Date: Sat, 26 Feb 2022 17:10:18 -0800 From: Mark Millard <marklmi@yahoo.com> To: Mark Johnston <markj@FreeBSD.org>, FreeBSD-STABLE Mailing List <freebsd-stable@freebsd.org> Cc: freebsd-current <freebsd-current@freebsd.org>, dev-commits-src-main@freebsd.org Subject: Re: git: 4a864f624a70 - main - vm_pageout: Print a more accurate message to the console before an OOM kill [MFC in time for 13.1?] Message-ID: <B052F35A-FD2C-4FAB-A3D6-D7D1B3C0AAED@yahoo.com> In-Reply-To: <YeLuZnR249sw3iCw@nuc> References: <1EF55D96-F7E3-4AA6-A331-782362A70878.ref@yahoo.com> <1EF55D96-F7E3-4AA6-A331-782362A70878@yahoo.com> <YeLuZnR249sw3iCw@nuc>
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On 2022-Jan-15, at 07:55, Mark Johnston <markj@FreeBSD.org> wrote:
> On Fri, Jan 14, 2022 at 09:38:56PM -0800, Mark Millard wrote:
>> Thanks. This will allow me to remove part of my personal additions
>> in this area --and my having to explain the misnomer when trying
>> to help someone analyze why they end up with OOM activity so they
>> can figure out what to do about it.
>>=20
>> There seem to be two separate sources of VM_OOM_SWAPZ. Showing
>> my personal additions for them (just making them explicit in the
>> sequence of messages generated):
>>=20
>> diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c
>> index 01cf9233329f..280621ca51be 100644
>> --- a/sys/vm/swap_pager.c
>> +++ b/sys/vm/swap_pager.c
>> @@ -2091,6 +2091,7 @@ swp_pager_meta_build(vm_object_t object, =
vm_pindex_t pindex, daddr_t swapblk)
>> 0, 1))
>> printf("swap blk zone =
exhausted, "
>> "increase =
kern.maxswzone\n");
>> + printf("swp_pager_meta_build: swap =
blk uma zone exhausted\n");
>> vm_pageout_oom(VM_OOM_SWAPZ);
>> pause("swzonxb", 10);
>> } else
>> @@ -2121,6 +2122,7 @@ swp_pager_meta_build(vm_object_t object, =
vm_pindex_t pindex, daddr_t swapblk)
>> 0, 1))
>> printf("swap pctrie zone =
exhausted, "
>> "increase =
kern.maxswzone\n");
>> + printf("swp_pager_meta_build: swap =
pctrie uma zone exhausted\n");
>> vm_pageout_oom(VM_OOM_SWAPZ);
>> pause("swzonxp", 10);
>> } else
>>=20
>> Care to comment on the distinctions and why there are two
>> contexts classified as "out of swap space"? Would either
>> one show the swap space as (nearly?) all used in, say, top?
>> Or might one of them still end up looking like a misnomer
>> from just a top (or whatever) display?
>=20
> Hmm, those cases should likely be changed from "out of swap space" to
> "failed to allocate swap metadata" or something like that.
The above does not seem to have happened yet in main [so: 14].
Will 13.1 get an MFC of 4a864f624a70 in time, possibly with the
above change also in place to fully avoid misnomer reporting
that misleads folks?
4a864f624a70 listed:
MFC after: 2 weeks
but it has been more than a month.
> . . .
>=20
=3D=3D=3D
Mark Millard
marklmi at yahoo.com
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