Commit2ded1f1

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Adjust DSM and DSA slot usage constants (back-patch).

1. Previously, a DSA area would create up to four segments at each sizebefore doubling the size. After this commit, it will create only two ateach size, so it ramps up faster and therefore needs fewer slots.2. Previously, the total limit on DSM slots allowed for 2 per connection.Switch to 5 per connection.This back-patches commitd061ea2 from release 13 into 10-12 based on afield complaint.Discussion:https://postgr.es/m/CAO03teA%2BjE1qt5iWDWzHqaufqBsF6EoOgZphnazps_tr_jDPZA%40mail.gmail.comDiscussion:https://postgr.es/m/CA%2BhUKGL6H2BpGbiF7Lj6QiTjTGyTLW_vLR%3DSn2tEBeTcYXiMKw%40mail.gmail.com

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Lines changed: 1 addition & 6 deletions

Original file line number	Diff line number	Diff line change
`@@ -45,13 +45,8 @@`
`45`	`45`
`46`	`46`	`#definePG_DYNSHMEM_CONTROL_MAGIC0x9a503d32`
`47`	`47`
`48`		`-/*`
`49`		`- * There's no point in getting too cheap here, because the minimum allocation`
`50`		`- * is one OS page, which is probably at least 4KB and could easily be as high`
`51`		`- * as 64KB. Each currently sizeof(dsm_control_item), currently 8 bytes.`
`52`		`- */`
`53`	`48`	`#definePG_DYNSHMEM_FIXED_SLOTS64`
`54`		`-#definePG_DYNSHMEM_SLOTS_PER_BACKEND2`
	`49`	`+#definePG_DYNSHMEM_SLOTS_PER_BACKEND5`
`55`	`50`
`56`	`51`	`#defineINVALID_CONTROL_SLOT((uint32) -1)`
`57`	`52`

Lines changed: 1 addition & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -74,7 +74,7 @@`
`74`	`74`	`* dsm.c's limits on total number of segments), or limiting the total size`
`75`	`75`	`* an area can manage when using small pointers.`
`76`	`76`	`*/`
`77`		`-#defineDSA_NUM_SEGMENTS_AT_EACH_SIZE4`
	`77`	`+#defineDSA_NUM_SEGMENTS_AT_EACH_SIZE2`
`78`	`78`
`79`	`79`	`/*`
`80`	`80`	`* The number of bits used to represent the offset part of a dsa_pointer.`

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