8735978e7a
Originally, we palloc'd this buffer just barely big enough to hold the largest xlog record seen so far. It turns out that that can result in valgrind complaints, because some compilers will emit code that assumes it can safely fetch padding bytes at the end of a struct, and those padding bytes were unallocated so far as aset.c was concerned. We can fix that by MAXALIGN'ing the palloc request size, ensuring that it is big enough to include any possible padding that might've been omitted from the on-disk record. An additional objection to the original coding is that it could result in many repeated palloc cycles, in the worst case where we see a series of gradually larger xlog records. We can ameliorate that cheaply by imposing a minimum buffer size that's large enough for most xlog records. BLCKSZ/2 was chosen after a bit of discussion. In passing, remove an obsolete comment in struct xl_heap_new_cid that the combocid field is free due to alignment considerations. Perhaps that was true at some point, but it's not now. Back-patch to 9.5 where this code came in. Discussion: https://postgr.es/m/E1eHa4J-0006hI-Q8@gemulon.postgresql.org |
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| common | ||
| gin | ||
| gist | ||
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| heap | ||
| index | ||
| nbtree | ||
| rmgrdesc | ||
| spgist | ||
| tablesample | ||
| transam | ||
| Makefile | ||