_get_pages,
|
|
TP_PROTO(
|
|
struct address_space *mapping,
|
|
pgoff_t index,
|
|
pgoff_t last_index
|
|
),
|
|
TP_ARGS(mapping, index, last_index)
|
|
);
|
|
|
|
DEFINE_EVENT(mm_filemap_op_page_cache_range, mm_filemap_map_pages,
|
|
TP_PROTO(
|
|
struct address_space *mapping,
|
|
pgoff_t index,
|
|
pgoff_t last_index
|
|
),
|
|
TP_ARGS(mapping, index, last_index)
|
|
);
|
|
|
|
TRACE_EVENT(mm_filemap_fault,
|
|
TP_PROTO(struct address_space *mapping, pgoff_t index),
|
|
|
|
TP_ARGS(mapping, index),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned long, i_ino)
|
|
__field(dev_t, s_dev)
|
|
__field(unsigned long, index)
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->i_ino = mapping->host->i_ino;
|
|
if (mapping->host->i_sb)
|
|
__entry->s_dev =
|
|
mapping->host->i_sb->s_dev;
|
|
else
|
|
__entry->s_dev = mapping->host->i_rdev;
|
|
__entry->index = index;
|
|
),
|
|
|
|
TP_printk(
|
|
"dev=%d:%d ino=%lx ofs=%lld",
|
|
MAJOR(__entry->s_dev),
|
|
MINOR(__entry->s_dev), __entry->i_ino,
|
|
((loff_t)__entry->index) << PAGE_SHIFT
|
|
)
|
|
);
|
|
|
|
TRACE_EVENT(filemap_set_wb_err,
|
|
TP_PROTO(struct address_space *mapping, errseq_t eseq),
|
|
|
|
TP_ARGS(mapping, eseq),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned long, i_ino)
|
|
__field(dev_t, s_dev)
|
|
__field(errseq_t, errseq)
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->i_ino = mapping->host->i_ino;
|
|
__entry->errseq = eseq;
|
|
if (mapping->host->i_sb)
|
|
__entry->s_dev = mapping->host->i_sb->s_dev;
|
|
else
|
|
__entry->s_dev = mapping->host->i_rdev;
|
|
),
|
|
|
|
TP_printk("dev=%d:%d ino=0x%lx errseq=0x%x",
|
|
MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
|
|
__entry->i_ino, __entry->errseq)
|
|
);
|
|
|
|
TRACE_EVENT(file_check_and_advance_wb_err,
|
|
TP_PROTO(struct file *file, errseq_t old),
|
|
|
|
TP_ARGS(file, old),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(struct file *, file)
|
|
__field(unsigned long, i_ino)
|
|
__field(dev_t, s_dev)
|
|
__field(errseq_t, old)
|
|
__field(errseq_t, new)
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->file = file;
|
|
__entry->i_ino = file->f_mapping->host->i_ino;
|
|
if (file->f_mapping->host->i_sb)
|
|
__entry->s_dev =
|
|
file->f_mapping->host->i_sb->s_dev;
|
|
else
|
|
__entry->s_dev =
|
|
file->f_mapping->host->i_rdev;
|
|
__entry->old = old;
|
|
__entry->new = file->f_wb_err;
|
|
),
|
|
|
|
TP_printk("file=%p dev=%d:%d ino=0x%lx old=0x%x new=0x%x",
|
|
__entry->file, MAJOR(__entry->s_dev),
|
|
MINOR(__entry->s_dev), __entry->i_ino, __entry->old,
|
|
__entry->new)
|
|
);
|
|
#endif /* _TRACE_FILEMAP_H */
|
|
|
|
/* This part must be outside protection */
|
|
#include <trace/define_trace.h>
|