> On Mar 30, 2024, at 12:26 PM, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > On Sat, Mar 30, 2024 at 04:26:09PM +0100, Jan Schunk wrote: >> Full test result: >> >> $ git bisect start v6.6 v6.5 >> Bisecting: 7882 revisions left to test after this (roughly 13 steps) >> [a1c19328a160c80251868dbd80066dce23d07995] Merge tag 'soc-arm-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc >> -- >> $ git bisect good >> Bisecting: 3935 revisions left to test after this (roughly 12 steps) >> [e4f1b8202fb59c56a3de7642d50326923670513f] Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost >> -- >> $ git bisect bad >> Bisecting: 2014 revisions left to test after this (roughly 11 steps) >> [e0152e7481c6c63764d6ea8ee41af5cf9dfac5e9] Merge tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux >> -- >> $ git bisect bad >> Bisecting: 975 revisions left to test after this (roughly 10 steps) >> [4a3b1007eeb26b2bb7ae4d734cc8577463325165] Merge tag 'pinctrl-v6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl >> -- >> $ git bisect good >> Bisecting: 476 revisions left to test after this (roughly 9 steps) >> [4debf77169ee459c46ec70e13dc503bc25efd7d2] Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd >> -- >> $ git bisect good >> Bisecting: 237 revisions left to test after this (roughly 8 steps) >> [e7e9423db459423d3dcb367217553ad9ededadc9] Merge tag 'v6.6-vfs.super.fixes.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs >> -- >> $ git bisect good >> Bisecting: 141 revisions left to test after this (roughly 7 steps) >> [8ae5d298ef2005da5454fc1680f983e85d3e1622] Merge tag '6.6-rc-ksmbd-fixes-part1' of git://git.samba.org/ksmbd >> -- >> $ git bisect good >> Bisecting: 61 revisions left to test after this (roughly 6 steps) >> [99d99825fc075fd24b60cc9cf0fb1e20b9c16b0f] Merge tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs >> -- >> $ git bisect bad >> Bisecting: 39 revisions left to test after this (roughly 5 steps) >> [7b719e2bf342a59e88b2b6215b98ca4cf824bc58] SUNRPC: change svc_recv() to return void. >> -- >> $ git bisect bad >> Bisecting: 19 revisions left to test after this (roughly 4 steps) >> [e7421ce71437ec8e4d69cc6bdf35b6853adc5050] NFSD: Rename struct svc_cacherep >> -- >> $ git bisect good >> Bisecting: 9 revisions left to test after this (roughly 3 steps) >> [baabf59c24145612e4a975f459a5024389f13f5d] SUNRPC: Convert svc_udp_sendto() to use the per-socket bio_vec array >> -- >> $ git bisect bad >> Bisecting: 4 revisions left to test after this (roughly 2 steps) >> [be2be5f7f4436442d8f6bffbb97a6f438df2896b] lockd: nlm_blocked list race fixes >> -- >> $ git bisect good >> Bisecting: 2 revisions left to test after this (roughly 1 step) >> [d424797032c6e24b44037e6c7a2d32fd958300f0] nfsd: inherit required unset default acls from effective set >> -- >> $ git bisect good >> Bisecting: 0 revisions left to test after this (roughly 1 step) >> [e18e157bb5c8c1cd8a9ba25acfdcf4f3035836f4] SUNRPC: Send RPC message on TCP with a single sock_sendmsg() call >> -- >> $ git bisect bad >> Bisecting: 0 revisions left to test after this (roughly 0 steps) >> [2eb2b93581813b74c7174961126f6ec38eadb5a7] SUNRPC: Convert svc_tcp_sendmsg to use bio_vecs directly >> -- >> $ git bisect good >> e18e157bb5c8c1cd8a9ba25acfdcf4f3035836f4 is the first bad commit >> commit e18e157bb5c8c1cd8a9ba25acfdcf4f3035836f4 > > This is a plausible bisect result for this behavior, so nice work. > > David (cc'd), can you have a brief look at this? What did we miss? > I'm guessing it's a page reference count issue that might occur > only when the XDR head and tail buffers are in the same page. Or > it might occur if two entries in the XDR page array point to the > same page...? > > /me stabs in the darkness > > >> I found the memory loss inside /proc/meminfo only on MemAvailable >> MemTotal: 346948 kB >> On a bad test run in looks like this: >> -MemAvailable: 210820 kB >> +MemAvailable: 26608 kB >> On a good test run it looks like this: >> -MemAvailable: 215872 kB >> +MemAvailable: 221128 kB Jan, may I ask one more favor? Since this might take a little time to run down, can you open a bug report on bugzilla.kernel.org <http://bugzilla.kernel.org/>, and copy in the symptomology and the bisect results? It will get assigned to Trond, and he can pass it to me. The problem looks like how we're using a page_frag_cache to handle the record marker buffers, but I'm not sure what the proper solution is yet. #regzbot ^introduced: e18e157bb5c8 -- Chuck Lever
