From: Minchan Kim <minchan@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alexander Duyck <alexander.h.duyck@linux.intel.com>,
Jens Axboe <axboe@kernel.dk>, Brian Geffon <bgeffon@google.com>,
Christian Brauner <christian.brauner@ubuntu.com>,
Christian Brauner <christian@brauner.io>,
Daniel Colascione <dancol@google.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Jann Horn <jannh@google.com>, John Dias <joaodias@google.com>,
Joel Fernandes <joel@joelfernandes.org>,
Kirill Tkhai <ktkhai@virtuozzo.com>,
linux-man <linux-man@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>, Michal Hocko <mhocko@suse.com>,
mm-commits@vger.kernel.org,
Oleksandr Natalenko <oleksandr@redhat.com>,
David Rientjes <rientjes@google.com>,
Shakeel Butt <shakeelb@google.com>,
sj38.park@gmail.com, sjpark@amazon.de,
Sonny Rao <sonnyrao@google.com>,
Sandeep Patil <sspatil@google.com>,
Suren Baghdasaryan <surenb@google.com>,
Tim Murray <timmurray@google.com>,
Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [patch 18/39] mm/madvise: check fatal signal pending of target process
Date: Fri, 14 Aug 2020 21:59:00 -0700 [thread overview]
Message-ID: <20200815045900.GA2936603@google.com> (raw)
In-Reply-To: <CAHk-=wgZ6ZgRWRm0rGgLkYR-_XwKeuWxwbkBWxmCOzt7dGxWpg@mail.gmail.com>
On Fri, Aug 14, 2020 at 07:53:09PM -0700, Linus Torvalds wrote:
> On Fri, Aug 14, 2020 at 5:31 PM Andrew Morton <akpm@linux-foundation.org> wrote:
> >
> > From: Minchan Kim <minchan@kernel.org>
> > Subject: mm/madvise: check fatal signal pending of target process
> >
> > Bail out to prevent unnecessary CPU overhead if target process has pending
> > fatal signal during (MADV_COLD|MADV_PAGEOUT) operation.
>
> This seems bogus.
>
> Returning -EINTR when *SOMEBODY ELSE* has a signal is crazy talk.
It doesn't propagate -EINTR to the user but just aiming for canceling
the entire operation.
>
> It also seems to be the reason for the previous patches inexplicably
> passing in the task pointer.
>
> Finally, it has absolutely no explanations for why this would matter,
> and why it's magically and suddenly an issue for process_madvise(),
> when in the history of the *real* madvise() this hasn't been an issue
> for "current".
Currently, madvise(MADV_COLD|PAGEOUT) already have done it. I just wanted
to sync with it with process_madvise. Ting was process_madvise couldn't
get target task while madvise could get it easily.
>
> I'm dropping the madvise() series.
>
> If the issue is that you can generate a long series or areas with that
> iovec, maybe the code should re-consider. Or maybe the signal pending
> case should be done there, not passing down an odd task pointer to the
> low-level madvise code.
Do you mean you want to drop target signal check madvise as well as
process_madvise?
next prev parent reply other threads:[~2020-08-15 4:59 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-15 0:29 incoming Andrew Morton
2020-08-15 0:30 ` [patch 01/39] asm-generic: pgalloc.h: use correct #ifdef to enable pud_alloc_one() Andrew Morton
2020-08-15 0:30 ` [patch 02/39] Revert "mm/vmstat.c: do not show lowmem reserve protection information of empty zone" Andrew Morton
2020-08-15 0:30 ` [patch 03/39] lz4: fix kernel decompression speed Andrew Morton
2020-08-15 0:30 ` [patch 04/39] exec: restore EACCES of S_ISDIR execve() Andrew Morton
2020-08-15 0:30 ` [patch 05/39] selftests/exec: add file type errno tests Andrew Morton
2020-08-15 0:30 ` [patch 06/39] mailmap: add entry for Greg Kurz Andrew Morton
2020-08-15 0:30 ` [patch 07/39] mm: store compound_nr as well as compound_order Andrew Morton
2020-08-15 0:30 ` [patch 08/39] mm: move page-flags include to top of file Andrew Morton
2020-08-15 0:30 ` [patch 09/39] mm: add thp_order Andrew Morton
2020-08-15 0:30 ` [patch 10/39] mm: add thp_size Andrew Morton
2020-08-15 0:30 ` [patch 11/39] mm: replace hpage_nr_pages with thp_nr_pages Andrew Morton
2020-08-15 0:30 ` [patch 12/39] mm: add thp_head Andrew Morton
2020-08-15 0:30 ` [patch 13/39] mm: introduce offset_in_thp Andrew Morton
2020-08-15 0:30 ` [patch 14/39] fs: autofs: delete repeated words in comments Andrew Morton
2020-08-15 0:30 ` [patch 15/39] mm/madvise: pass task and mm to do_madvise Andrew Morton
2020-08-15 0:30 ` [patch 16/39] pid: move pidfd_get_pid() to pid.c Andrew Morton
2020-08-15 0:30 ` [patch 17/39] mm/madvise: introduce process_madvise() syscall: an external memory hinting API Andrew Morton
2020-08-16 8:12 ` Christian Brauner
2020-08-17 15:10 ` Minchan Kim
2020-08-15 0:31 ` [patch 18/39] mm/madvise: check fatal signal pending of target process Andrew Morton
2020-08-15 2:53 ` Linus Torvalds
2020-08-15 4:59 ` Minchan Kim [this message]
2020-08-15 14:57 ` Linus Torvalds
2020-08-15 18:34 ` Minchan Kim
2020-08-16 1:43 ` Linus Torvalds
2020-08-16 5:58 ` Minchan Kim
2020-08-15 0:31 ` [patch 19/39] all arch: remove system call sys_sysctl Andrew Morton
2020-08-15 0:31 ` [patch 20/39] mm/kmemleak: silence KCSAN splats in checksum Andrew Morton
2020-08-15 0:31 ` [patch 21/39] mm/frontswap: mark various intentional data races Andrew Morton
2020-08-15 0:31 ` [patch 22/39] mm/page_io: " Andrew Morton
2020-08-15 0:31 ` [patch 23/39] mm/swap_state: " Andrew Morton
2020-08-15 0:31 ` [patch 24/39] mm/filemap.c: fix a data race in filemap_fault() Andrew Morton
2020-08-15 0:31 ` [patch 25/39] mm/swapfile: fix and annotate various data races Andrew Morton
2020-08-15 0:31 ` [patch 26/39] mm/page_counter: fix various data races at memsw Andrew Morton
2020-08-15 0:31 ` [patch 27/39] mm/memcontrol: fix a data race in scan count Andrew Morton
2020-08-15 0:31 ` [patch 28/39] mm/list_lru: fix a data race in list_lru_count_one Andrew Morton
2020-08-15 0:31 ` [patch 29/39] mm/mempool: fix a data race in mempool_free() Andrew Morton
2020-08-15 0:31 ` [patch 30/39] mm/rmap: annotate a data race at tlb_flush_batched Andrew Morton
2020-08-15 0:31 ` [patch 31/39] mm/swap.c: annotate data races for lru_rotate_pvecs Andrew Morton
2020-08-15 0:31 ` [patch 32/39] mm: annotate a data race in page_zonenum() Andrew Morton
2020-08-15 0:31 ` [patch 33/39] include/asm-generic/vmlinux.lds.h: align ro_after_init Andrew Morton
2020-08-15 0:32 ` [patch 34/39] sh: clkfwk: remove r8/r16/r32 Andrew Morton
2020-08-15 0:32 ` [patch 35/39] sh: use generic strncpy() Andrew Morton
2020-08-15 0:32 ` [patch 36/39] iomap: constify ioreadX() iomem argument (as in generic implementation) Andrew Morton
2020-08-15 0:32 ` [patch 37/39] rtl818x: " Andrew Morton
2020-08-15 0:32 ` [patch 38/39] ntb: intel: " Andrew Morton
2020-08-15 0:32 ` [patch 39/39] virtio: pci: " Andrew Morton
2020-08-19 23:09 ` mmotm 2020-08-19-16-09 uploaded Andrew Morton
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