Chinwen Chang ff9f47f6f0 mm: proc: smaps_rollup: do not stall write attempts on mmap_lock ...

smaps_rollup will try to grab mmap_lock and go through the whole vma list
until it finishes the iterating.  When encountering large processes, the
mmap_lock will be held for a longer time, which may block other write
requests like mmap and munmap from progressing smoothly.

There are upcoming mmap_lock optimizations like range-based locks, but the
lock applied to smaps_rollup would be the coarse type, which doesn't avoid
the occurrence of unpleasant contention.

To solve aforementioned issue, we add a check which detects whether anyone
wants to grab mmap_lock for write attempts.

Signed-off-by: Chinwen Chang <chinwen.chang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Song Liu <songliubraving@fb.com>
Cc: Jimmy Assarsson <jimmyassarsson@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Daniel Kiss <daniel.kiss@arm.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Link: http://lkml.kernel.org/r/1597715898-3854-4-git-send-email-chinwen.chang@mediatek.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2020-10-13 18:38:31 -07:00

..

array.c

seccomp: Report number of loaded filters in /proc/$pid/status

2020-07-10 16:01:51 -07:00

base.c

mm, oom: make the calculation of oom badness more accurate

2020-08-12 10:57:56 -07:00

bootconfig.c

proc/bootconfig: Fix to use correct quotes for value

2020-06-16 21:21:03 -04:00

cmdline.c

proc: introduce proc_create_single{,_data}

2018-05-16 07:23:35 +02:00

consoles.c

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 191

2019-05-30 11:29:21 -07:00

cpuinfo.c

proc: faster open/read/close with "permanent" files

2020-04-07 10:43:42 -07:00

devices.c

block: move block-related definitions out of fs.h

2020-06-24 09:16:02 -06:00

fd.c

proc: use "unsigned int" in proc_fill_cache()

2018-06-07 17:34:38 -07:00

fd.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

generic.c

proc: add option to mount only a pids subset

2020-04-22 10:51:22 -05:00

inode.c

proc: Use new_inode not new_inode_pseudo

2020-06-12 14:13:33 -05:00

internal.h

proc: faster open/read/close with "permanent" files

2020-04-07 10:43:42 -07:00

interrupts.c

proc: introduce proc_create_seq{,_data}

2018-05-16 07:23:35 +02:00

Kconfig

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-14 01:57:21 +09:00

kcore.c

maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault

2020-06-17 10:57:41 -07:00

kmsg.c

proc: faster open/read/close with "permanent" files

2020-04-07 10:43:42 -07:00

loadavg.c

sched: loadavg: consolidate LOAD_INT, LOAD_FRAC, CALC_LOAD

2018-10-26 16:26:32 -07:00

Makefile

proc: bootconfig: Add /proc/bootconfig to show boot config list

2020-01-13 13:19:39 -05:00

meminfo.c

proc/meminfo: avoid open coded reading of vm_committed_as

2020-08-07 11:33:26 -07:00

namespaces.c

Merge branch 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-01-29 11:20:24 -08:00

nommu.c

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09 09:39:13 -07:00

page.c

mm: Add PG_arch_2 page flag

2020-09-04 12:46:06 +01:00

proc_net.c

bpf: Refactor to provide aux info to bpf_iter_init_seq_priv_t

2020-07-25 20:16:32 -07:00

proc_sysctl.c

Call sysctl_head_finish on error

2020-07-03 14:10:46 -04:00

proc_tty.c

tty: replace ->proc_fops with ->proc_show

2018-05-16 07:24:30 +02:00

root.c

proc: s_fs_info may be NULL when proc_kill_sb is called

2020-06-10 14:54:54 -05:00

self.c

proc: Use new_inode not new_inode_pseudo

2020-06-12 14:13:33 -05:00

softirqs.c

proc: introduce proc_create_single{,_data}

2018-05-16 07:23:35 +02:00

stat.c

proc: faster open/read/close with "permanent" files

2020-04-07 10:43:42 -07:00

task_mmu.c

mm: proc: smaps_rollup: do not stall write attempts on mmap_lock

2020-10-13 18:38:31 -07:00

task_nommu.c

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09 09:39:14 -07:00

thread_self.c

proc: Use new_inode not new_inode_pseudo

2020-06-12 14:13:33 -05:00

uptime.c

fs/proc: Respect boottime inside time namespace for /proc/uptime

2020-01-14 12:20:56 +01:00

util.c

fs/proc/util.c: include fs/proc/internal.h for name_to_int()

2019-01-04 13:13:45 -08:00

version.c

proc: introduce proc_create_single{,_data}

2018-05-16 07:23:35 +02:00

vmcore.c

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09 09:39:13 -07:00